mm-108 Please explain what you meant by Even Homer nods. Is it a nod > of assent?You betray your lack of a classical education by that question.Homer, of Iliad and Odyssey fame, was considered the ultimate poet and storyteller, and the ideal model for all those who follow him, but he did make some minor errors in his two great works. Those noting the errors usually also note that, as great as he was, even Homer nods (Homer dormitat). Im not versed in classics. Classic rock, sure, Ive probably heardit and may know the band, classic tragedies, comedies, and epics, lessso. La commedia es la tragedia. I think the rst book with morethan a hundred pages I read was a childrens Popeye novel that hadscenes that reminded me of Scylla and Charybdis. The Dungeons andDragons Monster Manuals and Deities and Demigods summarized someaspects of the pantheons members, mythical beasts, and otherfantastic creatures, such as their hit points, immunities, etcetera. I centaur has 4d8 hit points, or four hit dice, 4d-8d. Heh,Sahaugin (sa-HOO-jen). I have 74 hit points, immunity to drizzle, andin some venues, a power st. Also, I y, and lasers shoot out of myeyes.Homer, take a bow. I cant string my own damn bow, it has to go in apress, it has more than a 70 pound draw weight, 35% let-off, speedcams. Twang, it pings. It puts some arrows _through_ the eternaltarget. Im proud of it.http://www.pagebypagebooks.com/Homer_Butler_Tr/The_Odyssey Studies/Greek/Homer/http://www.perseus.tufts.edu/cache/ perscoll_Greco-Roman.htmlDid you ever read Philip Jose Farmers Riverworld Series? It hadUlysses, Odysseus, but it wasnt actually Ulysses, it was Loga. Mythof Sisyphus, indeed.Even Homer plauds. (...)So anyways were talking about normal numbers. The number normal tobase two appears to have a binary zero-density of one-half. Theexpression n!/ (n/2)!^2 2^n evaluates asymptotically to, what was thatagain, sqrt ( pi/ 2 n)? I thought it would be 1/2. Now Im hearingthat almost all irrationals are absolutely normal. Splitting thedifference between almost all and almost none is around one half.Ross Splitting the> difference between almost all and almost none is around one half.RossSplitting the difference between almost all and almost none in a real interval is almost anything in between.Unless some highly specic splitting mechanism is guaranteed. Each player takes turns coming up with algorithmic steps, one step at> a time in sequence, each step giving a rule to transform an integer> into another.(such as: multiply m by greatest prime p, where p divides m and is < sqrt(|m|). If no such prime exists, leave m unchanged.)> (or such as: m = oor(|m|/d(|m|)), where d(m) is number of positive> divisors of m.)> (or rules may involve meta-transformations, such as sending players to> previous rules, depending somehow upon the value of the integer when> reaching the step.)Anyway, players are encouraged to be creative when inventing rules!> Each step is capable of transforming any integer, always giving an> integer as output.After a predetermined number of steps have been created (the same> number for each player), a random integer is generated somehow.Players then try to guess what the output intger will be.The algorithm is run using the random start-integer. The winner of the game is the player who comes closest to guessing the> (needs work....)Of course, there should be a time limit between when the randominteger is picked (after the list of rules is completed) and when theplayers must submit their predictions as to what will be the output ofthe algorithm.(Otherwise, each player could just go through the algorithm manually,each player perhaps predicting the output exactly...)Leroy Quet Let m be a xed positive integer.Let x be a xed positive real.Let n(m,x) be the highest positive integer such that1/m + 1/(m+1) + 1/(m+2) + ...+ 1/n(m,x) <= x.> A lot of questions can be asked about this.But what I am wondering now is, what is:E(m,x) = x - (1/m + 1/(m+1) + 1/(m+2) + ...+ 1/n(m,x))asymptotical to?All this is highly related to the topic off&threadm=agt133%24ek%241%40nntp.itservices.ubc.ca&rnum=1& prev Now, m does not have to be an integer.(But the number of terms in the sum is an integer. n(y,x) = y + integer.)So, if we plot w = E(y,x), for xed x, what does the graph look like?(My copy of Mathematica got fried.)Is it continuous, for By the way, I might as well add this:>exp(sum{p=primes} 1/p^x) = >>sum{k=1 to oo} A(k)/k^x,>where A(k) = product{p=primes} 1/(a(p,k))! ,>>and where each a(p,k) is a nonnegative integer such that>>p^a(p,k) is the highest power of the prime p which divides k.>>(I think...)I think so, too. In other words the coefcient of n^{-x} in > exp(sum_p p^{-x}) is 1/prod_i k_i! if n=prod_i p_i^{k_i}.However, returning to the OP, today I made a few other calculations> and found out that *formally*sum_p p^{-x} = sum_{k=1}^{infty} mu(n)/n log(zeta(nx)).There do not *seem* to be any issues suggesting that this equality> should not hold also in the analytical sense, but what interests me> most is that as I had guessed initially this function once again seems> to be independent of zeta in the sense that it cannot be expressed> in terms of zeta by means of (a nite number of) algebraic> operations, composition with elementary functions and/or derivation.> Am I right?> MicheleI forgot to mention this webpage:http://mathworld.wolfram.com/PrimeZetaFunction.htmlIt seems to have a lot of info on what is known as the prime zeta function.Yes, this sum is well-known, but still =Ive seen one cataloged, as it were; ifIfind the book, Ill get the authors. > Has a single polygon that tiles the plane only aperiodically been found,> or proved not to exist, or is this still an open question?--Dec.2000 WAND Chairman Paul ONeill, reelected to Board. Newsish?http://www.rand.org/publications/randreview/issues/rr .12.00/http://members.tripod.com/~american_almanac =Suppose H is a hash function with N-bit output. Dene h_n to be H restricted to n-bit input (1 <= n <= N), and take h_n(x) to be the rst n bits of H(x). (1) Referring to n-bit strings by the integers they represent in binary, let p(n) be the proportion of values 0, ..., 2^n-1*missing* from the range of h_n, i.e.,p(n) = ( #duplicates among h_n(0), ..., h_n(2^n-1) ) / 2^n.Are there theoretical values to be expected for the p(n)?(2) When H is SHA-1 (N = 160), Ifind the valuesp(2^8) = 90/256 ~ 35%p(2^16) = 24100/65536 ~ 38%.What is a reasonable value to expect for p(2^160)?BCgNrSjVlRhxQXcdZzWpGFLtDswMkHvqPnTKJmbf (1) Referring to n-bit strings by the integers they represent >in binary, let p(n) be the proportion of values 0, ..., 2^n-1>*missing* from the range of h_n, >Are there theoretical values to be expected for the p(n)?1/e ~= 0.36787944117144232159http://www.cs.berkeley.edu/~daw/ my-posts/hash-iteration =| >(1) Referring to n-bit strings by the integers they represent | >in binary, let p(n) be the proportion of values 0, ..., 2^n-1| >*missing* from the range of h_n, | >Are there theoretical values to be expected for the p(n)?| | 1/e ~= 0.36787944117144232159| | http://www.cs.berkeley.edu/~daw/my-posts/hash-iterationhttp:/ /www.cs.berkeley.edu/~daw/my-posts/random-mapsfrom which I think the following is clear:If |X| < oo, and f: X -> X is a random function such that for all x,y in X, P( f(x) = y ) = 1/|X|, then E |X - f(X)| / |X| = (1 - 1/|X|)^|X|.In the present context, X is the set of n-bit stringsand h_n is apparently to be treated like h, giving us E p(n) = E |X - h_n(X)| / |X| ~ 1/e.But why can we treat h_n (a given, non-random function-- say the restriction of SHA-1) as though its random? E.g., why and in what sense do we have P( h_n(x) = y ) = 1/2^n? why can we treat h_n (a given, non-random function> -- say the restriction of SHA-1) as though its random? If we take SHA1, by internal contruction for small number of bits,the output is S1 = S0 ^ ENC(paddedMessage, S0)where S0 is a xed constant (160 bits), andC = ENC(K,P) is a cipher with K 512 bits, P and C 160 bits.On the assumption that the cipher is perfect [any distinct Krandomly selects a mapping from P to C among (2^160)!], you candemonstrate properties on duplicates in h_n.Without more precision than H is a hash function with N-bit outputyou cant. For example, consider the following hash function,dened on same input and output domain as SHA1- for input up to 158 bits, output is the input, followed by just enough bits at 0 to reach 158 bits, followed by two bits at 1- for input of 159 bits or more, the output is that of SHA1, with the last bit set to 0.This pathological hash function enjoys excellent second premimageresistance (and thus is perfectly suitable to protect the integrityof a le). But p(n)=0 for all n<=158, and p(160) >> 1/e.A less pathological example is H = SHA(SHA1(M)); it experimentalyhas properties similar to SHA1 (including experimentalindistinguishibility from random, and preimage resistance),but p(160) >> 1/e. Fran.8dois GrieuOriginal problem quated below> Suppose H is a hash function with N-bit output. Dene h_n > to be H restricted to n-bit input (1 <= n <= N), and take > h_n(x) to be the rst n bits of H(x). > (1) Referring to n-bit strings by the integers they represent > in binary, let p(n) be the proportion of values 0, ..., 2^n-1> *missing* from the range of h_n, i.e.,> p(n) = ( #duplicates among h_n(0), ..., h_n(2^n-1) ) / 2^n.> Are there theoretical values to be expected for the p(n)?(2) When H is SHA-1 (N = 160), Ifind the values> p(8) = 90/256 ~ 35%> p(16) = 24100/65536 ~ 38%.> What is a reasonable value to expect for p(160)? >why can we treat h_n (a given, non-random function>>-- say the restriction of SHA-1) as though its random? > If we take SHA1, by internal contruction for small number of bits,> the output is S1 = S0 ^ ENC(paddedMessage, S0) The ^ is more like a +, although, since its 5 separate 32-bit additions, its not really + either.> where S0 is a xed constant (160 bits), and> C = ENC(K,P) is a cipher with K 512 bits, P and C 160 bits.> On the assumption that the cipher is perfect [any distinct K> randomly selects a mapping from P to C among (2^160)!], you can> demonstrate properties on duplicates in h_n.Without more precision than H is a hash function with N-bit output> you cant. For example, consider the following hash function,> dened on same input and output domain as SHA1> - for input up to 158 bits, output is> the input, > followed by just enough bits at 0 to reach 158 bits,> followed by two bits at 1> - for input of 159 bits or more, the output is that of SHA1,> with the last bit set to 0.This pathological hash function enjoys excellent second premimage> resistance (and thus is perfectly suitable to protect the integrity> of a le). But p(n)=0 for all n<=158, and p(160) >> 1/e.A less pathological example is H = SHA(SHA1(M)); it experimentaly> has properties similar to SHA1 (including experimental> indistinguishibility from random, and preimage resistance),> but p(160) >> 1/e. This also applies to H=SHA1(SHA1(M)).--Mike Amling | >(1) Referring to n-bit strings by the integers they represent > | >in binary, let p(n) be the proportion of values 0, ..., 2^n-1> | >*missing* from the range of h_n, > | >Are there theoretical values to be expected for the p(n)?> | > | 1/e ~= 0.36787944117144232159> | > | http://www.cs.berkeley.edu/~daw/my-posts/hash-iterationhttp:/ /www.cs.berkeley.edu/~daw/my-posts/random-maps> from which I think the following is clear:If |X| < oo, and f: X -> X is a random function > such that for all x,y in X, P( f(x) = y ) = 1/|X|, > then E |X - f(X)| / |X| = (1 - 1/|X|)^|X|.In the present context, X is the set of n-bit strings> and h_n is apparently to be treated like h, giving us > E p(n) = E |X - h_n(X)| / |X| ~ 1/e.But why can we treat h_n (a given, non-random function> -- say the restriction of SHA-1) as though its random? Because no distinguisher has been found that can differentiate between SHA-1 output (from unknown input) and random output?> E.g., why and in what sense do we have > P( h_n(x) = y ) = 1/2^n? The measured probabilities of SHA-1 outputs (truncated to n bits) are statistically indistinguishable from 2**-n.--Mike Amling = [referring to David Wagners posting]| > I think the following is clear:In this little theorem, X is supposed to be non-empty:| > If [0 <] |X| < oo, and f: X -> X is a random function | > such that for all x,y in X, P( f(x) = y ) = 1/|X|, | > then E |X - f(X)| / |X| = (1 - 1/|X|)^|X|.| > In the present context, X is the set of n-bit strings| > and h_n is apparently to be treated like h, giving us | > E p(n) = E |X - h_n(X)| / |X| ~ 1/e.| > | > But why can we treat h_n (a given, non-random function| > -- say the restriction of SHA-1) as though its random? | | Because no distinguisher has been found that can differentiate | between SHA-1 output (from unknown input) and random output?That has to be relevant, but its just not clear how. The trouble is that the theorem does not refer to randomness of inputs or outputs -- its the *mapping* thats random.E.g., in the 1-bit case with h_1 = SHA1 = (restricted)SHA-1,the expression P( SHA1(0) = 0 ) = 1/2 makes no sense, because SHA1 is not a random mapping.| > E.g., why and in what sense do we have | > P( h_n(x) = y ) = 1/2^n?| | The measured probabilities of SHA-1 outputs (truncated to n bits) | are statistically indistinguishable from 2**-n.Again, this 1/2^n result does not refer to randomness of the inputs or outputs, but to randomness of the mapping (and SHA1is a known xed mapping). To make the issue clearer, consider the simple 1-bit case ...There are 4 possible mappings {0,1} -> {0,1}, and the above theorem applies when these mappings are equally likely: mapping probability------------------- -----------f1: 0 -> 0, 1 -> 0 1/4f2: 0 -> 0, 1 -> 1 1/4f3: 0 -> 1, 1 -> 0 1/4f4: 0 -> 1, 1 -> 1 1/4For the random function f dened by this distribution,P( f(0) = 0 ) = P( {f1, f2} ) = 1/2, andE p(1) = E |{0,1} - f({0,1})| / 2 = (1/2)/2 = 1/4.In the n-bit case, there are 2^n equally-likely mappings, exactly one of which corresponds to SHA-l. So something more is needed to explain the behavior of a specic one of these mappings. =Yes. Im using the random oracle model; replace the (xed)hash function by a random function, do your computations assumingyoure dealing with a random function, and then hope that yourcomputations carry over to the real, xed hash function.This is only a heuristic -- but it seems to be a darn effective one. =[typo corrections]Suppose H is a hash function with N-bit output. Dene h_n to be H restricted to n-bit input (1 <= n <= N), and take h_n(x) to be the rst n bits of H(x). (1) Referring to n-bit strings by the integers they represent in binary, let p(n) be the proportion of values 0, ..., 2^n-1*missing* from the range of h_n, i.e.,p(n) = ( #duplicates among h_n(0), ..., h_n(2^n-1) ) / 2^n.Are there theoretical values to be expected for the p(n)?(2) When H is SHA-1 (N = 160), Ifind the valuesp(8) = 90/256 ~ 35%p(16) = 24100/65536 ~ 38%.What is a reasonable value to expect for p(160)?BCgNrSjVlRhxQXcdZzWpGFLtDswMkHvqPnTKJmbf What is the family of real -> real analytic functions f(x), such there are an innite number of fs,not necessarily continuous.As to determine f(x) for all positive x, just dene the interval from>0 to 1 arbitrarily (but I suggest all of it be > 0 to avoid undenedf(x)s at any x), and then get the rest of f(x), for positive x,recursively.(Duh, but must What is the family of real -> real analytic functions f(x), such that:> f(x+1) = f(x) + 1/f(x)> for all real x?>> Even if there is no analytic f, there are an innite number of fs,> not necessarily continuous.>> As to determine f(x) for all positive x, just dene the interval from>0 to 1 arbitrarily (but I suggest all of it be > 0 to avoid undened> f(x)s at any x), and then get the rest of f(x), for positive x,> recursively.>Would you work that out? Ive much doubt.See my reply to Herman Rubin where I extend his method.There I show f(x) = +-oo for all x. Am I correct? What is the family of real -> real analytic functions f(x), such that:> f(x+1) = f(x) + 1/f(x)> for all real x?>> Even if there is no analytic f, there are an innite number of fs,> not necessarily continuous.>> As to determine f(x) for all positive x, just dene the interval from>0 to 1 arbitrarily (but I suggest all of it be > 0 to avoid undened> f(x)s at any x), and then get the rest of f(x), for positive x,> recursively.>> Would you work that out? Ive much doubt.> See my reply to Herman Rubin where I extend his method.> There I show f(x) = +-oo for all x. Am I correct?Ah, I was thinking only in terms of the function being denedjust for *positive* real x, not for all real x.My mistake.If the relation need only be true for all x > some constant X, then weshould be able to get a dened (but not analytic) function f, atleast when f is positive for all x > What is the family of real -> real analytic functions f(x), such that:>f(x+1) = f(x) + 1/f(x)>for all real x?>Ah, I was thinking only in terms of the function being dened>just for *positive* real x, not for all real x.>If the relation need only be true for all x > some constant X, then we>should be able to get a dened (but not analytic) function f, at>least when f is positive for all x > X.It might be interesting to try for solutions that are analytic in somedomain. f(x) = 0 produces a pole at x+1. On the other hand, f(x) = 2is likely to produce a branch point at x-1.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 Is a limit point compact subspace of a Hausdorff space necessarilyclosed?>> I suppose that a limit point compact subspace is a subspace such that> each sequence has a convergent subsequence. The usual expression for> that is sequencially compact.>The denition of a limit point compact space is such that every innitesubset of that space has a limit point. Sequential compactness is only anequivalent denition when the space is metrizable.> Well since I cant seem to prove this and since if this is true, theproof> would look nothing like the proof that a compact subspace of a Hausdorff> space is closed, I am trying to come up with a counterexample.>> Let S be the rst uncountable ordinal and consider the set [0,S] of all> ordinals smaller or equal than S, endowed with the topology generated by> all open intervals ]a,b[. Then [0,S[ is sequentially compact, but it is> not a closed subset.>> However, if you add the hypothesis that your space X is not only Hausdorff> but also rst countable, then it is true that any sequentially compact> subspace Y is a closed subset. If this was not the case, you could take a> point p that belongs to the closure of Y but not to Y and a sequence y_1,> y_2, ... of points of Y that converges to y. Since Y is sequentially> compact, then some subsequence converges to some y in Y. But then the> subsequence converges to two distinct points, y and y, and this isimpossible,> since X is Hausdorff.>> There is an example of a limit point compact space that isnt compact inmy> Munkres book which is :>> Let Y consist of two points and give Y the topology consisting of Y andthe> empty set. Then X = Z_+ x Y is limit point compact but not compact.(Z_+> is the positive integers).>> Can I use this to show a counterexample?>> No. Your space is obviously non-Hausforff.> Jose Carlos Santos Is a limit point compact subspace of a Hausdorff space necessarilyclosed?>>I suppose that a limit point compact subspace is a subspace such that>>each sequence has a convergent subsequence. The usual expression for>>that is sequencially compact.> The denition of a limit point compact space is such that every innite> subset of that space has a limit point. Sequential compactness is only an> equivalent denition when the space is metrizable.OK. But since, obviously sequentially compact countably compact limit point compactmy previous counter-example is still a counter-example.Jose Carlos Santos > Is a limit point compact subspace of a Hausdorff space necessarilyclosed?>> Whats a limit point compact space?>A space is said to be limit point compact if every innite subset of thespace has a limit point.> Let Y consist of two points and give Y the topology consisting of Y andthe> empty set. Then X = Z_+ x Y is limit point compact but not compact.(Z_+> is the positive integers).>> Can I use this to show a counterexample? I guess the question is does Xsit> inside of a Hausdorff space making X open? I dont think it doesbecause X> itself is not Hausdorff since the open sets consist of unions of {n} x Yand> thus if Y = {a,b}, then 1 x a and 1 x b do not have disjointneighborhoods.>> No, subspaces of Hausdorff spaces are Hausdorff. Its not much easier to dene a method to get a random (and in this> context implicitly of a uniform distribution) real number from the> unit interval, but the probability of it being less than one half is> one half.In this case you appear to be dening the probability of choosing a number in any given subinterval of the unit interval as being the length of that subinterval. It can be shown that such a measure satises the necessary properties of probability functions, at least for intervals and nite unions of them. For anything else, there are problems to deal with before you can speak of probability as casually as you do. I dont have a method to select a random integer uniformly, but for> any such method that there ever could be the probability of its result> being an even integer is one half.If you mean a method for choosing one object from a countably innite set in such a way that every member of that set has an equal chance of being the one chosen, it is quite impossible, so your probability of its being an even integer is mathematically undened. =The ARC Centre of Excellence for Mathematics and Statistics ofComplex Systems (MASCOS) announces the availability of a ResearchFellowship at the University of Queensland within the Disciplineof Mathematics.The successful applicant will work closely with Dr Phil Pollett,Director (Queensland) of MASCOS, and will be associated with oneor more of the following projects: o The Construction and Classication of Markov Chains o Stochastic Models for Complex Biological Systems o Strong and Geometric Ergodicity in Markov ChainsAn appointment will be made at the level of Postdoctoral Fellow,Research Fellow or Senior Research Fellow (depending on quali-cations and experience). Applicants should hold a PhD in any areaof Stochastic Processes and have a demonstrated record of re-search achievement. An appointment at the level of Research Fel-low and Senior Research Fellow will require a substantial body ofpublished work, and a proven capacity for self-directed research.Further details: http://www.maths.uq.edu.au/~pkp/Fellowship.html______________ __________________________________________________Dr Philip K Pollett, Director (Qld) ARC Centre of Excellence forMathematics and Statistics of Complex Systems www.complex.org.au == Let us say we have a loop of chain (or we have a necklace) of m^2links/beads, each link/bead colored with one of n colors.Now, we take a m-by-m grid, over which we can place the chain so thateach square contains exactly one link.(m is even.)How many ways can we expect to be able place the chain so that nosimilar colors are in any immediately adjacent (up/left/down/right)squares?(Of course, the exact number varies according to how the links arecolored. I guess I am just wishing for some analysis on this. Perhapsthe number is exactly determined or approximated asymptotically basedon some statistic of how the chain is colored.)And what would the number be in the range of, if the chain need not bea loop?(m may be either odd or even, in this case.)this question was directly inspired by this puzzle from way &rnum=13&prev=I wonder if I can get any idea if any such maze has multiple solutions(after rotation/reection), and if so, what would the magnitude ofthis number of solutions >>James Harris posted a new version of his proof of a core >error on October 12. He made a simple algebra mistake>which he has since acknowledged. >> The interesting thing about this is that, when the algebra>mistake is corrected, it leads immediately to a proof that>him main conclusions are wrong.>>...>>JSH will ignore your post.>Gib,>> I dont think he has ignored it. However he has none >too courageously avoided replying to it. >>...>>The distinction is too subtle for me ;-)>>GibGib, Oh, I doubt that. Avoid and ignore are quite > distinct. You might avoid a polar bear if one showed up> in your neighborhood, but you probably wouldnt ignore > it. OK, good example :-) On the other hand, if Im trying to get your attention by, say, standing next to you and uttering your name, and you do not respond, we would commonly say that you were ignoring me.GibGib =Gib Bogle frontthe shed door: ^ > I dont think he has ignored it. However he has none ^ >too courageously avoided replying to it. ^ >>The distinction is too subtle for me ;-)^ > Oh, I doubt that. Avoid and ignore are quite ^ > distinct. You might avoid a polar bear if one showed up^ > in your neighborhood, but you probably wouldnt ignore ^ > it. ^ OK, good example :-) On the other hand, if Im trying to get your ^ attention by, say, standing next to you and uttering your name, and you ^ do not respond, we would commonly say that you were ignoring me.Both true, and not inconsistent with each other. That is because ofthe distinction Nora has unaccountably introduced between thedistinction between avoid and ignore (as per the polar bearexample) and the distinction between avoid replying to andignore (as per the original JSH example). If a polar bear showed upin your neighbourhood, you would be well advised not to ignore it; butif it spoke to you, you would be very well advised indeed not to avoidreplying to it.Andy--Hell! - dont worry about old raving Dave Ullrich ...Basically hes a sociopath who cant see a red ragwithout regarding it as a personal insult.Bill Taylor, sci.math =Evaluate the summation 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1 ??? Evaluate the summation 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1 ???Did the instructor specify that you were supposed to post _all_ thehomework questions to sci.math? (And are you going to haveinternet access when you take the nal exam?) Just curious...************************David C. Ullrich == Evaluate the summation 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1 ???Did the instructor specify that you were supposed to post _all_ the> homework questions to sci.math? (And are you going to have> internet access when you take the nal exam?) Just curious...> ************************David C. UllrichAsshole im just asking for some help what are forum for ! Asshole im just asking for some help what are forum for !Maybe thats what *you* should be asking. What are the forums for?And anyone that was going to do your homework problems for you probablywont now that youve called us all assholes.Doug Evaluate the summation 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1 ???Did the instructor specify that you were supposed to post _all_ the> homework questions to sci.math? (And are you going to have> internet access when you take the nal exam?) Just curious...> ************************David C. UllrichYes exactly Evaluate the summation 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1 ???You might mean 1/1+2/2+3/4+...+n/2^(n-1) .The answer is 4 - (2 + n)/2^(n-1) .Can you explain to the instructor how you got it? Evaluate the summation 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1 ???You might mean 1/1+2/2+3/4+...+n/2^(n-1) .The answer is 4 - (2 + n)/2^(n-1) .Can you explain to the instructor how you got it?> I try it but i cant get the same answer!! Evaluate the summation 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1 ??? =Evaluate the innite sum 1/1 + 2/2 + 3/4 + 4/8 + ... .????? Evaluate the innite sum 1/1 + 2/2 + 3/4 + 4/8 + ... .?????I would have, but not if you are going to keep posting the same messageover and over again. Sorry.Doug Evaluate the innite sum 1/1 + 2/2 + 3/4 + 4/8 + ... .?????Draw a rectangle of 2*1, width 2 and height 1. Over it, aligned to right,draw a rectangle of 1*1 (yes, a square is a rectangle). Over it, draw otherrectangle of (1/2)*1, aligned to right, over it other of (1/4)*1and so on...The sum of the areas of all of them is ...?Now, continue to down the left vertical sides of the rectangles until thebasis of the rst rectangle, and sum the areas, gouping that are in thesame vertical:1 + 2(1/2) + 3(1/4) + 4(1/8) + ...that is your series.That is the method follow by Oresme (1350 a.c.) to sum that series and othersimilars.-- Ignacio Larrosa Ca.96estroA Coru.96a (Espa.96a)ilarrosaQUITARMAYUSCULAS@mundo-r.com Evaluate the innite sum 1/1 + 2/2 + 3/4 + 4/8 + ... .?????Whats in it for me?particular for x = 1/2. =I am certain this is well-known, but it does not look familiar. (It ismost probably known in a simpler form.)Let us say we have a polygon P which is inscribed in a unit circle(each vertex of P coincides with the circle).P is an n-gon which has the known interior angles{a(1),a(2),a(3),...a(n)}.(So, sum{k=1 to n} a(k) = (n-2) pi radians)So, am I right in assuming that the area of P is:sum{k=1 to n} cos(b(k)) sin(b(k)),where b(k) =(1/2) sum{j=1 to n} a(j) c(j,k),where c(j,k) = (-1)^(j+k) if j <= k;and c(j,k) = (-1)^(1+j+k) if j > k.A related question: If a(k) = 2 pi (1 - 2/(k+r)) radians, for k <= n-1,and a(n) = (n-2) pi - sum{k=1 to n-1} a(k), so that the polygoncontains the angles, one angle per m-gon, of the regular (1+r)-gon tothe regular (n+r-1)-gon, plus one extra angle (to make things workout);then, what is this polygon named? Harmonic Let us say we have a polygon P which is inscribed in a unit circle> (each vertex of P coincides with the circle).> P is an n-gon which has the known interior angles> {a(1),a(2),a(3),...a(n)}.> (So, sum{k=1 to n} a(k) = (n-2) pi radians)So, am I right in assuming that the area of P is:sum{k=1 to n} cos(b(k)) sin(b(k)),where b(k) =(1/2) sum{j=1 to n} a(j) c(j,k),where c(j,k) = (-1)^(j+k) if j <= k;> and c(j,k) = (-1)^(1+j+k) if j > k.> I do not think this is correct, but I may be mistaken. I took thecase that P is a square. Then a(1) = a(2) = a(3) = a(4) = pi / 2.I also got that b(1) = b(3) = 0 and b(2) = b(4) = pi / 2For every b(k), either sin(b(k)) = 0 or cos(b(k)) = 0 sosum {k=1 to n} cos(b(k)) sin(b(k)) = 0Your formulation looks very interesting, though. Id like very muchto see your reasoning behind it. Its quite possible that it can becorrected.In any case, I think I know a slightly easier formulation of the areaof P(1/2) sum{k=1 to n} cos(pi - a(k)/2 + a(k+1)/2 )where we take a(n+1) = a(1).In case youre wondering, this is a sum over the areas of thetriangles formed by the middle of the circle and each one of the sidesof the polygon P.A related question: If a(k) = 2 pi (1 - 2/(k+r)) radians, for k <= n-1> ,> and a(n) = (n-2) pi - sum{k=1 to n-1} a(k), so that the polygon> contains the angles, one angle per m-gon, of the regular (1+r)-gon to> the regular (n+r-1)-gon, plus one extra angle (to make things work> out);You must choose r rather carefully so that sum{k=1 to n-1} a(k) < (n-2) 2 pisum_k (1-2/(k+r)) < (n-2)2 > sum_k 2 / (k+r)1 > sum_k 1 / (k+r)> then, what is this polygon named? Harmonic Polygon??Never heard of it. I wouldnt call it the Harmonic Polygon because itonly has a nite number of angles. Why are you interested? Perhapsthe application will suggest a =Well, the below MAY be true for all integers n, n >= 3, but this wouldbe a coincidence.For I only actually found, if I did not err even in this regard, thatthe below is true (true) for ODD does not look familiar. (It is> most probably known in a simpler form.)> Let us say we have a polygon P which is inscribed in a unit circle> (each vertex of P coincides with the circle).> P is an n-gon which has the known interior angles> {a(1),a(2),a(3),...a(n)}.> (So, sum{k=1 to n} a(k) = (n-2) pi radians)So, am I right in assuming that the area of P is:sum{k=1 to n} cos(b(k)) sin(b(k)),where b(k) =(1/2) sum{j=1 to n} a(j) c(j,k),where c(j,k) = (-1)^(j+k) if j <= k;> and c(j,k) = (-1)^(1+j+k) if j > k.> A related question: If a(k) = 2 pi (1 - 2/(k+r)) radians, for k <= n-1> ,> and a(n) = (n-2) pi - sum{k=1 to n-1} a(k), so that the polygon> contains the angles, one angle per m-gon, of the regular (1+r)-gon to> the regular (n+r-1)-gon, plus one extra angle (to make things work> out);> then, what is this polygon 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2n-1.> AND> 1/1 + 2/2 + 3/4 + 4/8 + ...> Comment on notation:> By usual newsnet interpretation of math symbols,> 1/2n-1 reduces to -1/2.> Does your n/2n-1 mean the same as n/2^(n-1),> where ^ means raised to the power of, and the parentheses are > necessary?> Re the problem:> Note f_n(x) = 1 + x + x^2 + ...+ x^n = (1-x^(n+1))/(1-n)> and g(x) = 1 + x + x^2 + ... = 1/(1-x) near x = 1/2.> Their derivatives with respect to x evaluated at x = 1/2 are> what you want.> I have to calculate using the geometric formula for sequences...> and n/2n-1 is not n/2^(n-1) its n/2n-1In the absence of any parentheses, multiplications and divisions are > always given priority over additions and subtractions, soeither n/2n-1 = ((n/2)*n) - 1 = n^2/2 - 1, or n/2n-1 = (n/(2*n)) - 1 = -1/2, and in neither case does it t into your sequence of> 1 + 1/2 + 1/4 + 1/8 + ... 1/2^0 + 1/2^2 + 1/2^2 + 1/2^3 + ...> by ane stretch of the imaginationSorry the sequences are separated1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1.and 1/1 + 2/2 + 3/4 + 4/8 + ...are two separated sequences!! 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2n-1.> AND> 1/1 + 2/2 + 3/4 + 4/8 + ...> Comment on notation: By usual newsnet interpretation of math symbols,> 1/2n-1 reduces to -1/2.> Does your n/2n-1 mean the same as n/2^(n-1),> where ^ means raised to the power of, and the parentheses are > necessary?> Re the problem:> Note f_n(x) = 1 + x + x^2 + ...+ x^n = (1-x^(n+1))/(1-n)> and g(x) = 1 + x + x^2 + ... = 1/(1-x) near x = 1/2.> Their derivatives with respect to x evaluated at x = 1/2 are what you want.> I have to calculate using the geometric formula for sequences...> and n/2n-1 is not n/2^(n-1) its n/2n-1> In the absence of any parentheses, multiplications and divisions are > always given priority over additions and subtractions, so> either n/2n-1 = ((n/2)*n) - 1 = n^2/2 - 1, > or n/2n-1 = (n/(2*n)) - 1 = -1/2, > and in neither case does it t into your sequence of> 1 + 1/2 + 1/4 + 1/8 + ... 1/2^0 + 1/2^2 + 1/2^2 + 1/2^3 + ...> by any stretch of the imagination> Sorry the sequences are separated> 1/1 + 2/2 + 3/4 + 4/8 + ... + n/2^n-1.and > 1/1 + 2/2 + 3/4 + 4/8 + ...are two separated sequences!!The rst terminates and the second does not, but the second should contain the rst, as it contains all of the terms of the rst and more besides.The last term of the rst sequence is still not correctly denoted.It should be n/2^(n-1) if n-1 is supposed to be the exponent and 2 the base of a power.The point is that the series whose general term is k*x^(k-1), with x = 1/2, is related to the series whose general term is x^k by being, term by term, the derivative of x^k with respect to x.And 1 + x + x^2 + ... + x^n = (1-x^(n+1))/(1-x), unless x = 1,and1 + x + x^2 + ... = 1/(1-x), for x^2 < 1.The sercret of solving the problem is in these hints. =participant,> but this link has the stuff:>> http://www.math.dartmouth.edu/~euler/for, for sure.-- Karl M. Bunday Christ has set us free. Galatians 5:1Learn in Freedom (TM) http://learninfreedom.org/ The number of ways of distributing m identical balls into n urns is> C(m+n-1,n-1), where C(n,r) denotes n choose r.> Could somebody outline a proof for this?The proof I recall is hard to outline without giving it away; theres alarge aha! factor. It involves taking m red balls and n-1 green balls,and lining them up. Notice how the green balls divide the red balls intogroups...> Also, is there a more general> result where we have conditions like p_i <= x_i <= q_i, and 0 < p_i,q_i <=m, that is the number of balls in the i^{th} urn has> arbitrary lower and upper bounds.There may be, but I dont see a way to generalize the proof Ive suggested.Brian I really need some help on this question. Ive not been studying matrices> for more than a couple of weeks and I am getting in a muddle. Let lamda = L and let epsilon = e. Im is the identity matrixThe elementary matrices E(r,s;L) and P(r,s) are dened as follows:E(r,s;L) = Im + Le(r,s)P(r,s) = Im - e(r,r) - e(s,s) + e(r,s) +e(s,r)Where r does not = se(r,s)e(u,t) = { e(r,t) s=u and 0 where s doesnt = uIf the indices i, r, s are all different nd the elementary matrix X such> thatP(i,r)E(r,s;L) = XP(i,r)Your notation makes no sense to me - sorry. Ill assume these are theusual elementary matrices:E(r, s; L) is the identity matrix I with its s-th row relaced by thesum of the s-th row of I and L times the r-th row of I. ConsequentlyE(r, s; L)*A is A with the s-th row of A replaced by the sum of thes-th row of A and L times the r-th row of A.P(r, s) is I with the r-th and s-th rows interchanged. So P(r, s)*A isA with its r-th and s-th rows interchanged.Now, note P(i, r)*P(i, r) = I so you have no choice about X:X = X*P(i, r)*P(i. r) = P(i, r)*E(r, s; L)*P(i, r).So, the question is whether P(i, r)*E(r, s; L)*P(i, r) is elementary. [ Yes, it is E(i, s; L) providing neither i nor r is equal to s ]-- Paul SperryColumbia, SC (USA) =i have the following problem: i need tofind efciently, in linear time,the longest contiguoussubsequence in a sequence of ones and zeroes in which number of 0s - numberof 1sis 2 mod 5. The only algorithm i can think of is is quadratically timerelated to the size of thesequence. i have the following problem: i need tofind efciently, in linear time,>the longest contiguous>subsequence in a sequence of ones and zeroes in which number of 0s - number>of 1s>is 2 mod 5. The only algorithm i can think of is is quadratically time>related to the size of the>sequence.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 > I was wondering if I could get some help on this problem.>> We know that multiplication of integers is commutative; i.e. ab=ba for> all pairs of integers a and b. Prove that, for every natural number n,> the product of n integers is independant of the order of the factors.>Induct over n using your axiom (ab=ba) as your base case > I was wondering if I could get some help on this problem.>> We know that multiplication of integers is commutative; i.e. ab=ba for> all pairs of integers a and b. Prove that, for every natural number n,> the product of n integers is independant of the order of the factors.>Induct over n using your axiom (ab=ba) as your base caseAnd assuming complete associativity of multiplication! =Let phi=(1+sqrt(5))/2 and Q(X)= X^9 - (4*phi^2)X^7 + a(3)X^6 + ... +a(9) .It is known that all roots x_1,x_2,...,x_9 of Q(X) are real, andmoreover that Q(X) > 0 for all x in ( phi/3 , infty) .Its possible tofind the roots of Q(X) ? How ? look athttp://www.library.cornell.edu/nr/bookcpdf/c9-5.pdfp 375Roland> Let phi=(1+sqrt(5))/2 and> Q(X)= X^9 - (4*phi^2)X^7 + a(3)X^6 + ... +a(9) .> It is known that all roots x_1,x_2,...,x_9 of Q(X) are real, and> moreover that Q(X) > 0 for all x in ( phi/3 , infty) .> Its possible to nd the roots of Q(X) ? How ?> sum 1/1 + 2/2 + 3/4 + 4/8 + ... .?????>Okay, I evaluated it... now what should I do?adam >Evaluate the innite sum 1/1 + 2/2 + 3/4 + 4/8 + ... .?????>Okay, I evaluated it... now what should I do?adam >Evaluate the innite sum 1/1 + 2/2 + 3/4 + 4/8 + ... .?????>Okay, I evaluated it... now what should I do?adami WANT TO KNOW HOW???? i WANT TO KNOW HOW????Fantastic. Doug You can deduce easily that must be 4 inection points: before the maximum,> between maximum and minimum and after the minimum.... the root x = - 1, ..> the roots 2 +/- sqrt(3); May be a typo ... 3 inection points. __ Homework problem ? > You can deduce easily that must be 4 inection points: before the>> maximum, between maximum and minimum and after the minimum.... the>> root x = - 1, .. the roots 2 +/- sqrt(3);>> May be a typo ... 3 inection points. __ Homework problem ?Yes, it is a typo. There is three inection points.-- Ignacio Larrosa Ca.96estroA Coru.96a (Espa.96a)ilarrosaQUITARMAYUSCULAS@mundo-r.com I have 2 quick questions...> 1. Sketch the graph of the following function showing vertical and> horizontal asymptotes and relative extrema. Label your x-axis in> terms of a and your y-axis in terms of 1/a.> f(x)=(a-x)/(x^2+a^2) where a is a constant, a greater than 0.> I canfind out the 2 stationary points, the HA, and that their are no> VAs. I dont get how tofind other points to make that graphs> however, or inection points etc.2.Sketch the graph of the following:>> I canfind that its an odd function. The VA is x=-2. I cant gure out the relative> extrema or IPs or HA for some reason though.Scott Eliasonthe function in the second question should be... f(x) = (5(x^2 + 6)^(.5))> ----------------> x+2sorry about the mistake.scott eliason > 2.Sketch the graph of the following:>> I canfind that its an odd function. The VA is x=-2. I cant>> gure out the relative>> extrema or IPs or HA for some reason though.>> Scott Eliason>> the function in the second question should be...>> f(x) = (5(x^2 + 6)^(.5))>> ---------------->> x+2> sorry about the mistake.> scott eliasonAs I said before, that isnt an odd function, becaus f(-x) =/= f(x).In order to sketch the graph:Study the domain and vertical asymptotes or other discontinuities. Alsohorizontals or oblicues. Study intersections of the graph with axis andasymptotes (onlu HA and OA, no VA, of course). With that, place the graph atthe correct side of axis and asymptotes in each interval.Get the rst derivative. Get the critical points with f(x) = 0. Studyintervals of increasing and decreasing with the sign of the derivative,using critical and discontinuity points. This says you if the criticalpoints are maximum or minimums.The same with second derivative: solve f(x) = 0, study sign(f(x)), asbefore with f(x). With that, determine what of the roots of f(x) areinection points.Sketch all result as soon as you determine it. The graph will be sketchingalone ..Ignacio Larrosa Ca.96estroA Coru.96a (Espa.96a)ilarrosaQUITARMAYUSCULAS@mundo-r.com =Let A be the real matrix / 0 a b c A= / a 0 d e b d 0 f / c e f 0 / where a^2+b^2+c^2+d^2+e^2+f^2 = 6 .Consider that r_1 =< r_2 =< r_3 =< r_4 are eigenvalues of A.It is known that r_4= 10. Its true that all eigenvalues are integer numbers ?If A is non-singular, which is the inverse matrix A^{-1} ? > b d 0 f / > c e f 0 / >where a^2+b^2+c^2+d^2+e^2+f^2 = 6 .>Consider that r_1 =< r_2 =< r_3 =< r_4 are eigenvalues of A.>It is known that r_4= 10. >Its true that all eigenvalues are integer numbers ?>If A is non-singular, which is the inverse matrix A^{-1} ?> ==It cant happen that r_4 = 10. The characteristic polynomial ofA is t^4 - (a^2+b^2+...+f^2) t^2 + c1 t + c0 for some c1 and c0.So youd need r1 + r2 + r3 + r4 = 0 and -6 = r1 r2 + r1 r3 + r1 r4 + r2 r3 + r2 r4 + r3 r4 = 1/2 ((r1 + r2 + r3 + r4)^2 - r1^2 - r2^2 - r3^2 - r4^2)i.e. r1^2 + r2^2 + r3^2 + r4^2 = 12. In particular r4 <= 2 sqrt(3). Suppose we remove the requirement r_4=10. The only ways to get 12 as a sum of four squares are 1^2 + 1^2 + 1^2 + 3^2 and 0^2 + 2^2 + 2^2 + 2^2, so the only integer solutions tor1+r2+r3+r4=0 and r1^2+r2^2+r3^2+r4^2=12 with r1<=r2<=r3<=r4are [-1,-1,-1,3] and [-3,1,1,1]. It is possible to get theseeigenvalues, e.g. with a=b=c=d=e=f=1 or a=b=c=d=e=f=-1 respectively.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 Let A be the real matrix> / 0 a b c > A= / a 0 d e > b d 0 f / > c e f 0 / >where a^2+b^2+c^2+d^2+e^2+f^2 = 6 .>Consider that r_1 =< r_2 =< r_3 =< r_4 are eigenvalues of A.>It is known that r_4= 10. >Its true that all eigenvalues are integer numbers ?>If A is non-singular, which is the inverse matrix A^{-1} ?> ==It cant happen that r_4 = 10. The characteristic polynomial of> A is t^4 - (a^2+b^2+...+f^2) t^2 + c1 t + c0 for some c1 and c0.> So youd need r1 + r2 + r3 + r4 = 0 and > -6 = r1 r2 + r1 r3 + r1 r4 + r2 r3 + r2 r4 + r3 r4 > = 1/2 ((r1 + r2 + r3 + r4)^2 - r1^2 - r2^2 - r3^2 - r4^2)> i.e. r1^2 + r2^2 + r3^2 + r4^2 = 12. In particular > r4 <= 2 sqrt(3). Suppose we remove the requirement r_4=10. The only ways to > get 12 as a sum of four squares are 1^2 + 1^2 + 1^2 + 3^2 and > 0^2 + 2^2 + 2^2 + 2^2, so the only integer solutions to> r1+r2+r3+r4=0 and r1^2+r2^2+r3^2+r4^2=12 with r1<=r2<=r3<=r4> are [-1,-1,-1,3] and [-3,1,1,1]. It is possible to get these> eigenvalues, e.g. with a=b=c=d=e=f=1 or a=b=c=d=e=f=-1 respectively.Robert Israel israel@math.ubc.ca> Department of Mathematics http://www.math.ubc.ca/~israel > University of British Columbia > Vancouver, BC, Canada V6T 1Z2Robert Israel ,According to your important remarks, conditioninstead of r_4=10 we must have ,e.g. x_4=3 . Let A be the real matrix> / 0 a b c > A= / a 0 d e > b d 0 f / > c e f 0 / > where a^2+b^2+c^2+d^2+e^2+f^2 = 6 .> Consider that r_1 =< r_2 =< r_3 =< r_4 are eigenvalues of A.> It is known that r_4= 10. > Its true that all eigenvalues are integer numbers ?> If A is non-singular, which is the inverse matrix A^{-1} ?Matlabs Maple engine says this:A =[ 0, a, b, c][ a, 0, d, e][ b, d, 0, f][ c, e, f, 0]det(A) =a^2*f^2-2*a*d*c*f-2*a*e*b*f+b^2*e^2-2*b*e*c*d+c^2*d^2The inverse of A was a huge unreadable thing involvingfractions with the expression for det(A) in the denominator.This is more readable:det(A)*inv(A) =[ 2*d*e*f, f*(a*f-b*e-c*d), -e*(a*f-b*e+c*d), -d*(a*f+b*e-c*d)][ f*(a*f-b*e-c*d), 2*b*c*f, -c*(a*f+b*e-c*d), -b*(a*f-b*e+c*d)][ -e*(a*f-b*e+c*d), -c*(a*f+b*e-c*d), 2*a*c*e, a*(a*f-b*e-c*d)][ -d*(a*f+b*e-c*d), -b*(a*f-b*e+c*d), approve@localhost) by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id h9G24cL25908; = There was pretty hard to harm this conjecturein some more easy way as it did lately prof. A. Wiles ... Anyhow some special selection of FLT rules andproperties seems to extend some procedure anddismiss some unknown value just to 0 ... What is already true once so called trivialsolution exists for one of values considered tobe 0 but so on not the natural value and notthe sort of intigers denied rst by Fermat... Details very soon once the cheeck procedurewill be nished with my friend prof. W.Heiermann Be patient, Yours Ro = There was pretty hard to harm this conjecture> in some more easy way as it did lately prof. A. Wiles ...> Anyhow some special selection of FLT rules and> properties seems to extend some procedure and> dismiss some unknown value just to 0 ...> What is already true once so called trivial> solution exists for one of values considered to> be 0 but so on not the natural value and not> the sort of intigers denied rst by Fermat...> Details very soon once the cheeck procedure> will be nished with my friend prof. W.Heiermann> Be patient, Yours RoWill the prof be checking the grammar and spelling as wellas the maths? Just wondering. = > There was pretty hard to harm this conjecture > in some more easy way as it did lately prof. A. Wiles ... > Anyhow some special selection of FLT rules and > properties seems to extend some procedure and > dismiss some unknown value just to 0 ... > What is already true once so called trivial > solution exists for one of values considered to > be 0 but so on not the natural value and not > the sort of intigers denied rst by Fermat... > Details very soon once the cheeck procedure > will be nished with my friend prof. W.Heiermann > Be patient, > Will the prof be checking the grammar and spelling as well > as the maths? Just wondering.I was wondering in what language the proof would be written.-- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131home: bovenover 215, 1025 (from approve@localhost) by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id h9G3kTe32625; of two intersecting circles? If> there are two circles with a radius of 30 feet and the center of the two> circles were 50 feet apart from each other, then there would be 10 foot> of overlap. What would the surface area of these circles be?You asked this question earlier in the thread overlapping circles.The answer I gave you there for the area of the overlap wasUse formula (12) at.If this answer is not adequate for your purpose, please tell us why.David =Chris> How do you calculate the surface area of two intersecting circles?> If there are two circles with a radius of 30 feet and the center of thetwo circles were 50 feet apart > from each other, then there would be 10foot of overlap. What would the surface area of> these circles be? I got as far as A=pi*r^2.> For the two circles in this question that would be 5,654 Sq Ft.> So to answer this question, it would be 5,654 Sq Ft minus overlap area?> How do you calculate the overlap area?The overlap consists of two chunks (lunae, I think theyre called) each ofwhich is in the shape of a pie slice minus a triangle. See it now?LH =Where could Ifind a proof for following:f : R^n -> R+ If f is strictly convex in a convex region Dthen the Newtons iteration x_k+1 = x_k - inv(f(x_k)) f(x_k)^Tconverges to the minimum of f from any starting point in D.Ive been trying to apply various known convergence conditions, but they seem a bit overkill for this and I havent reallybeen able to use the convexity of f for anything.Is this too trivial a result or am I mistaken in my assumption? Where could Ifind a proof for following:>>f : R^n -> R+ >If f is strictly convex in a convex region D>then the Newtons iteration>> x_k+1 = x_k - inv(f(x_k)) f(x_k)^T>>converges to the minimum of f from any starting point in D.You cantfind a proof of this anywhere, because its not true.To start, f need not _have_ a minimum in D. But even if itdoes Newtons method need not converge to it. This isshown by a standard example:Lets take n = 1 for simplicity. Youre using Newton tofindthe zero of g = f. Saying f is strictly convex says that gis strictly increasing. Concoct a strictly increasing functiong such that g(-1) = -1, g(1) = 1, g(-1) = g(1) = 1/2. Thenif you apply Newtons method starting at x = 1 you getthe sequence 1, -1, 1, -1, ..., which does not convergeto the zero of g.>Ive been trying to apply various known convergence conditions, >but they seem a bit overkill for this and I havent really>been able to use the convexity of f for anything.>Is this too trivial a result or am I mistaken in my >assumption? >************************David C. Ullrich Let p_k be the kth prime number.> i.e. P_1=2, p_2=3, p_3=5,....Then is it true that (p_n + p_1)/2 >= (p_1+p_2+...+p_n)/n for all natural > number n?Probably. Its certainly true for n up to 10000. And numerically it seems the difference between the two sides is asymptotic to cn for someconstant c, 0.25 < c < 0.3.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 >>It could be a constant vector, but my guess is that the equation is>>actuallyr = -k r/|r|^3>>Well of course that was my guess as well, which is why I>didnt decide right away that k was a constant vector...Well, of course it has many closed-form solutions. Its>>not possible to express the general solution in closed>>form, is it?>> Not as far as I know (for r as a function of last 300 years> or so, so it would be pretty remarkable if you got an> answer in a newsgroup in a couple of days.>> - RandyIm a hoping and optimist boy!! :-)Marco There is no need for more food. People go hungry not because there is> not enough food, but because they do not have enough money to buy the> food of which there is plenty.Countries like USA keep the price of food high to protect their ownagriculture. If the price of food was lower, the less developed countrieswould be able to compete on the market and thus produce more food also fortheir own people. There is no need for more food. People go hungry not because there is> not enough food, but because they do not have enough money to buy the> food of which there is plenty.Countries like USA keep the price of food high to protect their own> agriculture. If the price of food was lower, the less developed countries> would be able to compete on the market and thus produce more food also for> their own people.Food does not reach people who need it for logistic reasons, not becauseof any lack of money or any conspiracy on the part of developed nations.The nations that have the fastest growing populations also tend to havethe least advanced agriculture.The solution is not to produce and distribute ever increasing amounts offood; it is to instead reduce overpopulation. The world populationcannot increase innitely, and the larger it gets, the lower thestandard of living will be for everyone. It makes more sense tomaintain smaller populations with higher standards of living. Developednations tend naturally in this direction, in most cases. Developingnations tend to have unacceptably natural rates of increase, and so theytend to have periodic famines and very low standards of living.-- There is no need for more food. People go hungry not because there is> not enough food, but because they do not have enough money to buy the> food of which there is plenty.It really has nothing to due with money. Famines are caused due to lackof the political infrastructure needed to distribute the food. A fewyears ago, a Nobel prize in Economics was awarded for research in thisarea - there has never been a famine in a democratic country, independentof monetary considerations.> Countries like USA keep the price of food high to protect their own> agriculture. If the price of food was lower, the less developed countries> would be able to compete on the market and thus produce more food also for> their own people.Thats somehwat true. The USA pays more for sugar than any other nationowing to our tariffs. Your implication is that developing nations somehowneed to compete on the agricultural world market. Thats less of a concernthan producing what their nation requires. Keep in mind that the privateorganizations (e.g., CARE) export raw agricultural products to developingnations so they can monitize the aid. That is, some country might receivetons of soybeans so they can resell it on the open market for hard cash.Food does not reach people who need it for logistic reasons, not because> of any lack of money or any conspiracy on the part of developed nations.> The nations that have the fastest growing populations also tend to have> the least advanced agriculture.I am unaware of any evidence suggesting that the fastest growing populationsare the least advanced in terms of agriculture. What are some examples andwhat implications do you intend to draw from this assertion?The solution is not to produce and distribute ever increasing amounts of> food; it is to instead reduce overpopulation. The world population> cannot increase innitely, and the larger it gets, the lower the> standard of living will be for everyone. It makes more sense to> maintain smaller populations with higher standards of living. Developed> nations tend naturally in this direction, in most cases. Developing> nations tend to have unacceptably natural rates of increase, and so they> tend to have periodic famines and very low standards of living.You seem to view the world as some nite set of resources ever taxed bya growing population. Yet we continue to discover new resources - not necessarily agricultural or natural (i.e., oil), but more tailored to thepresent economy. The economic history of the US for example, exhibits anincreasing standard of living despite its increasing population.Can you reasonably say that 100 years ago, the US had a better standardof living than we have today? The population was lower after all. I am unaware of any evidence suggesting that the fastest growing populations> are the least advanced in terms of agriculture. What are some examples and> what implications do you intend to draw from this assertion?Subsaharan Africa comes to mind.The implication is that the same stupidity that prevents a country frombeing skilled in agriculture also prevents it from controlling its ownpopulation. Usually things like disease will maintain equilibrium, butwhen more advanced countries help, the diseases go down, but the rateof natural increase goes up, and the production of food doesnt change.So eventually lots of people being to starve. Eventually starvationrestores equilibrium, at least temporarily, but its not very elegant.> You seem to view the world as some nite set of resources ever taxed by> a growing population.Yes.> Yet we continue to discover new resources - not necessarily agricultural> or natural (i.e., oil), but more tailored to the present economy.That will not continue forever, and its best not to increase thepopulation until you are sure that you can support the increase.> The economic history of the US for example, exhibits an> increasing standard of living despite its increasing population.The United States has an educated population (including women, which iscritical).> Can you reasonably say that 100 years ago, the US had a better standard> of living than we have today? The population was lower after all.Technology has outpaced population growth in the U.S. That wontcontinue forever, nor is it transferable to other countries.-- =<...>> The implication is that the same stupidity that prevents a country from> being skilled in agriculture also prevents it from controlling its own> population.Wrong. In many underdeveloped countries, having many children is theonly possible insurance for old age support, and that keeps the birthrate high. Thats why education helps. A good profession provides enoughsupport even with less children.-- Lassi In many underdeveloped countries, having many children is the> only possible insurance for old age support, and that keeps the birth> rate high.Thats true when mortality is high. But as mortality is reduced(usually with the help of outsiders with technology), that same highbirth rate rapidly increases the population and exhausts the food.> Thats why education helps. A good profession provides enough> support even with less children.And women who are educated are less likely to be willing to spend theirlives reproducing as well.-- You seem to view the world as some nite set of resources ever taxed by>a growing population. Yet we continue to discover new resources - not >necessarily agricultural or natural (i.e., oil), but more tailored to the>present economy. The economic history of the US for example, exhibits an>increasing standard of living despite its increasing population.>Can you reasonably say that 100 years ago, the US had a better standard>of living than we have today? The population was lower after all.The world *is* a nite set of resources...although improvements in technology increase the usefulness and valueof those resources.Hence, population can cause problems if it increases faster thantechnology keeps up... and, given that there do exist people who havelow standards of living, apparently population does tend to increasefaster than improvements in technology in most places.Unfortunately, we dont have any more empty continents with whichother people could get the jump on the game the way the Europeaninhabitants of the New World did.John Savardhttp://home.ecn.ab.ca/~jsavard/index.html =Were getting pretty far from math or crypt...>> There is no need for more food. People go hungry not because there is> not enough food, but because they do not have enough money to buy the> food of which there is plenty.One good way to keep the famines happening is to send food for free.Local producers go bust, and the famines keep on repeating...> The solution is not to produce and distribute ever increasing amounts of> food; it is to instead reduce overpopulation.The best known way to reduce birth rate is to teach women to read. Thesocial impact is enormous.-- Lassi The best known way to reduce birth rate is to teach women to read. The> social impact is enormous.Agreed. Equal education for women in general reduces birth rates andimproves the standard of living. So does a good general level ofeducation for both sexes.-- = > The best known way to reduce birth rate is to teach women to read. Well, rst they will have to be considered as human beings, not ascommodity items, as they customarily are in Moslem countries and India.Yep, this is no politically correct, but it is nevertheless true. > Well, rst they will have to be considered as human beings, not as> commodity items, as they customarily are in Moslem countries and India.> Yep, this is no politically correct, but it is nevertheless true.And what do you think about how the women are considered in western(i.e. not majorily Moslem) countries, when you watch TV series,advertisings, magazines, etc ? Not much better, as they sometimes arerepresented as geese, often as sexual objects. If theyre not blondes withbig breasts, they are of no value.Still not politically correct, but also true.-- -----je crosspost sur fr rec moto pour ce triste mod.8ele dintol.8erance. [...]PS :D.8esol.8e mon logiciel de news ne permet pas les follow up et je nenchangerai certainement pas pour vous etre agr.8eable.-+- CC in Guide du Neuneu Usenet - Bien congurer son incomp.8etence -+- And what do you think about how the women are considered in western> (i.e. not majorily Moslem) countries, when you watch TV series,> advertisings, magazines, etc ? Not much better, as they sometimes are> represented as geese, often as sexual objects.Orders of magnitude better, actually. Ask any woman who has lived inboth societies.-- =Were getting pretty far from math or crypt...>> There is no need for more food. People go hungry not because there is> not enough food, but because they do not have enough money to buy the> food of which there is plenty.One good way to keep the famines happening is to send food for free.> Local producers go bust, and the famines keep on repeating...> The solution is not to produce and distribute ever increasing amounts of> food; it is to instead reduce overpopulation.The best known way to reduce birth rate is to teach women to read. The> social impact is enormous.With any luck, when the present pope dies his successor will be lessopposed to articial methods of birth control.-- G.C. With any luck, when the present pope dies his successor will be less> opposed to articial methods of birth control.You still have to teach and convince people to use it.-- With any luck, when the present pope dies his successor will be less> opposed to articial methods of birth control.You still have to teach and convince people to use it.Education is crucial in all matters relating to poverty I suspect.-- G.C. <3F8E898D.3C24B60F@ieee.orgasm-research.invalid> Were getting pretty far from math or crypt...>There is no need for more food. People go hungry not because there is>not enough food, but because they do not have enough money to buy the>food of which there is plenty. One good way to keep the famines happening is to send food for free.>> Local producers go bust, and the famines keep on repeating... The solution is not to produce and distribute ever increasing amounts of>> food; it is to instead reduce overpopulation.>> The best known way to reduce birth rate is to teach women to read. The>> social impact is enormous.>> With any luck, when the present pope dies his successor will be less> opposed to articial methods of birth control.The thread simply wasnt controversial enough for you? Why not bringup, say, skinhead abortions and gun control laws for baby seals?Take it elsewhere, willya?-- When I am grown to mans estateI shall be very proud and great,and tell the other girls and boysnot to meddle with my toys. --Robert Louis Stevenson There is no need for more food. People go hungry not because there is> not enough food, but because they do not have enough money to buy the> food of which there is plenty.Countries like USA keep the price of food high to protect their own> agriculture. If the price of food was lower, the less developed countries> would be able to compete on the market and thus produce more food also for> their own people.An ancient Chinese monarch was dining when he was toldthat the people didnt have enough rice to eat. Why dont they eat meat instead, the monarch exclaimed.M. K. Shen =-- KindlyKonrad------------------------------------------------- places;their souls be chased by demons in Gehenna from one room toanother for all eternity and more.Sleep - thing used by ineffective people as a substitute for coffeeAmbition - a poor excuse for not having enough sence to be lazy--------------------------------------------------- = Heres the existing function I have for rotating a 3D point (x,y,z) byangleX, Y, Z around point px,py,pz (its actually in a 3D vectorclass). Is there a simple way of adding 4D rotation to this? Does itnot involve Quaternion numbers at all anyway? /** ** This method rotates this 3D Vector around the X/Y/Z axis byamounts ** angleX/angleY/angleZ around the points centerX/centerY/centerY */ public void rotate3D(double angleX, double angleY, double angleZ, double centerX, double centerY, double centerZ){ double sinX, cosX; double sinY, cosY; double sinZ, cosZ; double tempX, tempY, tempZ; sinX = Math.sin(angleX); cosX = Math.cos(angleX); sinY = Math.sin(angleY); cosY = Math.cos(angleY); sinZ = Math.sin(angleZ); cosZ = Math.cos(angleZ); tempX = x - centerX; tempY = y - centerY; tempZ = z - centerZ; double xy = tempY*cosX - tempZ*sinX; double xz = tempY*sinX + tempZ*cosX; double xx = tempX; tempX = xx; tempY = xy; tempZ = xz; double yx = tempX*cosY + tempZ*sinY; double yz = -tempX*sinY + tempZ*cosY; tempX = yx; tempZ = yz; double zx = tempX*cosZ - tempY*sinZ; double zy = tempX*sinZ + tempY*cosZ; tempX = zx; tempY = zy; tempX += centerX; tempY += centerY; tempZ += centerZ; x = tempX; y = tempY; z = tempZ; }> Ive add c.g.a to the newsgroups as its probably a more appropriate forum> for this.> I have written a program to display Quaternion Julia set fractals. If> you dont know what these are then I think it is sufciant to know> that they are 4D object (in Quaternion space - I guess that is a> unique type of 4D space, with its own set of rules?). I can display> this object in 3D (using raytracing), ignoring the 4th dimension (I> can of course set the 4th to any number but it remains static for> each 3D image). I have programmed this in such a way that I can> rotate this in 3 Dimensions, ie rotate the view cube to form a> different view - so I would like to be able to rotate the (this is> gonna sound silly) 4D cube to form another view.I would not think of them as quaternions as I dont think its helpful in> this case: you have a 4D object you would like to display in 3D by chosing> a 3D slice through it. You already have rotations in 3D. What you need> is rotations involving the 4th dimension, i.e. the 4th axis.Consider a similar situation in 3D, applied to a sphere, the earth say. If> you ignore/x the north-south axis you would have the rotation in the> plane of the equator, the normal rotation of the earth. Then combine these> with rotations taking the poles towards points on the equator, i.e. in> planes passing through the poles, to get the full set of 3D rotations.Your situation is similar but in 4D. You already have three dimensional> rotations. To generate the full set of 4D rotations you need to combine> these with rotations from the 4th axis to all possible axes in 3D, e.g. in> planes through this fourth axis.It should be possible to devise an interface for this, such a sphere,> which you click on to indicate the 3D axis which will be paired with the> 4th axis to generate the rotation into the fourth dimension. Rotations in> 4D have six degrees of freedom, the three DOF youve already implemented +> the three DOF of the rotations into 4D.John More like 2300 years. Euclid proved there is an innitude of primes.Naah, actually, he never mentions innite at all.He just does: Given any [nite] set of primes, to construct a primenot in the set. More like 2300 years. Euclid proved there is an innitude of primes.Naah, actually, he never mentions innite at all.He just does: Given any [nite] set of primes, to construct a prime> not in the set.Does the usual proof actually construct a prime? More like 2300 years. Euclid proved there is an innitude of primes.> Naah, actually, he never mentions innite at all.> He just does: Given any [nite] set of primes, to construct a prime> not in the set.Does the usual proof actually construct a prime?No, but it shows that such a prime must exist. More like 2300 years. Euclid proved there is an innitude of primes.> Naah, actually, he never mentions innite at all.> He just does: Given any [nite] set of primes, to construct a prime not in the set.> Does the usual proof actually construct a prime?No, but it shows that such a prime must exist.Since nobody else sketched the argument, I will.Let p1, p2, p3, ..., pn be the rst n primes. Considerthe number (p1*p2*...*pn)+1. This number has a remainderof 1 when divided by any prime up to pn. Therefore eitherthe number is prime, or if it is composite then its primefactors are all larger than pn.Thus given the rst n primes where n is nite,there exists another prime which is larger than allof them.If p1, p2, ... pn are any n primes (not the rst n),then youve proved as Virgil says that there exists anotherprime not in this list, but its not necessarilya larger one. For instance, (3*5*13)+1 has 2 and 7 asprime factors. Still, since that means no nite list ofprimes is complete it is sufcient to prove there areinnitely many primes. - Randy More like 2300 years. Euclid proved there is an innitude of primes.Naah, actually, he never mentions innite at all.He just does: Given any [nite] set of primes, to construct a prime> not in the set.Thus he proved that the number of primes is not nite, though perhaps he did not express his result in quite those terms. More like 2300 years. Euclid proved there is an innitude of primes.Naah, actually, he never mentions innite at all.He just does: Given any [nite] set of primes, to construct a prime> not in the set.Does he prove unique factorisation of the integers?Isnt that also necessary?Phil-- Unpatched IE vulnerability: Web Archive buffer overowDescription: Possible automated code execution.Reference: http://msgs.securepoint.com/cgi-bin/get/bugtraq0303/107.html= >> More like 2300 years. Euclid proved there is an innitude of primes. Naah, actually, he never mentions innite at all. He just does: Given any [nite] set of primes, to construct a prime>> not in the set.> Does he prove unique factorisation of the integers?> Isnt that also necessary?No, because the key step is tofind a number that is not divisible by anyof the primes in the given (nite) set. Either this number is prime, orit has (at least one) prime divisor not in the set. Unique factorizationis not needed.-- Dave SeamanJudge Yohns mistakes revealed in Mumia Abu-Jamal ruling. We can understand the proof that the set of primes has no largest member. >Thus, we may conclude that some innite primes exist.We may? No, We PrettyDoug We can understand the proof that the set of>>primes has no largest member. Thus, we may conclude that some innite>>primes exist.>> Nonsense. If you conclude that, I conclude that you dont know much>> mathematics. Assuming youre talking about the usual denition of>> primes, primes are integers. There are no innite integers.>>Doesnt the compactness theorem for FOL imply that there are>non-archimedean models of the integers?>> Its not entirely clear to me what a non-archimedean model> of the integers would be. Yes, the compactness theorem> shows that there are non-standard, very large, models of> the _theory of_ the integers. These models include things> which might reasonably be called innite.>> That does not imply that there exists an innite integer, however.>>There are. They are, of course, nonstandard.>>A nonstandard prime is not a _prime_.>>Maybe we should start with the question of how many legs a>dog has if you call the tail a leg...>All the constructions that Im aware of and understand (that leaves out>>ultralters) create nonstandard integers. Construction is in quotes>>because they arent really constructions -- theyre proofs of existence.>>However, if you start with the standard rst order axioms of integers, and>>nd a model with innite elements, how can you not call the elements of>>that model integers? They t all the axioms of integers, but were going>>to call them monsters? No, theyre integers. >>Huh? _Any_ object whatever is an element of some model of the>theory of the integers. By your criterion _everything_ is an integer.Well, it might be true that people who spend half their lives working withnonstandard models of the integers get into the habit of calling thesethings just integers. No problem with that - just like algebraic numebrtheorists often refer to algebraic integers just as integers.There is no largest prime - therefore there is an innite prime, then themost appropriate and helpful answer is surely `Nonsense or maybe even*Nonsense* (could even be a case for NONSENSE!) To start discussinginnite primes in nonstandard models of the integers in the companyof such a poster does not seem very helpful.Derek Holt.>>Since theyre not in the>>standard model, theyre obviously nonstandard, but theyre still integers.>>As you say, it does not imply that there exists an innite integer. I>>suspect that there are nonstandard models without innite integers -- some>>numbers are innite, but all integers are nite.>>Jon Miller>>************************>>David C. Ullrich N^* - N>> Excuse me (again) for being stupid, but is that expression>> meaningful?>> [I ask because I know exactly nothing about a subject called>> non-standard analysis.]Its intended to mean the set difference, which I would write N* N.The tricky part is that although N* is an internal set in NSA, N is not.> Both N and (N* N) are external sets, which means that in some sense> they are not quite meaningful sets in NSA.But then, its common to keep leaping between internal reasoning and> external reasoning in NSA.This is the whole point of using NSA :-)-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.htmlNeedless to say, I had the last laugh. Alan Partridge, _Bouncing Back_ (14 times) However, if you start with the standard rst order axioms of integers,> andfind a model with innite elements, how can you not call the elements> of> that model integers?No.> They t all the axioms of integers,No. Not the second order induction axiom (a subset of N containing 1and the successor of each of its elements is N).> but were going> to call them monstersNo, only the largest sporadic simple group is called a monster.We call them nonstandard integers.-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.htmlNeedless to say, I had the last laugh. Alan Partridge, _Bouncing Back_ (14 times) =Proof the following proposition or give a counterexample:For all homoeomorphisms (not sure about the spelling, I mean an openand closed bijective mapping) between two open subsets of (of perhapstwo different) euclidean vector spaces, the dimensions of the twoeuclidean spaces are identical.Is this perhaps a famous theorem (at least in nite dimensions, whatabout dimensions of innite cardinality?) whose name I dont know? Proof the following proposition or give a counterexample:>>For all homoeomorphisms (not sure about the spelling, I mean an open>and closed bijective mapping) between two open subsets of (of perhaps>two different) euclidean vector spaces, the dimensions of the two>euclidean spaces are identical.>The nite case has been answered already>Is this perhaps a famous theorem (at least in nite dimensions, what>about dimensions of innite cardinality?) whose name I dont know?>As to the innite case: one might consider two innite versions of R^n:1. R^kappa, for innite cardinals kappa, with the product topology2. ell_2(kappa), the set of square-summable sequences of length kappa, In either case the answer is much easier than that for R^n: kappa is the topological weight of any nonemptyopen set; so. yes, the dimensions have to equal in that case as well.KP-- E-MAIL: K.P.Hart@EWI.TUDelft.NL PAPER: Faculty EWIPHONE: +31-15-2784572 TU DelftFAX: +31-15-2786178 Postbus 5031URL: http://aw.twi.tudelft.nl/~hart 2600 GA Delft the Netherlands Proof the following proposition or give a counterexample:For all homoeomorphisms (not sure about the spelling, I mean an open> and closed bijective mapping) between two open subsets of (of perhaps> two different) euclidean vector spaces, the dimensions of the two> euclidean spaces are identical.Is this perhaps a famous theorem (at least in nite dimensions, what> about dimensions of innite cardinality?) whose name I dont know? As G.A. Edgar noted, its a version of Brouwers Invariance of Domain Theorem: Theorem: If X can be imbedded in R^n as an open subset, then h(X) is an open subset of R^n for _any_ imbedding h: X --> R^n. Your result is a corollary. If U subseteq R^m and V subseteq R^n are open sets and h: U --> V is a homeomorphism between them, it follows that m = n. (Otherwise, say m < n. Then R^m sits inside R^n as a coordinate hyperplane which has empty interior. This shows that U can be imbedded in R^n as something other than an open subset. But h imbeds it as V, which _is_ open -- contradiction.) A proof of Brouwers theorem requires some machinery -- just what machinery dependson what kinds of things you already know ... = Theorem: If X can be imbedded in R^n as an open subset, then> h(X) is an open subset of R^n for _any_ imbedding> h: X --> R^n. Your result is a corollary. If U subseteq R^m and V subseteq R^n> are open sets and h: U --> V is a homeomorphism between them, it> follows that m = n. (Otherwise, say m < n. Then R^m sits inside> R^n as a coordinate hyperplane which has empty interior. This shows> that U can be imbedded in R^n as something other than an open subset.> But h imbeds it as V, out already. A proof of Brouwers theorem requires some machinery -- just what> machinery dependson what kinds of things you already know ...Concerning algebraic topology, I know what homotopy is, but am not(yet) familiar with homology. I doubt that homotopy is of any usebecause e.g. open balls are contractible and thus have trivialhomotopy.Are there any measure-theoretic invariants that can be used tocharacterize full-dimensionality of sets? That is, is the propertymeasure zero preserved under homeomorphisms?My original intention was to prove that the dimension of a manifold iswell-dened (i.e. given two atlases, they map two the same R^n). Arethere any other ways to do this? >> Theorem: If X can be imbedded in R^n as an open subset, then>> h(X) is an open subset of R^n for _any_ imbedding>> h: X --> R^n. Your result is a corollary. If U subseteq R^m and V subseteq R^n>> are open sets and h: U --> V is a homeomorphism between them, it>> follows that m = n. (Otherwise, say m < n. Then R^m sits inside>> R^n as a coordinate hyperplane which has empty interior. This shows>> that U can be imbedded in R^n as something other than an open subset.>> But h imbeds it as V, which _is_ open -- >> A proof of Brouwers theorem requires some machinery -- just what>> machinery dependson what kinds of things you already know ...>Concerning algebraic topology, I know what homotopy is, but am not>(yet) familiar with homology. I doubt that homotopy is of any use>because e.g. open balls are contractible and thus have trivial>homotopy.>Are there any measure-theoretic invariants that can be used to>characterize full-dimensionality of sets? That is, is the property>measure zero preserved under homeomorphisms?>My original intention was to prove that the dimension of a manifold is>well-dened (i.e. given two atlases, they map two the same R^n). Are>there any other ways to do this?You could also use the Lebesgue dimension (a.k.a. covering dimensionor topological dimension). This is invariant under homeomorphisms anddim(R^n) = n. This isnt a measure-theoretic dimension, though.You can take a look at Hurewicz & Wallmans Dimension Theory formore information.John A proof of Brouwers theorem requires some machinery -- just what> machinery dependson what kinds of things you already know ...>Concerning algebraic topology, I know what homotopy is, but am not>(yet) familiar with homology. I doubt that homotopy is of any use>because e.g. open balls are contractible and thus have trivial>homotopy.The usual proofs condisider the open ball with the center point removed(or the one point compactications). This set is homotopic to asphere, which is not contractible. This allows a proof that open setsin R^2 and open sets in higher dimensions are not homeomorphic usingfundamental (rst homotopy) groups.If you know about higher homotopy groups, this will also give the generalresult. However, the higher homotopy groups are not so easy to calculate.Typically, the invariance theorem is proved using homology theory.>Are there any measure-theoretic invariants that can be used to>characterize full-dimensionality of sets? That is, is the property>measure zero preserved under homeomorphisms?No, it is not. There is a homeomorphism from the real line to itselfwhich takes a set of measure zero to one of positive measure. Essentially,the Cantor ternary set is stretched to a set of positive measure.>My original intention was to prove that the dimension of a manifold is>well-dened (i.e. given two atlases, they map two the same R^n). Are>there any other ways to do this?As another poster suggested, you can use the Lebesgue covering dimension.The problem is that proving the dim(R^n)=n is again not easy. I belive itrequires the fact that a sphere is not a retract of the closed ball, which is also proved using homology (usually).---Dan Grubb ...>>My original intention was to prove that the dimension of a manifold is>>well-dened (i.e. given two atlases, they map two the same R^n). Are>>there any other ways to do this?>>As another poster suggested, you can use the Lebesgue covering dimension.>The problem is that proving the dim(R^n)=n is again not easy. I belive it>requires the fact that a sphere is not a retract of the closed ball, which >is also proved using homology (usually).Thats true, but there are also direct geometric proofs that thesphere is not a retract of the closed ball. There was a recentsci.math thread on that topic (Non-contractibility of S^n, orsomething like that).John Mitchell Are there any measure-theoretic invariants that can be used to> characterize full-dimensionality of sets? That is, is the property> measure zero preserved under homeomorphisms?Not if measure means Lebesgue measure.-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.htmlNeedless to say, I had the last laugh. Alan Partridge, _Bouncing Back_ (14 times) Proof the following proposition or give a counterexample:For all homoeomorphisms (not sure about the spelling, I mean an open> and closed bijective mapping) between two open subsets of (of perhaps> two different) euclidean vector spaces, the dimensions of the two> euclidean spaces are identical.Is this perhaps a famous theorem (at least in nite dimensions, what> about dimensions of innite cardinality?) whose name I dont know?Invariance of the domain ... proved by Brouwer, I believe.When it says euclidean vector spaces, it means nite-dimensional.-- G. A. Edgar http://www.math.ohio-state.edu/~edgar/ Proof the following proposition or give a counterexample:For all homoeomorphisms (not sure about the spelling,Usually homeomorphism.> I mean an open> and closed bijective mapping) between two open subsets of (of perhaps> two different) euclidean vector spaces, the dimensions of the two> euclidean spaces are identical.In the local homology groups of an open subset of R^n vanish exceptin dimension n. (See texts on algebraic topology).> Is this perhaps a famous theoremRaasonably; it hasnt anyones name AFAIK.> (at least in nite dimensions, what> about dimensions of innite cardinality?)Dunno about that.-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.htmlNeedless to say, I had the last laugh. Alan Partridge, _Bouncing Back_ (14 times)X-Cise: tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Punge: Micro$oft = at 02:23 PM, Robin Chapman homology groups of an open subset of R^n vanish except>in dimension n. (See texts on algebraic topology).Whats H_1 of an annulus?-- Shmuel (Seymour J.) Metz, SysProg and JOATnot at 02:23 PM, Robin the local homology groups of an open subset of R^n vanish except>>in dimension n. (See texts on algebraic topology).Whats H_1 of an annulus?Its isomorphic to Z. Now is that a homework question?-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.htmlNeedless to say, I had the last laugh. Alan Partridge, _Bouncing Back_ (14 times) =Ive been reading his posts and I have a hard time following them lately.Here are some suggestions/questions I have for him.1. What is a key variable? Last I heard, there was no such thing as a keyvariable, however, I think you might mean independent variables. You shouldknow about this term.2. Use the right terminology. Your biggest problem is that you usenonstandard terms and expect everyone to know what youre talking about.Just because we dont know what youre talking about doesnt mean werestupid, as you insinuate.3. Cut the personal attacks; they are irrelevent to the math and make youappear childish.David Moran Ive been reading his posts and I have a hard time following them lately.> Here are some suggestions/questions I have for him.1. What is a key variable? Last I heard, there was no such thing as a key> variable, however, I think you might mean independent variables. You should> know about this term.2. Use the right terminology. Your biggest problem is that you use> nonstandard terms and expect everyone to know what youre talking about.> Just because we dont know what youre talking about doesnt mean were> stupid, as you insinuate.3. Cut the personal attacks; they are irrelevent to the math and make you> appear childish.If they thought there was a chance that their suggestions would be taken seriously, I imagine others could add quite a few more.Gib Ive been reading his posts and I have a hard time following them lately.> Here are some suggestions/questions I have for him.> 1. What is a key variable? Last I heard, there was no such thing as a key> variable, however, I think you might mean independent variables. You should> know about this term.> 2. Use the right terminology. Your biggest problem is that you use> nonstandard terms and expect everyone to know what youre talking about.> Just because we dont know what youre talking about doesnt mean were> stupid, as you insinuate.> 3. Cut the personal attacks; they are irrelevent to the math and make you> appear childish.If they thought there was a chance that their suggestions would be taken > seriously, I imagine others could add quite a few more.Like:4. Dont post when drunk or when in full-blown delusionalmode.5. Talk to somebody in your local community health services. - Randy Ive been reading his posts and I have a hard time following them lately.> Here are some suggestions/questions I have for him.> 1. What is a key variable? Last I heard, there was no such thing as a key> variable, however, I think you might mean independent variables. You should> know about this term.> 2. Use the right terminology. Your biggest problem is that you use> nonstandard terms and expect everyone to know what youre talking about.> Just because we dont know what youre talking about doesnt mean were> stupid, as you insinuate.> 3. Cut the personal attacks; they are irrelevent to the math and make you> appear childish.If they thought there was a chance that their suggestions would be taken > seriously, I imagine others could add quite a few more.Gib4. Cut down on the conspiracy speculations (actually, get rid of them completely).---J K Hauglandhttp://www.neutreeko.com Ive been reading his posts and I have a hard time following them lately.> Here are some suggestions/questions I have for him.>> 1. What is a key variable? Last I heard, there was no such thing as akey> variable, however, I think you might mean independent variables. Youshould> know about this term.>> 2. Use the right terminology. Your biggest problem is that you use> nonstandard terms and expect everyone to know what youre talking about.> Just because we dont know what youre talking about doesnt mean were> stupid, as you insinuate.>> 3. Cut the personal attacks; they are irrelevent to the math and make you> appear childish.>> David Moran>>One other thing is dont use the word should. That word has nomathematical relevance. If you need the word, then you need to analyze thesituation. =its just a matter of tense, since shall is the same as must,being forms of to be. in other words,should is cognate with yet to be shown, to be --or not to be! > 2. Use the right terminology. Your biggest problem is that you use > One other thing is dont use the word should. That word has no> mathematical relevance. If you need the word, then you need to analyze the> situation.--Dec.2000 WAND Chairman Paul ONeill, reelected to Board. Newsish?http://www.rand.org/publications/randreview/issues/rr .12.00/http://members.tripod.com/~american_almanac =How do I do the following problem:Let f(x) = x^2 - 6x + 7. By completing the square, or otherwise, determinethe unique number a such that f(x) is a one-to-one function over the domain(-?,a] and over the domain [a,?).For this value of a, nd the inverses of the functions f1 and f2 denedby:f1(x) = x^2 - 6x + 7, x?af2(x) = x^2 - 6x +7, x?aTIA. How do I do the following problem:Let f(x) = x^2 - 6x + 7. By completing the square, or otherwise, determine> the unique number a such that f(x) is a one-to-one function over the domain> (-?,a] and over the domain [a,?).For this value of a, nd the inverses of the functions f1 and f2 dened> by:f1(x) = x^2 - 6x + 7, x?af2(x) = x^2 - 6x +7, x?a> TIA.f(x) = (x-3)^2 - 2Let g be the inverse of fy = (g(y) - 3)^2 - 2 y+2 = (g(y) - 3)^2+/- sqrt(y+2) = g(y) - 33 +/- sqrt(y+2) = g(y)So g(y) = 3 + sqrt(y) and g(y) = 3-sqrt(y) are both inverses of fg(y) = 3+sqrt(y) >= 3 and g(y) = 3-sqrt(y) <= 3So g(y) = 3+sqrt(y) is the inverse of f(x) for x >= 3and g(y) = 3 - sqrt(y) is the inverse of f(x) for x <= 3~ Chris How do I do the following problem:Let f(x) = x^2 - 6x + 7. By completing the square, or otherwise, determine> the unique number a such that f(x) is a one-to-one function over the domain> (-?,a] and over the domain [a,?).For this value of a,find the inverses of the functions f1 and f2 dened> by:f1(x) = x^2 - 6x + 7, x?af2(x) = x^2 - 6x +7, x?a> TIA.What have you done so far? Did you complete the square in x^2-6x+7 ? What did you get? > What have you done so far? Did you complete the square in x^2-6x+7 ?> What did you get?In completing the square I got (x-3)^2 - 2.My problem with the question is that Im unsure exactly what it is askingand how a relates to the inverses of the two functions. > What have you done so far? Did you complete the square in x^2-6x+7 ?> What did you get?In completing the square I got (x-3)^2 - 2.My problem with the question is that Im unsure exactly what it is asking> and how a relates to the inverses of the two functions.Look at the graph of any function. The inverse function,if it exists, is created by swapping the x and y axes,by reecting the graph through an imaginary 45-degreeline at y=x.A function cant be multi-valued: if you draw a verticalline, it should only intersect the graph at most once.So for a function to be invertible, any HORIZONTAL lineshould only intersect the graph at most once.That means you need to restrict your function to domainover which this property holds. If you look at the wholegraph of a quadratic, it has a symmetry. Every horizontalline that intersects it, intersects it twice. Flip itaround and youd have a curve with two y-values for everyx which is not a valid function.Thats the purpose of the a: to restrict the domain to aplace where you can ip the curve sideways and not havea multi-valued curve. - Randy > What have you done so far? Did you complete the square in x^2-6x+7 ?> What did you get?> In completing the square I got (x-3)^2 - 2.> My problem with the question is that Im unsure exactly what it is asking> and how a relates to the inverses of the two functions.Look at the graph of any function. The inverse function,> if it exists, is created by swapping the x and y axes,> by reecting the graph through an imaginary 45-degree> line at y=x.A function cant be multi-valued: if you draw a vertical> line, it should only intersect the graph at most once.> So for a function to be invertible, any HORIZONTAL line> should only intersect the graph at most once.That means you need to restrict your function to domain> over which this property holds. If you look at the whole> graph of a quadratic, it has a symmetry. Every horizontal> line that intersects it, intersects it twice. With one important exception, the horizontal through the vertex.> Flip it> around and youd have a curve with two y-values for every> x which is not a valid function.Thats the purpose of the a: to restrict the domain to a> place where you can ip the curve sideways and not have> a multi-valued curve. - Randy complete the square in x^2-6x+7 ?> What did you get?In completing the square I got (x-3)^2 - 2.My problem with the question is that Im unsure exactly what it is asking> and how a relates to the inverses of the two functions.>For some functions, like f(x) = m*x+b with m <> 0, there is only one x for any y, so a uniquely dened inverse, hereg(x) = (x-b)/m, can be found. For many y = f(x) functions there is sometimes more than one x for some values of x, so that there is no unique inverse. In these cases it is sometimes possible to split up the domain (set of inputs) for the function into pieces, possibly intervals, on which there is only only one x for each y, and thenfind a separate inverse on each piece. For example f(x) = x^2 has no total inverse, but the peice of f(x) = x^2 for which x >=0, has inverse g(x) = sqrt(x), and the piece for which x <= 0 has inverse h(x) = - sqrt(x). Consider that equation y = (x-3)^ - 2 is a parabola with vertex at (3,-2) and vertical line of symmetry {(x,y) | x = 3 }.It might help to sketch this graph, manually or on a graphic calculator. Have you done this? > What have you done so far? Did you complete the square in x^2-6x+7 ?>> What did you get?>> In completing the square I got (x-3)^2 - 2.>> My problem with the question is that Im unsure exactly what it is> asking and how a relates to the inverses of the two functions.-- Ignacio Larrosa Ca.96estroA Coru.96a (Espa.96a)ilarrosaQUITARMAYUSCULAS@mundo-r.com =Certain symbols didnt come out right.> How do I do the following problem:>> Let f(x) = x^2 - 6x + 7. By completing the square, or otherwise, determine> the unique number a such that f(x) is a one-to-one function over thedomain> (-?,a] and over the domain [a,?).? is innity> For this value of a,find the inverses of the functions f1 and f2 dened> by:>> f1(x) = x^2 - 6x + 7, x?a? is less than or equal to> f2(x) = x^2 - 6x +7, x?a? is greater than or equal to> TIA.>> When one has intuited an innite proof, which cant be> communicated to someone lacking this sort of intuition, one can> nevertheless use language to sort of nudge other people with> necessary intuitions into intuiting the proof construction.Reminds me of something--The rst evening Zen master Momataki arrived at Rain Mountain Monastery the monks requested their new master show them the way. When Momataki assented with a nod and pointed to the rising moon all but two of the assembled looked at his nger.I like the anecdote, but to my lay self it doesnt sound much like a way of doing maths ;) [.snip.]>>My point in using the example is to show that certain posters are full>>of it, as they *have* been attacking rather basic algebra, especially>>with one particularly annoying tactic.>>Its not such a complicated thing in analysis when you have terms>>independent of a particular variable to set that variable to 0 to>>clear it out, but these posters attacked that basic technique and>>claimed that m=0 was a special case!!!> Your basic technique seems to be a mess. Whenever people ask you>> what the term is, instead of answering you just start new>> threads. You claim something changes, when people ask you what and>> how, you dont answer, you just start new threads and repeat the same>> claim.>>Thats a rather interesting falsehood.Really? Lets see:>A key expression has long been g_1 = a_1 x + uf, where, though not>seen, certain variables are dependent on m, such that some posters>want me to write g_1(m) = a_1(m) x + uf, and at m=0, g_1 = uf, as uf>is the independent term.>>So it is not true that I dont answer what the independent term is.[changes], you just start new threads and repeat the same claim.What changed?I repeatedly explain. I have P(m) with a factor that is f^2 andanother that is g_1, where g_1 varies with P(m), but has uf as anindependent term i.e. a term that doesnt change as m changes.Given that P(m) also has an independent term that is u^2 f^2(3x + uf),I now move to P(m)/f^2, where I know that the independent terms haveto have changed, as in one case you have uf, but with P(m)/f^2, theindependent term is now u^2(3x + uf), so theres been a clear andvisible change. The f had to divide off, so now the independent termfor that factor is u. That is, it was uf, now it has to be u, whenyou divide P(m) by f^2.Given the condition that f is coprime to 3, x, and I toss in u, justin case, its clear that u^2(3x + uf) is coprime to f.So now, from the terms *independent of m* I know that dividing P(m) byf^2 means that f is divided off of uf, which as an independent term,is not affected by the value of m, so then in general g_1 has f as afactor.>> I went to the Hong Kong forum you were recommending. I noted that as>> soon as a rather basic question about your basic technique was>> asked, you ran away like a frightened little kid. No wonder you>> havent been posting there any more.>>I last posted there a few days ago, which doesnt mean I wont post>there again.>>The poster doesnt give a link so Ill give one for readers who wish>to see the full discussion on the Hong Kong website, where theres an>additional advantage as they allow use of LaTeX.>>See http://mathdb.math.cuhk.edu.hk/forum/e_show.php?msg=782>> Let me quote it here, maybe youll have the courage to actually answer> As there are continued postings it might help to consider the>> alternative.> So, consider again $P(m)=g_1 g_2 g_3$, $g_1 = a_1 x + uf$ where its>> established that $uf$ is independent of $m$ as determined by setting>> $m=0$, note $P(0)=u^2f^2(3x + uf)$.> Now suppose that instead of $f$ as a factor $g_1$ had $sqrt{f}$ when>> $m=5$, then youd have> $g_1/sqrt{f} = a_1/sqrt{f} x + usqrt{f}$> so the independent term has changed.> You were asked which function had an independent term that changed,>> what it changed from, and what it changed to.>>Oh, I remember that, as some poster kept going on and on asking the>same question after I answered.Really? Where was the answer where you said WHAT changed, and from> what to what? You replied, but you never ->answered<-. As usual.In reality, I repeatedly explain, and the posters like this one just*claim* I dont, and people seem to believe him, which I think he seesas approval of his lying. Again, I have P(m) with a factor that isf^2 and another that is g_1, where g_1 varies with P(m), but has uf asan independent term i.e. a term that doesnt change as m changes.Given that P(m) also has an independent term that is u^2 f^2(3x + uf),I now move to P(m)/f^2, where I know that the independent terms haveto have changed, as in one case you have uf, but with P(m)/f^2, theindependent term is now u^2(3x + uf), so theres been a clear andvisible change.Given the condition that f is coprime to 3, x, and I toss in u, justin case, its clear that u^2(3x + uf) is coprime to f.So now, from the terms *independent of m* I know that dividing P(m) byf^2 means that f is divided off of uf, which as an independent term,is not affected by the value of m, so then in general g_1 has f as afactor.James Harris = [.snip.]> I have P(m) with a factor that is f^2 and>another that is g_1, where g_1 varies with P(m), but has uf as an>independent term i.e. a term that doesnt change as m changes.>>Given that P(m) also has an independent term that is u^2 f^2(3x + uf),>I now move to P(m)/f^2, where I know that the independent terms have>to have changed, as in one case you have uf, but with P(m)/f^2, the>independent term is now u^2(3x + uf), so theres been a clear and>visible change. The f had to divide off, so now the independent term>for that factor is u. That is, it was uf, now it has to be u, when>you divide P(m) by f^2.>>Given the condition that f is coprime to 3, x, and I toss in u, just>in case, its clear that u^2(3x + uf) is coprime to f.>>So now, from the terms *independent of m* I know that dividing P(m) by>f^2 means that f is divided off of uf, which as an independent term,>is not affected by the value of m, so then in general g_1 has f as a>factor.I have P(m) = m^2 + 3m + 2, with a factor that is 2, and another whichis g_1 = (m+2), where g_1 varies with P(m), but has 2 as anindependent term i.e. a term that doesnt change as m changes.Given that P(m) also has an independent term that is 2, I now move toP(m)/2, where I know that the independent terms have to have changed,as in one case you have 2, but with P(m)/2 the independent term is now1, so theres been a clear and visible change. The 2 had to divideoff, so now the independent term for that factor is 1. That is, it was2, now it has to be 1, when you divide P(m) by 2.Given the condition that 2 is coprime to 1, it is clear that 1 iscoprime to 2.So now, from the terms *independent of m* I know that dividing P(m) by2 means that 2 is divided off 2, which as an independent term is notaffected by the value of m, so then in general g_1 has 2 as a factor.[Here, P(m) = (m+2)(m+1), g_1(m) = m+2, g_2(m) = m+1].So, turns out that for every integer value of m, m+2 is a multiple of2.Excellent...The error lies in the nal paragraph, as it always has. I know thatdividing P(m) by f^2 means that f is divided of uf is an unjustied(and in fact false) assertion. The claim So then in general g_1 has fas a factor is unjustied, and in general false. a reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can criticize. A great many people are staggered to this extent, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de Morgan [.snip.]> I have P(m) with a factor that is f^2 and>another that is g_1, where g_1 varies with P(m), but has uf as an>independent term i.e. a term that doesnt change as m changes.>>Given that P(m) also has an independent term that is u^2 f^2(3x + uf),>I now move to P(m)/f^2, where I know that the independent terms have>to have changed, as in one case you have uf, but with P(m)/f^2, the>independent term is now u^2(3x + uf), so theres been a clear and>visible change. The f had to divide off, so now the independent term>for that factor is u. That is, it was uf, now it has to be u, when>you divide P(m) by f^2.>>Given the condition that f is coprime to 3, x, and I toss in u, just>in case, its clear that u^2(3x + uf) is coprime to f.>>So now, from the terms *independent of m* I know that dividing P(m) by>f^2 means that f is divided off of uf, which as an independent term,>is not affected by the value of m, so then in general g_1 has f as a>factor.I have P(m) = m^2 + 3m + 2, with a factor that is 2, and another which> is g_1 = (m+2), where g_1 varies with P(m), but has 2 as an> independent term i.e. a term that doesnt change as m changes.Heres a fascinating case of Arturo Magidin clearly lying by trying touse something true only in the ring of *integers*.In the actual proof that I use you can see f^2 as a factor asP(m) = f^2((m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f)yet here you see the poster using an example where 2 is NOT a visiblefactor.Look further and see dramatic desperation. > Given that P(m) also has an independent term that is 2, I now move to> P(m)/2, where I know that the independent terms have to have changed,> as in one case you have 2, but with P(m)/2 the independent term is now> 1, so theres been a clear and visible change. The 2 had to divide> off, so now the independent term for that factor is 1. That is, it was> 2, now it has to be 1, when you divide P(m) by 2.Given the condition that 2 is coprime to 1, it is clear that 1 is> coprime to 2.So now, from the terms *independent of m* I know that dividing P(m) by> 2 means that 2 is divided off 2, which as an independent term is not> affected by the value of m, so then in general g_1 has 2 as a factor.> [Here, P(m) = (m+2)(m+1), g_1(m) = m+2, g_2(m) = m+1].So, turns out that for every integer value of m, m+2 is a multiple of> 2.> Excellent...> And yes, Arturo Magidin is a graduate of Berkeley Universitys Ph.Dprogram in mathematics, which tells me a lot about what math people*actually* learn there.Clearly Berekeley is NOT the place to get a math degree, as shown byArturo Magidin.> The error lies in the nal paragraph, as it always has. I know that> dividing P(m) by f^2 means that f is divided of uf is an unjustied> (and in fact false) assertion. The claim So then in general g_1 has f> as a factor is unjustied, and in general false.The error is in Arturo Magidin using a result only valid in the ringof integers, as what he claims isnt even true in the ring ofalgebraic integers.Hes rather pathetic, now isnt he?> Arturo Magidin> magidin@math.berkeley.eduAnd whats particularly pathetic is his emphasizing his Berkeleyeducation to the shame of that institution, the place that gave thisanti-mathematician his degree.I think their entire math department should be shut down.James Harris And yes, Arturo Magidin is a graduate of Berkeley Universitys Ph.D> program in mathematics, which tells me a lot about what math people> *actually* learn there.And yes, James Harris is an idiot who *still* doesnt know its not calledBerkeley University in spite of having been told this before.> Clearly Berekeley is NOT the place to get a math degree, as shown by> Arturo Magidin.Clearly Vanderbilt is NOT the place to learn to get your facts straight,as shown by James Harris.-- Wayne Brown (HPCC #1104) | When your tails in a crack, you improvisefwbrown@bellsouth.net | if youre good enough. Otherwise you give | your pelt to the trapper.e^(i*pi) = -1 -- Euler | -- John Myers Myers, Silverlock >> [.snip.] I have P(m) with a factor that is f^2 and>>another that is g_1, where g_1 varies with P(m), but has uf as an>>independent term i.e. a term that doesnt change as m changes.>>Given that P(m) also has an independent term that is u^2 f^2(3x + uf),>>I now move to P(m)/f^2, where I know that the independent terms have>>to have changed, as in one case you have uf, but with P(m)/f^2, the>>independent term is now u^2(3x + uf), so theres been a clear and>>visible change. The f had to divide off, so now the independent term>>for that factor is u. That is, it was uf, now it has to be u, when>>you divide P(m) by f^2.>>Given the condition that f is coprime to 3, x, and I toss in u, just>>in case, its clear that u^2(3x + uf) is coprime to f.>>So now, from the terms *independent of m* I know that dividing P(m) by>>f^2 means that f is divided off of uf, which as an independent term,>>is not affected by the value of m, so then in general g_1 has f as a>>factor. I have P(m) = m^2 + 3m + 2, with a factor that is 2, and another which>> is g_1 = (m+2), where g_1 varies with P(m), but has 2 as an>> independent term i.e. a term that doesnt change as m changes.>>Heres a fascinating case of Arturo Magidin clearly lyingHeres a fascinating case of James Harris engaging in ad hominemsbecause his math fails him.> by trying to>use something true only in the ring of *integers*.Nowhere in your presentation do you use anything about the fact thatyou are in the ring of algebraic integers. >In the actual proof that I use you can see f^2 as a factor as>>P(m) = f^2((m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f)>>yet here you see the poster using an example where 2 is NOT a visible>factor.So what? 2 is a factor of P(m) = m^2+3m+2 for every integer. Do youdeny that?Nowhere in your argument do you requre the factor to be visible. Youonly require it to be a factor.>Look further and see dramatic desperation.No need; you demonstrate the desperation quite thoroghly.>> Given that P(m) also has an independent term that is 2, I now move to>> P(m)/2, where I know that the independent terms have to have changed,>> as in one case you have 2, but with P(m)/2 the independent term is now>> 1, so theres been a clear and visible change. The 2 had to divide>> off, so now the independent term for that factor is 1. That is, it was>> 2, now it has to be 1, when you divide P(m) by 2. Given the condition that 2 is coprime to 1, it is clear that 1 is>> coprime to 2. So now, from the terms *independent of m* I know that dividing P(m) by>> 2 means that 2 is divided off 2, which as an independent term is not>> affected by the value of m, so then in general g_1 has 2 as a factor.> [Here, P(m) = (m+2)(m+1), g_1(m) = m+2, g_2(m) = m+1]. So, turns out that for every integer value of m, m+2 is a multiple of>> 2. Excellent...>> And yes, Arturo Magidin is a graduate of Berkeley Universitys Ph.D>program in mathematics, which tells me a lot about what math people>*actually* learn there.I do not see anything that addresses the math. Why?>Clearly Berekeley is NOT the place to get a math degree, as shown by>Arturo Magidin.I do not see anything that addresses the math?>> The error lies in the nal paragraph, as it always has. I know that>> dividing P(m) by f^2 means that f is divided of uf is an unjustied>> (and in fact false) assertion. The claim So then in general g_1 has f>> as a factor is unjustied, and in general false.>>The error is in Arturo Magidin using a result only valid in the ring>of integers, as what he claims isnt even true in the ring of>algebraic integers.What is this mystery result?For every integer value of m, P(m) is divisible by 2 in the ring ontegers and in the ring of algebraic integers. Your argument onlyrelies on integer values of m, so there is no difference between thefalse argument above and your false argument. [more desperate ad hominems deleted] such a reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can criticize. A great many people are staggered to this extent, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de Morgan think their entire math department should be shut down.Are you like this with the people at work, too? Im curious? I think their entire math department should be shut down.Are you like this with the people at work, too? Im curious?Mathematicians have proven to be...weak opponents.Im bored.Do I have to challenge your physical lives before any of you rise to the challenge?Dont worry, why should I bother?Youre going to die anyway.James Harris Mathematicians have proven to be...weak opponents.>> Im bored.>> Do I have to challenge your physical lives before any of you rise to the challenge?>> Dont worry, why should I bother?>> Youre going to die anyway.>> James HarrisWatch out everyone! Hes getting ready to blow!!!--A fool and his proof are soon refuted.--Democracy: The triumph of popularity over principle.--http://www.crbond.com > I think their entire math department should be shut down.>> Are you like this with the people at work, too? Im curious?>> Mathematicians have proven to be...weak opponents.>> Im bored.>> Do I have to challenge your physical lives before any of you rise to thechallenge?>> Dont worry, why should I bother?>> Youre going to die anyway.> James HarrisYou are so immature that it is scary. If you would harm people overmathematics, there is something SERIOUSLY wrong with you.David Moran > I think their entire math department should be shut down.>> Are you like this with the people at work, too? Im curious?>> Mathematicians have proven to be...weak opponents.>> Im bored.>> Do I have to challenge your physical lives before any of you rise to the> challenge?>> Dont worry, why should I bother?>> Youre going to die anyway.> James HarrisYou are so immature that it is scary. If you would harm people over> mathematics, there is something SERIOUSLY wrong with you.David MoranYou dont understand as *I* wont physically harm mathematicians.Why bother? Youre going to die anyway.James Harris [.snip.]>My point in using the example is to show that certain posters are full>of it, as they *have* been attacking rather basic algebra, especially>with one particularly annoying tactic.>>Its not such a complicated thing in analysis when you have terms>independent of a particular variable to set that variable to 0 to>clear it out, but these posters attacked that basic technique and>claimed that m=0 was a special case!!!> Your basic technique seems to be a mess. Whenever people ask you> what the term is, instead of answering you just start new> threads. You claim something changes, when people ask you what and> how, you dont answer, you just start new threads and repeat the same> claim.>>Thats a rather interesting falsehood. Really? Lets see:A key expression has long been g_1 = a_1 x + uf, where, though not>>seen, certain variables are dependent on m, such that some posters>>want me to write g_1(m) = a_1(m) x + uf, and at m=0, g_1 = uf, as uf>>is the independent term.>>So it is not true that I dont answer what the independent term is. [changes], you just start new threads and repeat the same claim. What changed?>>I repeatedly explain. No, you repeatedly repeat. You do not explain the point where peopleask.> I have P(m) with a factor that is f^2 and>another that is g_1, where g_1 varies with P(m), but has uf as an>independent term i.e. a term that doesnt change as m changes.Meaning, g_1(0) = uf. Yes.>Given that P(m) also has an independent term that is u^2 f^2(3x + uf),Meaning, P(0) = u^2 f^2(3x+uf); yes.>I now move to P(m)/f^2, where I know that the independent terms have>to have changed, as in one case you have uf, but with P(m)/f^2, the>independent term is now u^2(3x + uf), so theres been a clear and>visible change.What a waste of space. You mean: P(0) = u^2 f^2(3x+uf) and P(0)/f^2 = u^2(3x+uf).Yes.> The f had to divide off, so now the independent term>for that factor is u. That is, it was uf, now it has to be u, when>you divide P(m) by f^2.>>Given the condition that f is coprime to 3, x, and I toss in u, just>in case, its clear that u^2(3x + uf) is coprime to f.>>So now, from the terms *independent of m* I know that dividing P(m) by>f^2 means that f is divided off of uf, which as an independent term,>is not affected by the value of m, so then in general g_1 has f as a>factor.And that last part is what you neither explain nor do I follow; norhave I seen anybody who claims to follow. What you need to explain isSo then in general g_1 has f as a factor.Thats the part I dont get.In addition, in the Hong Kong forum this is exactly what you said:http://mathdb.math.cuhk.edu.hk/forum/e_show.php?msg=782( message from 11/10/03-23:18:06) So, consider again $P(m)=g_1 g_2 g_3$, $g_1 = a_1 x + uf$ where its established that $uf$ is independent of $m$ as determined by setting $m=0$, note $P(0)=u^2f^2(3x + uf)$. Now suppose that instead of $f$ as a factor $g_1$ had $sqrt{f}$ when $m=5$, then youd have $g_1/sqrt{f} = a_1/sqrt{f} x + usqrt{f}$ so the independent term has changed.And I ask: what independent term changed? What did it change from, andwhat did it change to, assuming that it was the case that instead of fas a factor g_1 had sqrt(f) when m=5?You continue: Now suppose that at $m=7$ the factor is $f^{2/5}$, then again the independent term will change.So I ask again: what independent will term changed, assuming that at m=7the factor is f^{2/5}? The independent term of g_1? Of g_1/f? Well then, the independent term would clearly NOT be independent of $m$ if its value changed that way depending on whether $m=0$, $m=5$, or $m=7$. Which is a direct contradiction.So you are claiming that if g_1(5) was divisible by sqrt(f) andg_1(5)/sqrt(f) was coprime to f, then the independent term wouldchange. You claim this by looking at g_1(5)/sqrt(f). But you had never looked at g_1(m)/sqrt(f) before. So I am stillwondering just what it is you think you accomjplished by looking atg_1(5)/sqrt(f), and what it was you were comparing it to so you couldsay so the independent term has changed.You dont explain, you just repeat over and over the same thing. reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can criticize. A great many people are staggered to this extent, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de Morgan > Well readers, did anyone see whats wrong with this posters position? > He suggests > f_0(m).b^3 + f_1(m).b^2 + f_2(m).b + f_3(m), > where the f_i(m) are algebraic integer functions of m and f_0(0) = 1, > f_1(0) = -3, f_2(0) = 0 and f_3(0) = 0? > But the poster fails to point out that his position requires that for > certain values of m and another important variable I call f, that his > f_0(m) *must* have f as a factor, so its basically a step function. > Is that the right word step function? > I think not. I have no idea what you mean with that term. Can you explain > what you mean? > Your position requires that f_0(m) either be a unit or have f as its > only non-unit factor, depending on certain conditions as m varies from > 0 to positive innity.Yes. And so what? > The condition is that if > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > is irreducible over Q, by your position, f_0(m) must have f as its > only non-unit factor.That is correct in part. It must also have f as its only non-unit factorin some cases when that polynomial *is* reducible. So what? > P(m) = f^2((m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f) > P(m) = (a_1 x + uf)(a_2 x + uf)(a_3 x + uf) > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m). > R(m) = (m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f > R(m) = (b_1 x + u)(b_2 x + u)(b_3 x + uf) > Here reducibility over rationals of the cubic dening the as > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > has been given as an issue, and the posters position requires that his > f_0(m) vary such that its 1 if that cubic is reducible over > rationals, and f, if its irreducible over rationals. > See my other post. It is a fallacy. With m=1 and f=2, the polynomial > in a is reducible. The polynomial I come up with is: > 2b^3 + (25 + sqrt(105))/2.b^2 + (-7 + sqrt(105))/2.b - 14. > That looks ok as one of the roots is 1 as required, as one of the bs > is 1. > If it is the correct polynomial, then *each* of the coefcients has 2 > as a factor, but NOT in the ring of algebraic integers, as the middle > coefcients are arbitrarily excluded by the denition of algebraic > integers from having 2 as a factor.I am *talking* about the ring of algebraic integers. There are indeedrings where 2 is a divisor of those two factors. But that is somethingcompletely different. Such rings much more units. So lets say thatthere is a ring (the object ring) where (25 + sqrt(105))/4 is in. Why is(25 - sqrt(105))/4 *not* in that ring? What is the essential differencebetween the two? > Those who doubt that assessment can instead believe in the step > function, which somehow varies the leading coefcient from f to 1 > based on whether or not > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > is reducible over Q. > Note that for the example above, it reduces to a linear and a > quadratic.Yes, and f_0(m) is 2 in that case. > Now theres no *mathematical* way to have a function f_0(m) which will > vary in such an extreme manner depending on whether or not some cubic > is reducible over Q or not, that is consistent with the other > mathematical facts here.Why? I have been thinking about it. It is a fact that f_0(m) is f when*all three* of the as share a factor with f in the algebraic integers.In the case above the algebraic integer factors shared are 2,(-sqrt(7)+sqrt(15))/2 and (-sqrt(7)-sqrt(15))/2. All three non-unitsin the algebraic integers. (Note the case f=3 is special as in thatcase the constant term of the polynomial is divisible by f^3, and indeedall three of the as are divisible by f, so f_0(m) = 1, I will not restatethe restriction f != 3 again, and also not the trivial restriction f != 1.) > Depends on the roots a1 to a3, which two you divide by f, how the resulting > bs can be written as a quotient of an algebraic integer and a normal > integer (in lowest form), and perhaps a bit more. It is *not* possible to > give a general formula. But I have given the algorithm through which you > can calculate that number for each m. > Thats nonsense. Its not necessary to give the expression explicitly > as given that only f is being divided off, it follows that only f can > be the non-unit factor, if there is one.You are not entirely right here. f_0(m) can also be any multiple of f andany multiple of 1. But when the polynomial is reduced to primitive withalgebraic integer coefcients, it is indeed either 1 or f. > Remember, this poster is trying to cast doubt on the factorization > (b_1 x + u)(b_2 x + u)(b_3 x + uf) > which comes from the factorization > (a_1 x + uf)(a_2 x + uf)(a_3 x + uf) > where > (a_1 x + uf)(a_2 x + uf)(a_3 x + uf) = > f^2((m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f) > and the as are given by > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > which is a monic with integer coefcients.... > which works when m=1, f=sqrt(2), so if you wish to believe this poster > you need to believe in that odd function which varies from being a > unit to having f as a factor dependent on the reducibility of > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).You state the wrong condition again. f_0(m) = f when the as all threeshare a non-unit factor with f, it is 1 otherwise. All three as *can*share a non-unit factor with f even when the polynomial is reducible.But lets try it otherwise, to see why this is so. Note that the productof the factors shared is always f^2. > This poster either is unwilling to concede to the math, or is > incapable of realizing the aw in his position.Clearly this poster is unwilling to concede to the math and incapable ofrealising the aw in his position. > The reality is that a function with the behavior he needs doesnt > exist in this context, as his f_0(m) cant vary in the way he needs as > m goes from 0 to positive innity, where it is a unit for certain > values, but switches to having f as its only non-unit factor for > others.*Why* does such a function not exist in this context? That is a prettystrange argument. Such a function exists independent of context. > What Im showing here is a outlandish consequence of the posters > position, since this poster and others have continued to argue against > the mathematical argument which shows that the leading coefcient is > always monic as in fact two of the as have a factor that is f, as > shown by their terms independent of m, for all m.The leading coefcient is *not* always 1 when you want algebraic integercoefcients. And you need algebraic integer coefcients to be ableto tell whether the bs are algebraic integers or not. You can make theleading coefcient always 1 (trivially so), but in that case you do notalways have all coefcients algebraic integers. > You see, m=0 is NOT a special case.Very, very special. Because it has the property that in that caseexactly two of the as are divisible by f for every f, f vanishesalso from the polynomial in a, so the two as that are 0 are triviallydivisible by f. When m != 0 it can be shown that when there areexactly two of the as divisible by f, that the polynomial in a isreducible. (The other way around is false.) This has been provenmany times, by various posters, both in general and by specicexamples. Also, when m != 0, f does not vanish from the polynomialin a.-- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/ ...> Well readers, did anyone see whats wrong with this posters position?> He suggests > f_0(m).b^3 + f_1(m).b^2 + f_2(m).b + f_3(m),> where the f_i(m) are algebraic integer functions of m and f_0(0) = 1,> f_1(0) = -3, f_2(0) = 0 and f_3(0) = 0?> But the poster fails to point out that his position requires that for> certain values of m and another important variable I call f, that his> f_0(m) *must* have f as a factor, so its basically a step function.> Is that the right word step function?> I think not. I have no idea what you mean with that term. Can you explain> what you mean?> Your position requires that f_0(m) either be a unit or have f as its> only non-unit factor, depending on certain conditions as m varies from> 0 to positive innity.Yes. And so what?Readers should note that the poster admits that his position requiresa function that is either a unit or has f as its only non-unit factordepending on certain conditions as m varies from 0 to positiveinnity. A condition follows. > The condition is that if> a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)> is irreducible over Q, by your position, f_0(m) must have f as its> only non-unit factor.That is correct in part. It must also have f as its only non-unit factor> in some cases when that polynomial *is* reducible. So what?However, do you accept that also for *certain* values of f, like ifthat polynomial is reducible into all linear factors over rationals,that function would be monic?Do you accept that as true?> P(m) = f^2((m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f)> P(m) = (a_1 x + uf)(a_2 x + uf)(a_3 x + uf)> a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).> R(m) = (m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f> R(m) = (b_1 x + u)(b_2 x + u)(b_3 x + uf)> Here reducibility over rationals of the cubic dening the as> a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)> has been given as an issue, and the posters position requires that his> f_0(m) vary such that its 1 if that cubic is reducible over> rationals, and f, if its irreducible over rationals.> See my other post. It is a fallacy. With m=1 and f=2, the polynomial> in a is reducible. The polynomial I come up with is:> 2b^3 + (25 + sqrt(105))/2.b^2 + (-7 + sqrt(105))/2.b - 14.> That looks ok as one of the roots is 1 as required, as one of the bs> is 1.> If it is the correct polynomial, then *each* of the coefcients has 2> as a factor, but NOT in the ring of algebraic integers, as the middle> coefcients are arbitrarily excluded by the denition of algebraic> integers from having 2 as a factor.I am *talking* about the ring of algebraic integers. There are indeed> rings where 2 is a divisor of those two factors. But that is something> completely different. Such rings much more units. So lets say that> there is a ring (the object ring) where (25 + sqrt(105))/4 is in. Why is> (25 - sqrt(105))/4 *not* in that ring? What is the essential difference> between the two?Your intuition, or guesses about the math are not a concern.Im in the process of showing readers just how illogical your positionis by getting you to admit to certain facts that would follow fromyour position.So far its established that you believe that a function is forced tohave f as its only non-unit factor dependent in some way on thereducibility over rationals of the cubica^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)where further Im establishing that you understand that if that cubicis reducible over Q into linear factors that your hypotheticalfunction, called f_0(m) by you, would have to be monic.> Those who doubt that assessment can instead believe in the step> function, which somehow varies the leading coefcient from f to 1> based on whether or not a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)> is reducible over Q.> Note that for the example above, it reduces to a linear and a> quadratic.Yes, and f_0(m) is 2 in that case.Here readers should note the posters belief that the cubic deningthe bs now has a leading term that is 2, which is the value of f,which is consistent with previous positions. > Now theres no *mathematical* way to have a function f_0(m) which will> vary in such an extreme manner depending on whether or not some cubic> is reducible over Q or not, that is consistent with the other> mathematical facts here.Why? I have been thinking about it. It is a fact that f_0(m) is f when> *all three* of the as share a factor with f in the algebraic integers.> In the case above the algebraic integer factors shared are 2,> (-sqrt(7)+sqrt(15))/2 and (-sqrt(7)-sqrt(15))/2. All three non-units> in the algebraic integers. (Note the case f=3 is special as in that> case the constant term of the polynomial is divisible by f^3, and indeed> all three of the as are divisible by f, so f_0(m) = 1, I will not restate> the restriction f != 3 again, and also not the trivial restriction f != 1.)The poster is apparently now trying to come up with a reason for howthis function can jump between 1 and f, in such a peculiar manner.However, the reality is that the ring of algebraic integers does nothave numbers required to keep such oddities from occurring.> Depends on the roots a1 to a3, which two you divide by f, how the resulting> bs can be written as a quotient of an algebraic integer and a normal> integer (in lowest form), and perhaps a bit more. It is *not* possible to> give a general formula. But I have given the algorithm through which you> can calculate that number for each m.> Thats nonsense. Its not necessary to give the expression explicitly> as given that only f is being divided off, it follows that only f can> be the non-unit factor, if there is one.You are not entirely right here. f_0(m) can also be any multiple of f and> any multiple of 1. But when the polynomial is reduced to primitive with> algebraic integer coefcients, it is indeed either 1 or f.Thats not true, and is yet another basic error from this poster.In fact, only f itself is available as a non-unit factor for theleading coefcient of the bs by his position.That he does not know that is just another indication of limitedmathematical understanding from this poster.> Remember, this poster is trying to cast doubt on the factorization> (b_1 x + u)(b_2 x + u)(b_3 x + uf)> which comes from the factorization> (a_1 x + uf)(a_2 x + uf)(a_3 x + uf)> where> (a_1 x + uf)(a_2 x + uf)(a_3 x + uf) = > f^2((m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f)> and the as are given by> a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)> which is a monic with integer coefcients.> ...> which works when m=1, f=sqrt(2), so if you wish to believe this poster> you need to believe in that odd function which varies from being a> unit to having f as a factor dependent on the reducibility of> a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).You state the wrong condition again. f_0(m) = f when the as all three> share a non-unit factor with f, it is 1 otherwise. All three as *can*> share a non-unit factor with f even when the polynomial is reducible.> But lets try it otherwise, to see why this is so. Note that the product> of the factors shared is always f^2.Ive stated the strong condition, which is that if the cubic isirreducible over Q, your claims would require that the leading term ofthe cubic dening the bs is non-monic with f as its only non-unitfactor, which is easier.So far the poster has never given anything like a rational explanationfor why hed suppose itd matter for some cubics that are reducible,while not for others, as I can give m=1, f=sqrt(2), to show a cubicthat is reducible in the same way as his example, where its clearthat only two of the as have algebraic integers, and the cubicdening the bs isb^3 + (1+sqrt(2))b^2 + (sqrt(2)-1)b - 1.Basically the posters position requires a rather odd mathematics withan unexplainable quirkiness.That kind of mathematics sounds like how people are, not how a logicaland consistent system operates.I remind of Ptolemys circles.> This poster either is unwilling to concede to the math, or is> incapable of realizing the aw in his position.Clearly this poster is unwilling to concede to the math and incapable of> realising the aw in his position.The irrationality of believing in a function which jumps in valuesbased on reducibility over rationals is so striking that Ifind itrather interesting that Dik T. Winter is willing to keep debatingabout it.Then again, its kind of interesting to see how long such a poster cango on with such a public display.> The reality is that a function with the behavior he needs doesnt> exist in this context, as his f_0(m) cant vary in the way he needs as> m goes from 0 to positive innity, where it is a unit for certain> values, but switches to having f as its only non-unit factor for> others.*Why* does such a function not exist in this context? That is a pretty> strange argument. Such a function exists independent of context.You *can* have step functions which behave in surprising ways.However, the mathematics here does not allow for the behavior Dik T.Winter claims.mathematical logic.In claiming its validity he has to rely on the aw with thedenition of algebraic integers, which is like trying to walk on abroken leg.> What Im showing here is a outlandish consequence of the posters> position, since this poster and others have continued to argue against> the mathematical argument which shows that the leading coefcient is> always monic as in fact two of the as have a factor that is f, as> shown by their terms independent of m, for all m.The leading coefcient is *not* always 1 when you want algebraic integer> coefcients. And you need algebraic integer coefcients to be able> to tell whether the bs are algebraic integers or not. You can make the> leading coefcient always 1 (trivially so), but in that case you do not> always have all coefcients algebraic integers.Here the poster relies on the broken leg.> You see, m=0 is NOT a special case.Very, very special. Because it has the property that in that case> exactly two of the as are divisible by f for every f, f vanishes> also from the polynomial in a, so the two as that are 0 are trivially> divisible by f. When m != 0 it can be shown that when there are> exactly two of the as divisible by f, that the polynomial in a is> reducible. (The other way around is false.) This has been proven> many times, by various posters, both in general and by specic> examples. Also, when m != 0, f does not vanish from the polynomial> in a.Whats established is that Dik T. Winter believes in this odd andinconsistent function which goes from being a unit to having only f asits non-unit factor in a way that he cant even explain.Hes given an example which he believes has 2 as a leading coefcientwhen in fact all of the coefcients have 2 as a factor, in a properring.James Harris =... > Your position requires that f_0(m) either be a unit or have f as its > only non-unit factor, depending on certain conditions as m varies from > 0 to positive innity. > Yes. And so what? > Readers should note that the poster admits that his position requires > a function that is either a unit or has f as its only non-unit factor > depending on certain conditions as m varies from 0 to positive > innity. A condition follows.Yes, I still see no problem with such a function. The condition is that if > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > is irreducible over Q, by your position, f_0(m) must have f as its > only non-unit factor. > That is correct in part. It must also have f as its only non-unit factor > in some cases when that polynomial *is* reducible. So what? > However, do you accept that also for *certain* values of f, like if > that polynomial is reducible into all linear factors over rationals, > that function would be monic? > Do you accept that as true?Yes, why not? As I have stated: when all as have common factors with fthe leading term of the resulting polynomial will be f. If it reducesto three linear terms over Q, trivially only two as can have common factorsof f, as f is a prime in the integral part of Q (Z). The problem is whenthere are *not* three linear factors. Because in that case not all asare integers, but at least two of them are algebraic integers. And, whilef is prime in the integers, it is not prime in the algebraic integers. > I am *talking* about the ring of algebraic integers. There are indeed > rings where 2 is a divisor of those two factors. But that is something > completely different. Such rings much more units. So lets say that > there is a ring (the object ring) where (25 + sqrt(105))/4 is in. Why is > (25 - sqrt(105))/4 *not* in that ring? What is the essential difference > between the two? > Your intuition, or guesses about the math are not a concern.I have no intuition in the question, not guesses. That is why I pose aquestion. > Im in the process of showing readers just how illogical your position > is by getting you to admit to certain facts that would follow from > your position. > So far its established that you believe that a function is forced to > have f as its only non-unit factor dependent in some way on the > reducibility over rationals of the cubic a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > where further Im establishing that you understand that if that cubic > is reducible over Q into linear factors that your hypothetical > function, called f_0(m) by you, would have to be monic.Yes. I still see no problem. There are stranger functions in mathematics. > Those who doubt that assessment can instead believe in the step > function, which somehow varies the leading coefcient from f to 1 > based on whether or not > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > is reducible over Q. > Note that for the example above, it reduces to a linear and a > quadratic. > Yes, and f_0(m) is 2 in that case. > Here readers should note the posters belief that the cubic dening > the bs now has a leading term that is 2, which is the value of f, > which is consistent with previous *mathematical* way to have a function f_0(m) which will > vary in such an extreme manner depending on whether or not some cubic > is reducible over Q or not, that is consistent with the other > mathematical facts here. > Why? I have been thinking about it. It is a fact that f_0(m) is f when > *all three* of the as share a factor with f in the algebraic integers. > In the case above the algebraic integer factors shared are 2, > (-sqrt(7)+sqrt(15))/2 and (-sqrt(7)-sqrt(15))/2. All three non-units > in the algebraic integers. (Note the case f=3 is special as in that > case the constant term of the polynomial is divisible by f^3, and indeed > all three of the as are divisible by f, so f_0(m) = 1, I will not restate > the restriction f != 3 again, and also not the trivial restriction f != 1.) > The poster is apparently now trying to come up with a reason for how > this function can jump between 1 and f, in such a peculiar manner.There are enough functions that jump up and down. So what? Her we haveanother function. > However, the reality is that the ring of algebraic integers does not > have numbers required to keep such oddities from occurring.The ring of algebraic integers does indeed not have numbers jumping up anddown. But we were talking about a function. > Thats nonsense. Its not necessary to give the expression explicitly > as given that only f is being divided off, it follows that only f can > be the non-unit factor, if there is one. > You are not entirely right here. f_0(m) can also be any multiple of f and > any multiple of 1. But when the polynomial is reduced to primitive with > algebraic integer coefcients, it is indeed either 1 or f. > Thats not true, and is yet another basic error from this poster. > In fact, only f itself is available as a non-unit factor for the > leading coefcient of the bs by his position.Eh? Given the polynomial (x - 1) which has the root x = 1, so the leadingcoefcient is 1. (2x - 2) has the same root, as has (3x - 3). Youprimitive in the paragraph above. > That he does not know that is just another indication of limited > mathematical understanding from this poster.That he does not know that is just another indication of limitedreading capabilities from this poster. > You state the wrong condition again. f_0(m) = f when the as all three > share a non-unit factor with f, it is 1 otherwise. All three as *can* > share a non-unit factor with f even when the polynomial is reducible. > But lets try it otherwise, to see why this is so. Note that the product > of the factors shared is always f^2. > Ive stated the strong condition, which is that if the cubic is > irreducible over Q, your claims would require that the leading term of > the cubic dening the bs is non-monic with f as its only non-unit > factor, which is easier. > So far the poster has never given anything like a rational explanation > for why hed suppose itd matter for some cubics that are reducible, > while not for others, as I can give m=1, f=sqrt(2), to show a cubic > that is reducible in the same way as his example, where its clear > that only two of the as have algebraic integers, and the cubic > dening the bs isI thought all the time that f was integral? Even prime? > b^3 + (1+sqrt(2))b^2 + (sqrt(2)-1)b - 1. > Basically the posters position requires a rather odd mathematics with > an unexplainable quirkiness.What is odd about it, what is a quirkiness? > This poster either is unwilling to concede to the math, or is > incapable of realizing the aw in his position. > Clearly this poster is unwilling to concede to the math and incapable of > realising the aw in his position. > The irrationality of believing in a function which jumps in values > based on reducibility over rationals is so striking that Ifind it > rather interesting that Dik T. Winter is willing to keep debating > about it.You believe such a function does not exist? Please sleep on. > The reality is that a function with the behavior he needs doesnt > exist in this context, as his f_0(m) cant vary in the way he needs as > m goes from 0 to positive innity, where it is a unit for certain > values, but switches to having f as its only non-unit factor for > others. > *Why* does such a function not exist in this context? That is a pretty > strange argument. Such a function exists independent of context. > You *can* have step functions which behave in surprising ways. > However, the mathematics here does not allow for the behavior Dik T. > Winter claims.Can you *please* tell us why such a function is not allowed her? > In claiming its validity he has to rely on the aw with the > denition of algebraic integers, which is like trying to walk on a > broken leg.The broken leg is yours. You just *want* that exactly two of the asare not co-prime to f. When it is shown that such is not possible inthe algebraic integers you just go away. > The leading coefcient is *not* always 1 when you want algebraic integer > coefcients. And you need algebraic integer coefcients to be able > to tell whether the bs are algebraic integers or not. You can make the > leading coefcient always 1 (trivially so), but in that case you do not > always have all coefcients algebraic integers. > Here the poster relies on the broken leg.Did I not show that is not possible in the algebraic integers, and justbecause you *whish* it to be true you are trying to go to another ring,Where is the broken leg? > Very, very special. Because it has the property that in that case > exactly two of the as are divisible by f for every f, f vanishes > also from the polynomial in a, so the two as that are 0 are trivially > divisible by f. When m != 0 it can be shown that when there are > exactly two of the as divisible by f, that the polynomial in a is > reducible. (The other way around is false.) This has been proven > many times, by various posters, both in general and by specic > examples. Also, when m != 0, f does not vanish from the polynomial > in a. > Whats established is that Dik T. Winter believes in this odd and > inconsistent function which goes from being a unit to having only f as > its non-unit factor in a way that he cant even explain.You state inconsisten. Inconsistent with what exactly? > Hes given an example which he believes has 2 as a leading coefcient > when in fact all of the coefcients have 2 as a factor, in a proper > ring.Ah. So you do not falsify my statements at all. What you imply here isthat I was correct, but you wish to move to another ring. Fine. Pleasestate the denition of the ring *such that it can be determined whethera particular number belongs to the ring or not*. As long as you have notdone the latter, you have no ring.So much verbiage by James to simply state: you are correct, but you arenot working in the ring where I am working.-- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/ ...> Your position requires that f_0(m) either be a unit or have f as its> only non-unit factor, depending on certain conditions as m varies from> 0 to positive innity.> Yes. And so what?> Readers should note that the poster admits that his position requires> a function that is either a unit or has f as its only non-unit factor> depending on certain conditions as m varies from 0 to positive> innity. A condition follows.Yes, I still see no problem with such a function.Then give a *single* function in ALL of mathematics which behaves asyou wish.Youre making up some wacky mathematics.For readers who havent kept up, this poster needs a function which isa unit whena^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)is fully reducible into all linear factors over rationals, which has acomplex (and so far unexplained) behavior when its reducible into alinear and a quadratic, where sometimes its unit or else it has onlyf as a non-unit factor, which would always have f as a non-unit factorifa^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)is irreducible over rationals. The condition is that if> a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)> is irreducible over Q, by your position, f_0(m) must have f as its> only non-unit factor.> That is correct in part. It must also have f as its only non-unit factor> in some cases when that polynomial *is* reducible. So what?> However, do you accept that also for *certain* values of f, like if> that polynomial is reducible into all linear factors over rationals,> that function would be monic?> Do you accept that as true?Yes, why not? As I have stated: when all as have common factors with f> the leading term of the resulting polynomial will be f. If it reduces> to three linear terms over Q, trivially only two as can have common factors> of f, as f is a prime in the integral part of Q (Z). The problem is when> there are *not* three linear factors. Because in that case not all as> are integers, but at least two of them are algebraic integers. And, while> f is prime in the integers, it is not prime in the algebraic integers.Huh? It looks like the poster conceded that if a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m)is reducible over rationals into all linear factors that his positionis bogus.No reason is given. Then the poster basically babbles at the end.Yes, f is prime in the integers and not prime in algebraic integers,but that has no relevance here.Its kind of interesting to watch this person jump, dance and dovarious gyrations as he tries to shoehorn mathematics.Lets see what else interesting comes from him.James Harris =... > Yes. And so what? > Readers should note that the poster admits that his position requires > a function that is either a unit or has f as its only non-unit factor > depending on certain conditions as m varies from 0 to positive > innity. A condition follows. Yes, I still see no problem with such a function. > Then give a *single* function in ALL of mathematics which behaves as > you wish. > Youre making up some wacky mathematics.Oh, come on. Do you know the Moebius function? mu(n) = 1 if n = 1 0 if n is divisible by a square (-1)^r if n = the product of r distinct primes.Wacky enough? But indeed, not the function we seek, see below. > For readers who havent kept up, this poster needs a function which is > a unit when > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > is fully reducible into all linear factors over rationals, which has a > complex (and so far unexplained) behavior when its reducible into a > linear and a quadratic, where sometimes its unit or else it has only > f as a non-unit factor, which would always have f as a non-unit factor > if > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > is irreducible over rationals.f_0(m,f) = f if f != 3 and all three roots of the polynomial are not co-prime to f = 1 otherwise. > However, do you accept that also for *certain* values of f, like if > that polynomial is reducible into all linear factors over rationals, > that function would be monic? > Do you accept that as true? > Yes, why not? As I have stated: when all as have common factors with f > the leading term of the resulting polynomial will be f. If it reduces > to three linear terms over Q, trivially only two as can have common factors > of f, as f is a prime in the integral part of Q (Z). The problem is when > there are *not* three linear factors. Because in that case not all as > are integers, but at least two of them are algebraic integers. And, while > f is prime in the integers, it is not prime in the algebraic integers. > Huh? It looks like the poster conceded that if > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) > is reducible over rationals into all linear factors that his position > is bogus.What is the contradiction with my position? > No reason is given. Then the poster basically babbles at the end.A pity you cant follow it. If the cubic splits in linear terms over Q,the three roots are integer. Because the product of the roots is amultiple of f^2, with f prime, at most two of the as are co-prime to f(note again: the as are integer in this case). So f_0(m) = 1 in thiscase. > Yes, f is prime in the integers and not prime in algebraic integers, > but that has no relevance here.Well, that is crucial, you know. If *not* all three are integer, but atleast two of them are algebraic integer it is possible that all *three*are not co-prime to f, just because f is not a prime in the algebraicintegers. Capisce? > Its kind of interesting to watch this person jump, dance and do > various gyrations as he tries to shoehorn mathematics.I see gyrations, but not by me I am afraid.-- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/ ... Yes. And so what?> Readers should note that the poster admits that his position requires> a function that is either a unit or has f as its only non-unit factor> depending on certain conditions as m varies from 0 to positive> innity. A condition follows.> Yes, I still see no problem with such a function.> Then give a *single* function in ALL of mathematics which behaves as> you wish. Youre making up some wacky mathematics.Oh, come on. Do you know the Moebius function?> mu(n) = 1 if n = 1> 0 if n is divisible by a square> (-1)^r if n = the product of r distinct primes.> Wacky enough? But indeed, not the function we seek, see below.> Ive found a simpler refutation of this posters position.Remember I haveP(m) = f^2((m^3 f^4 - 3m^2 f^2 + 3m) x^3 - 3(-1+mf^2 )x u^2 + u^3 f) Variables: m, f, x, u E Ring of Algebraic integersand the factorization P(m) = (a_1(m) x + uf)(a_2(m) x + uf)(a_3(m) x + uf) Variables: a_1, a_2, a_3, roots of cubic dened as follows. Cubic: a^3 + 3(-1+mf^2)a^2-f^2(m^3 f^4 - 3m^2 f^2 + 3m)The poster wishes for a variable function which has the property ofbeing a factor of f, so Ill use w_1(m) w_2(m) w_3(m) = f^2, where a_1has w_1(m) as a factor for all integer m.Then a_1(m) x + uf must have w_1(m) as a factor, so dividing throughgivesa_1(m)/w_1(m) + uf/w_1(m)where uf/w_1(m) cant be an algebraic integer for all integer m.It might help for me to put in actual numbers for u and f, which I cando as the variables are independent of each other, so let u=2, f=7,then itsa_1(m)/w_1(m) + 14/w_1(m)and clearly, if w_1(m) varies with m, then 14/w_1(m) is not analgebraic integer for all integer m.For those who STILL need help, consider that if you had 14/w_1(m) = r(m)introducing r(m) for the result of the division, thenw_1(m) r(m) = 14sow_1(m) r(m) - 14 = 0which would force zeroes for m.That is, you cant have algebraic integer functions, that is functionsthat give algebraic integer results, and not have only certain valuesof m that would work.That is, you can have something like 2m+ 7 = 21, that works for aparticular value of m, but you cant have functions in algebraicintegers that will multiply to give 14 for all integer m.To get such functions, you have to go outside the ring into a eld.That refutes the position of Dik T. Winter, and note that as Ivepointed out that poster clearly either has limited mathematicalability, or hes been lying now for some time.James Harris ...>b^3 + 3(-1+mf^2)b^2 - (m^3 f^4 - 3m^2 f^2 + 3m),> This is not correct. Note that a1/f = b1, or a1 = f*b1.> Putting this into the equation above that the as> satisfy and simplifying, one obtains> f*b1^3 + 3*(-1 + m*f^2)*b1^2 - (m^3*f^4 - 3*m^2*f^2 + 3*m).> Clearly b2 is a root of the same polynomial. Since > b3 = a3, b3 satises a different equation:> b3^3 + 3*(-1+mf^2)b3^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m) = 0.> Um, Nora Baron do you accept that there exists a SINGLE cubic which> has the bs as its roots?> Nora Baron *only* state that the single cubic you give is not one which> has the bs as its roots.> Um, do *you* accept that there exists a SINGLE cubic which has the bs> as its roots?> Yes, I do, and I think everyone does. (x-b1)(x-b2)(x-b3) serves just ne.> It is a cubic in b, but as the bs depend on m, it is not necessarily a> cubic in m.The question is to the solution for the bs, just like earlier in the> post a solution for the as is given as they are roots of the cubic(***) a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).> This entire argument can be shortened even further thanI thought. Look at the polynomial (***) in a just above.We all agree that it is correct. Harris says that at least one of the roots is divisible by f. So let a = f*c (where c is an A.I.) and substitute that into (***): f^3*c^3 + 3(-1+mf^2)f^2*c^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m). Factor out f^2: f*c^3 + 3(-1+mf^2)c^2 - (m^3 f^4 - 3m^2 f^2 + 3m).Let m = 1 and f = 5 and set the expression to zero: 5*c^3 + 72*c^2 - 553 = 0Its nonmonic, primitive, and irreducible. Thereforec is NOT an A.I. Therefore NO root of {***} is divisible by f = 5. No need to worry about whether you need one or twocubics for the bs. No complications. Totally directand simple, and totally irrefutable. Harris, I bet you remember that scene in The Matrix where Cary-Ann Moss puts a gun right against the head of an Agent, and says: Dodge The question is to the solution for the bs, just like earlier in the> post a solution for the as is given as they are roots of the cubic>(***) a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).> This entire argument can be shortened even further than> I thought. Look at the polynomial (***) in a just above.> We all agree that it is correct. Harris says that at least > one of the roots is divisible by f. So let a = f*c (where > c is an A.I.) and substitute that into (***): f^3*c^3 + 3(-1+mf^2)f^2*c^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).> Factor out f^2: f*c^3 + 3(-1+mf^2)c^2 - (m^3 f^4 - 3m^2 f^2 + 3m).Let m = 1 and f = 5 and set the expression to zero: 5*c^3 + 72*c^2 - 553 = 0Its nonmonic, primitive, and irreducible. Therefore> c is NOT an A.I. Therefore NO root of {***} is > divisible by f = 5.Aha! Core error! Youve found one of the missing numbers.Obviously, c isnt in the algebraic integers, butit SHOULD BE!!!(As a matter of fact, I think that this is what Jamesshould test is: If it would make his argument work forsome x to be an algebraic integer, then it should beone. And by James logic, he has therefore proved that it is. So when you show that it isnt, thats a contradiction in core.) - Randy The question is to the solution for the bs, just like earlier in the> post a solution for the as is given as they are roots of the cubic>(***) a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).> This entire argument can be shortened even further than> I thought. Look at the polynomial (***) in a just above.> We all agree that it is correct. Harris says that at least > one of the roots is divisible by f. So let a = f*c (where > c is an A.I.) and substitute that into (***):> f^3*c^3 + 3(-1+mf^2)f^2*c^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).> Factor out f^2:> f*c^3 + 3(-1+mf^2)c^2 - (m^3 f^4 - 3m^2 f^2 + 3m).> Let m = 1 and f = 5 and set the expression to zero:> 5*c^3 + 72*c^2 - 553 = 0> Its nonmonic, primitive, and irreducible. Therefore> c is NOT an A.I. Therefore NO root of {***} is > divisible by f = 5.Aha! Core error! Youve found one of the missing numbers.> Obviously, c isnt in the algebraic integers, but> it SHOULD BE!!!(As a matter of fact, I think that this is what James> should test is: If it would make his argument work for> some x to be an algebraic integer, then it should be> one. And by James logic, he has therefore proved that > it is. So when you show that it isnt, thats a > contradiction in core.)> Randy, That is his general modus operandi. In this casehowever the polynomial {***} is his own creation. It is a somewhat Procrustean stretch to have somethingthat you have used as the basis for a proof turn out tobe exactly the basis for a DISproof of exactly the samething. How can you attack your own polynomial? He has not responded to my posts for several days. No doubt he will maintain that I cheat and lie,and I must be worse at it than Arturo and Dik Winter because he is on speaking terms with them. Youcan see for yourself in my post that it is chock fullof cheating and lying. As for the idea that c should be an algebraic integer: he has described the algebraic integers asincomplete. I think this is based on Einsteinsdescription of quantum theory as incomplete - Einstein believed (without proof) that local hiddenvariables must be present which would resolve problemslike quantum entanglement and eliminate the uncertaintyprinciple. Physics would be determinate rather thanprobabilistic on the small scale. However later developments in theory (Bells theorem) and experiments indicated thatEinstein was wrong [though some physicists and a largernumber of cranks still disagree]. But for Harriss situation, this harking back to Einsteinwould be gilding the lily. Harriss result, claiming that cSHOULD be an algebraic integer or MUST be one, does not lead one to think that the algebraic integers are incomplete. It simply at out contradicts a known theorem. There are reallyonly three possibilities: 1. The known theorem is wrong [but Harris has accepted it as correct some time ago; it goes back to Gauss]. 2. Mathematics is inconsistent [Harris rejects that idea]. 3. Harriss argument is wrong. There is no room for any other choices. I have my own opinion on this which you can no doubt guess. Nora B.> - Randy =... > The reason is that posters like this one have worked to convince > readers of mathematically false things, and I can show that their > assertions would force the cubic that has the bs for roots to be > *selectively* non-monic, where if they are correct, the cubic has to > be non-monic if > a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m). > is irreducible over Q, and monic if its not. > Lessee whether that is true. Lets take m = 1, f = 2. The polynomial > becomes: > a^3 + 9.a^2 - 28, > this one is reducible: (a + 2)(a^2 + 7a - 14). Nevertheless, every > polynomial with integer coefcients that denes the bs is not monic, > because the bs are not all algebraic integers. So your claim is false.Let me elaborate. With m=1, f=2 the polynomial in a is written as above.The three roots are (sqrt meaning the positive square root of an integer): a1 = -2 a2 = [-7 + sqrt(105)]/2 = sqrt(7).r2 a3 = [-7 - sqrt(105)]/2 = sqrt(7).r3where r2 and r3 are: r2 = [-sqrt(7) + sqrt(15)]/2 r3 = [-sqrt(7) - sqrt(15)]/2.Now r2 and r3 are algebraic integers (they are roots of the polynomialx^4 - 11.x^2 + 4, the other two roots have the sign of sqrt(7) inverted),moreover, r2.r3 = 2, so they are both divisors of 2. a1 shares thefactor 2 with f(=2), a2 shares the factor r2 with f and a3 shares thefactor r3 with f. Now b1 (= a1/f) and b3 (= a3) are algebraic integers,b2 (= a2/f) is not. So there is no monic cubic polynomial with integercoefcients that has all three of b1 to b3 as root, because that wouldmake b2 an algebraic integer. > Yes. Do you want a proof?About the proof that every algebraic number can be written as the quotientof an algebaric integer and a normal integer. I *think* it can be madestronger (here follows a conjecture, WLT): Lets have P(x) an irreducible, primitive polynomial with integer coefcients. Let a be the leading coefcient of the polynomial and let b be a root.Then: a.b is an algebraic integer (that is easy) and (a.b,a) = 1 in the algebraic integers (that is hard).I will think about it.-- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/ ...> The reason is that posters like this one have worked to convince> readers of mathematically false things, and I can show that their> assertions would force the cubic that has the bs for roots to be> *selectively* non-monic, where if they are correct, the cubic has to> be non-monic if> a^3 + 3(-1+mf^2)a^2 - f^2(m^3 f^4 - 3m^2 f^2 + 3m).> is irreducible over Q, and monic if its not.> Lessee whether that is true. Lets take m = 1, f = 2. The polynomial> becomes:> a^3 + 9.a^2 - 28,> this one is reducible: (a + 2)(a^2 + 7a - 14). Nevertheless, every> polynomial with integer coefcients that denes the bs is not monic,> because the bs are not all algebraic integers. So your claim is false.Now readers whove kept up realize that my point is that the ring ofalgebraic integers is awed because of the denition of algebraicinteger, so you should be surprised at this poster attempting to relyon the denition of algebraic integers.But besides that please pay attention to the full claim, whichrequires that the polynomial--a cubic--that has the bs as roots havea leading coefcient that switches from being monic to having f asits only non-unit factor depending on the cubic dening the as beingreducible over rationals.The poster requires a complex relationship where sometimes if thecubic for the as is reducible into a linear and a quadratic the cubicis monic, while in others, its not, while the posters position wouldrequire that its never monic if the cubic dening the as isirreducible over Q.Let me elaborate. With m=1, f=2 the polynomial in a is written as above.> The three roots are (sqrt meaning the positive square root of an integer):> a1 = -2> a2 = [-7 + sqrt(105)]/2 = sqrt(7).r2> a3 = [-7 - sqrt(105)]/2 = sqrt(7).r3> where r2 and r3 are:> r2 = [-sqrt(7) + sqrt(15)]/2> r3 = [-sqrt(7) - sqrt(15)]/2.> Now r2 and r3 are algebraic integers (they are roots of the polynomial> x^4 - 11.x^2 + 4, the other two roots have the sign of sqrt(7) inverted),> moreover, r2.r3 = 2, so they are both divisors of 2. a1 shares the> factor 2 with f(=2), a2 shares the factor r2 with f and a3 shares the> factor r3 with f. Now b1 (= a1/f) and b3 (= a3) are algebraic integers,> b2 (= a2/f) is not. So there is no monic cubic polynomial with integer> coefcients that has all three of b1 to b3 as root, because that would> make b2 an algebraic integer. > Yes. Do you want a proof?Thats the posters on question from the prior post. Hes replying tohimself in what follows, I guess, unless hes ignoring his ownquestion!!! > About the proof that every algebraic number can be written as the quotient> of an algebaric integer and a normal integer. I *think* it can be made> stronger (here follows a conjecture, WLT):> Lets have P(x) an irreducible, primitive polynomial with integer> coefcients. Let a be the leading coefcient of the polynomial and> let b be a root.> Then:> a.b is an algebraic integer (that is easy) and> (a.b,a) = 1 in the algebraic integers (that is hard).> I will think about it.I remind of the position this poster needs, which is that the cubicdening the bs has a leading coefcient that varies from being aunit to having f as its only non-unit factor dependent, on the cubicdening the as, where supposedly reducibility over rationals is thebig deal.When pushed the poster starts making claims about proving thatotherwise the coefcients arent algebraic integers, when my pointfor some time has been that the denition of algebraic integers isawed.The correct answer is that the cubic dening the bs is always monic,and for certain values of m and f, its coefcients are pushed out ofthe ring of algebraic integers because the denition is awed byexcluding certain numbers, which you can see need to be included, oryou get contradictions.James Harris =... > The correct answer is that the cubic dening the bs is always monic, > and for certain values of m and f, its coefcients are pushed out of > the ring of algebraic integers because the denition is awed by > excluding certain numbers, which you can see need to be included, or > you get contradictions.As I have written already multiple times, it is trivially monic in otherrings, the cubic (x - b1)(x - b2)(x - b3) serves just ne. But youwant to go to a ring where your divisibility claims work. It includesthe ring of algebraic integers. But which of the two numbers (-sqrt(7) + sqrt(15))/2 and (-sqrt(7) - sqrt(15))is a unit in that ring? And why precisely that number? How can wedetermine whether a number is in that ring or not? As long as youdo not give a clear indication on how to determine the numbers inthat ring it is not possible to know whether the division requirementsyou need are indeed in that ring.You have also not yet shown what the contradiction is.-- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/ ...> The correct answer is that the cubic dening the bs is always monic,> and for certain values of m and f, its coefcients are pushed out of> the ring of algebraic integers because the denition is awed by> excluding certain numbers, which you can see need to be included, or> you get contradictions.>>As I have written already multiple times, it is trivially monic in other>rings, the cubic (x - b1)(x - b2)(x - b3) serves just ne. But you>want to go to a ring where your divisibility claims work. It includes>the ring of algebraic integers. But which of the two numbers> (-sqrt(7) + sqrt(15))/2 and (-sqrt(7) - sqrt(15))>is a unit in that ring? And why precisely that number?James situation gets a bit more complicated than that; I explained itto him, but as he usually does with uncomfortable truths, he justignored it and started repeating his claim again.Assume that (-sqrt(7)+sqrt(15))/2 is a unit in the ring. Then so isits square,(22 -2sqrt(105))/4 = (11-sqrt(105))/2.This element is a root of x^2 - 11x + 4.So if this is a unit, that means that the ring contains one root ofthe irreducible quadratic polynomial 4x^2 - 11x + 1.James has never told us whether, if an irreducible polynomial has aroot in his ring, does it have all roots in his ring? Because heclaims that his denition xes the algebraic integers, by allowingnumbers that had been excluded, it seems reasonable to assume thatit does. But of course he has never come out and said it straight.So, since it has a root of 4x^2-11x+1, should it not contain the otherroot as well? The other root is the inverse of (11+sqrt(105))/2. Butthis is the square of (-sqrt(7)-sqrt(15))/2; so (-sqrt(7)-sqrt(15))/2is also a unit in the ring. Which would mean they BOTH are units inthe ring, which would mean that their product, 2 is a unit, which weknow cannot be true.Ah, so it must be that (-sqrt(7)+sqrt(15))/2 is not a unit in thering. So it must be that it is (-sqrt(7)-sqrt(15))/2 that is aunit. So its square, (11+sqrt(105))/2 is a unit; so the ring containsa root of 4x^2 - 11x + 1; so it contains both roots; so it containsthe inverse of (11-sqrt(105))/2. So (-sqrt(7)+sqrt(15))/2 is aunit. Oops.Which leaves us with two possibilities:(A) The Object ring does not satisfy the properties James claimseither: in that ring, neither (-sqrt(7)-sqrt(15))/2 nor(-sqrt(7)+sqrt(15))/2 are units;or(B) In the Object ring, this marvellous construction that xes thering of algebraic integers by allowing numbers that should be in,there are polynomias with integer coefcients, irreducible over Q,which have ->SOME<- roots in the ring but not all of them.And in case (B), how do we know which one is there, as you ask? reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can criticize. A great many people are staggered to this extent, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de Morgan >As I have written already multiple times, it is trivially monic in other >rings, the cubic (x - b1)(x - b2)(x - b3) serves just ne. But you >want to go to a ring where your divisibility claims work. It includes >the ring of algebraic integers. But which of the two numbers > (-sqrt(7) + sqrt(15))/2 and (-sqrt(7) - sqrt(15)) >is a unit in that ring? And why precisely that number?... > (B) In the Object ring, this marvellous construction that xes the > ring of algebraic integers by allowing numbers that should be in, > there are polynomias with integer coefcients, irreducible over Q, > which have ->SOME<- roots in the ring but not all of them. > And in case (B), how do we know which one is there, as you ask?I think (B) is indeed precisely the case. James wants all those numbersin his ring such that the cubics in the bs are monic with numbers inhis rings for all possible polynomials P(m). So when we look at thepolynomial in a for m=1 and f=2 we get (in the algebraic integers)three roots that are obviously not coprime to f. To get at his claimthat exactly *one* of the as is coprime to f he has to make one ofthose common factors (that I have written above) units. They are bothroots of an irreducible polynomial with integer coefcients of degree 4.Actually sometime ago he made a remark that suggested this.The main problem is that he has to make this choice for each and everypolynomial that comes up. Now I am not sure, but it may be possibleto have a ring where only a single root of a quadratic is in his ring,I very much doubt that a choice can be made across *all* polynomialshe comes up with without getting conicts. He has to show that aconsistent choice can be made.-- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/ answer is that the cubic dening the bs is always monic,> and for certain values of m and f, its coefcients are pushed out of> the ring of algebraic integers because the denition is awed by> excluding certain numbers, which you can see need to be included, or> you get contradictions.>> James HarrisThere is no aw in the denition of algebraic integers and no contradiction in any results obtained byvalid operations. There is an error in your argument.--A fool and his proof are soon refuted.--Democracy: The triumph of popularity over principle.--http://www.crbond.com =Given a kxk diagonal matrix, under what conditions we can ensure the matrix is positive denite?Alos, if the matrix is not diagonal with all the elements are positive real number, how can we ensure it is positive denite?Willy =Given a kxk diagonal matrix, under what conditions we can ensure the matrix is positive > denite?The matrix is positive denite if and only if all entries are >0(this is easy to see, make use of the canonical basis to proof this)Alos, if the matrix is not diagonal with all the elements are positive real number, how > can we ensure it is positive denite?> There is a very useful subdeterminant criterion for symmetric (resp.hermitian) matrices (elements need not all be >0 to use this test):check the number in the upper left corner. For the matrix to bepositive denite, it must be positive. In the same way, check thedeterminant of the 2x2-matrix in the upper left, then thecorresponding 3x3-matrix, etc. If all these determinants are positive(including the last determinant which is that of the whole matrix),then the matrix is pos. def..The converse is also true.It may save much computational work if you permute the rows andcolumns in the matrix before applying the criterion so thatcalculation of the determinants is as easy as possible. >Given a kxk diagonal matrix, under what conditions we can ensure the matrix>is positive >denite?>>Alos, if the matrix is not diagonal with all the elements are positive real>number, how >can we ensure it is positive denite?>Willy>>If youre looking to check, look up Sylvesters criterion.There are many other special cases. For example, diagonally dominant matriceswith positive diagonal entries.--irascible since 1957 =Can anyone please point me toward an implementation (in any language, evenpseudo ones) of Knuths spectral test?I have a random generator that I need to test, and I can not ndimplementations of the test...(I have found implementation specially geared for congrual tests, but thisis not what I need as my generator is not congrual). =Note subject change.In sci.math, Justin Davis<5bfec9e3.0310150545.5bdf3dfd@ :>> [snip for brevity]> Does it matter? Given any nite digit sequence, pi embeds it.>> Somewhere. :-)>> (At least, such is my understanding.) Im afraid I dont understand your understanding.> I can try to be more precise, if it will help. Consider a sequence D_0, D_1, ... D_{k-1}, for some>> integer k > 0, where D_i is in the set of digits>> {0,1,2,3,4,5,6,7,8,9}. Then consider the sequence P_0,>> P_1, ... where P_i = oor(pi * 10^i) mod 10. Therefore>> P_0 = 3, P_1 = 1, P_2 = 4, P_3 = 1, P_4 = 5, P_5 = 9,>> etc., or more compactly and familiarly written pi = 3.14159... The idea is that there exists an N such that P_N = D_0,>> P_{N+1} = D_1, P_{N+2} = D_2, ... , P_{N+k-1} = D_{k-1},>> given the sequence D_0 to D_{k-1}. I hesitate to call it a theorem as Ive no idea how to>> prove it. (Im not even sure Im formulating it correctly,>> although I suspect it is true.) Its obvious pi is irrational, but so are the>> numbers 0.121121112111121111121111112.... and>> 0.345334455333444555333344445555... . Theres>> no 6 in either one. If you dont like base 10 you can of course modify the>> digit denitions appropriately. :-)I think the property youre looking for is normality. Pi would be> normal in base 10 if the above were true. Look> http://pi314.at/math/normal.html for a more in-depth notehttp://mathworld.wolfram.com/NormalNumber.html(an obvious search for those familiar with mathworld.wolfram.com).Evidently the problems not quite as cut and dried as I thought, andlooks like an open question.-- #191, ewill3@earthlink.netIts still legal to go .sigless. =Regarding Grahams number,here is a diagram that Ive seen on the web- / 1) 3^^^^3 | | 2) 3^^...1)...^^3 [where there are 1) = 3^^^^3up-arrows] | | 3) 3^^...2)...^^3 [where there are 2) up-arrows] | . 64 levels < . | . | . | 63) 3^^...62)...^^3 | 64) 3^^...63)...^^3 <--- Grahams #(-the process of so and so many arrows is far from beingmathematicallyprecise and needs to be reworked;however,it lends itself to beingspaciallycompact. :-) )Labelling sections and bays one section ________________^_______ | / | 2 bays | ______________^_________ | / | bay 1 bay 2 | ___^___ ______^________ | / / > one section / 1) 3^^^^3 | | 2) 3^..1)..^3 | | 3) 3^..2)..^3 | 64 levels< . | | . | | . | 64) 3^..63)..^3 /where a bay (OL) includes all levels and a section is all bays andtheir levels.Using this mechanism, the Conway-Guy expression a -> b -> ..... x -> y -> zcan be dened in terms of Knuth up-arrows, e.g. 2->3->3->4 8 bays __________________________________^__________________________ __________/ bay 1 bay 2 bay 3 4-7 bay 8 __^___ _________^__________ __________^_________ __^__ _____^______/ / / / / / 1) 2^3 = 8 / 1) 2^3 / / 1) 2^3 | 2) 2^..1)..^3 | 2) 2^..1)..^3 | | 2)2^..1)..^3 | 3) 2^..2)..^3 | . | | .8 levels< . | . | 4 | . | . | . | bays| . 8) 2^..7)..^3 levels< . |here | . = 2->3->8->2 | . | | . = 2->3->2->3 ..2^........^3 levels<.....< . = 2->3->3->3 | | . ..2^........^3 = 2->3->8->3 bays = 2->3->2->4 _____________________________________________________________ ____^_____/ / 1) 2^3 / 1) 2^3 / / 1) 2^3 | . | . | | .8 levels< . | . | | . | . | . | | . 8) 2^..7)..^3 levels< . | | . | . | | . ..2^........^3 levels<.....< . | | . ..2^........^3 =2->3->3->4the above can be called 2 section levelscrunch the diagram down to this;dropping bays # 1 and 3 --- 7 bays ___________^_____________ / 1) 2^3 / / 1) 2^3 . | | . . | | . 8)2^..7)..^3<..< . levels | | . ..2^.....^3 = 2->3->2->4 bays ___________________^_____ /1) 2^3 / / 1) 2^3 . | | . . | | . 8)2^..7)..^3<..< . levels| | . ..2^.....^3 = 2->3->3->4Following and extending the concept---> another try at 9->9->9->9--- 387420488 section bays> _______________________________________________^_____________ ________________________________________________ > / > / 387420488 bays > | _______________________^_____________________ > |/ 1) 9^9=387420489 / / 1) 9^9 > | 2) 9^..1)..^9 | | 2) 9^..1)..^9 > | . | | . > | . | | . > |387420489) 9^..387420488)..^9<..< . > | levels| | . > | ..9^........^9 > | bays > /387420488< ______________________________________^______ > | section|/ . > | levels | . / / 387420488 bays > | | . | | _______________________^_____________________ > | | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 > | |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 > | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . > | | . | | . | | . | | . > | | . | | . | |387420489) 9^..387420488)..^9<..< . > | |387420489) 9^..387420488)..^9<..< . | | levels| | . > | | levels | | . | | ..9^........^9 > | ..9^.........^9<...< bays > | section levels | | ___________________________________^_________ > | | |/ . > | | | . > | | | ___________________________________^_________ > | | |/ 1) 9^9 / / 1) 9^9 > | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 > 387420488< | | . | | . > levels of| | | . | | . > section | | |387420489) 9^..387420488)..^9<..< . > levels | | | levels | | . > | ..9^........^9 > | section bays > | _____________________________________________________________ _____________________________________^_________ > |/ . > | . > | _____________________________________________________________ _____________________________________^_________ > |/ / 387420488 bays > | | _______________________^_____________________ > | |/ 1) 9^9=387420489 / / 1) 9^9 > | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 > | | . | | . > | | . | | . > | |387420489) 9^..387420488)..^9<..< . > | | levels| | . > | | ..9^........^9 > | | bays > 387420488< ______________________________________^______ > section|/ . > levels | . / / 387420488 bays > | . | | _______________________^_____________________ > | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 > |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 > | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . > | . | | . | | . | | . > | . | | . | |387420489) 9^..387420488)..^9<..< . > |387420489) 9^..387420488)..^9<..< . | | levels| | . > | levels | | . | | ..9^........^9 > ..9^.........^9<...< bays > section levels | | ___________________________________^_________ > | |/ . > | | . > | | ___________________________________^_________ > | |/ 1) 9^9 / / 1) 9^9 > | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 > | | . | | . > | | . | | . > | |387420489) 9^..387420488)..^9<..< . > | | levels | | . > ..9^........^9 > levels of > 387420488 bays of section bays section levels > _____________________________________________________________ __^___________________________________________________ |> / v> v> 387420488 section bays v> _____________________________________________________________ __^____________________________________________ | | v> / | | v> / 387420488 bays | | v> | _______________________^_____________________ | | v> |/ 1) 9^9=387420489 / / 1) 9^9 | | v> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | v> | . | | . | | v> | . | | . | | v> |387420489) 9^..387420488)..^9<..< . | | v> | levels| | . | | v> | ..9^........^9 | | v> | bays | | v> 387420488< ______________________________________^______ | | v> section|/ . | | v> levels | . / / 387420488 bays | | v> | . | | _______________________^_____________________ | | v> | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 | | v> |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | v> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . | | v> | . | | . | | . | | . | | v> | . | | . | |387420489) 9^..387420488)..^9<..< . | | v> |387420489) 9^..387420488)..^9<..< . | | levels| | . | | v> | levels | | . | | ..9^........^9 | | v> ..9^.........^9<...< bays | | v> section levels | | ___________________________________^_________ | | v> | |/ . | | v> | | . | | v> | | . | | v> | | ___________________________________^_________ | | v> | |/ 1) 9^9 / / 1) 9^9 | | v> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | v> | | . | | . | | v> | | . | | . | | v> | |387420489) 9^..387420488)..^9<..< . | | v> | | levels | | . | | v> ..9^........^9 | | v> section bays | | v> _____________________________________________________________ _____________________________________^_________ | | v> / . | | v> . >....>> . | | > _____________________________________________________________ _____________________________________^_________ | |> / / 387420488 bays | |> | _______________________^_____________________ | |> |/ 1) 9^9=387420489 / / 1) 9^9 | |> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | |> | . | | . | |> | . | | . | |> |387420489) 9^..387420488)..^9<..< . | |> | levels| | . | |> | ..9^........^9 | |> | bays | |> 387420488< ______________________________________^______ | |> section|/ . | |> levels | . / / 387420488 bays | |> | . | | _______________________^_____________________ | |> | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 | |> |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | |> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . | |> | . | | . | | . | | . | |> | . | | . | |387420489) 9^..387420488)..^9<..< . | |> |387420489) 9^..387420488)..^9<..< . | | levels| | . | |> | levels | | . | | ..9^........^9 | |> ..9^.........^9<...< bays | |> section levels | | ___________________________________^_________ | |> | |/ . | |> | | . | |> | | . | |> | | ___________________________________^_________ | |> | |/ 1) 9^9 / / 1) 9^9 | |> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | |> | | . | | . | |> | | . | | . | |> | |387420489) 9^..387420488)..^9<..< . | |> | | levels | | . | |> ..9^........^9 / /> bays of section bays > _____________________________________________________________ __________________________________________^__________________ _____________________________________________________________ ____________________________________________________ |> / 387420488 section bays |> _____________________________________________________________ __^____________________________________________ |> / |> / 387420488 bays | > | _______________________^_____________________ |> |/ 1) 9^9=387420489 / / 1) 9^9 / / 387420488 section bays |> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | _____________________________________________________________ __^____________________________________________ | > | . | | . | |/ | > | . | | . | | / 387420488 bays |> |387420489) 9^..387420488)..^9<..< . | | | _______________________^_____________________ |> | levels| | . | | |/ 1) 9^9=387420489 / / 1) 9^9 |> | ..9^........^9 | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | bays | | | . | | . |> /387420488< ______________________________________^______ | | | . | | . |> | section|/ . | | |387420489) 9^..387420488)..^9<..< . |> | levels | . / / 387420488 bays | | | levels| | . |> | | . | | _______________________^_____________________ | | | ..9^........^9 |> | | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 | | | bays |> | |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | |387420488< ______________________________________^______ |> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . | | section|/ . |> | | . | | . | | . | | . | | levels | . / / 387420488 bays |> | | . | | . | |387420489) 9^..387420488)..^9<..< . | | | . | | _______________________^_____________________ |> | |387420489) 9^..387420488)..^9<..< . | | levels| | . | | | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 |> | | levels | | . | | ..9^........^9 | | |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | ..9^.........^9<...< bays | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . |> | section levels | | ___________________________________^_________ | | | . | | . | | . | | . |> | | |/ . | | | . | | . | |387420489) 9^..387420488)..^9<..< . |> | | | . | | |387420489) 9^..387420488)..^9<..< . | | levels| | . |> | | | . | | | levels | | . | | ..9^........^9 |> | | | ___________________________________^_________ | | ..9^.........^9<...< bays |> | | |/ 1) 9^9 / / 1) 9^9 | | section levels | | ___________________________________^_________ |> | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | | |/ . |> 387420488< | | . | | . | | | | . |> levels of| | | . | | . | | | | . |> section | | |387420489) 9^..387420488)..^9<..< . | | | | ___________________________________^_________ |> levels | | | levels | | . | | | |/ 1) 9^9 / / 1) 9^9 |> | ..9^........^9 | | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | section bays | | | | . | | . |> | _____________________________________________________________ _____________________________________^_________ | | | | . | | . |> |/ . | | | |387420489) 9^..387420488)..^9<..< . |> | . | | | | levels | | . |> | . | | ..9^........^9 |> | _____________________________________________________________ _____________________________________^_________ | | section bays |> |/ / 387420488 bays | | _____________________________________________________________ _____________________________________^_________ |> | | _______________________^_____________________ | |/ . |> | |/ 1) 9^9=387420489 / / 1) 9^9 | | . |> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . |> | | . | | . | | _____________________________________________________________ _____________________________________^_________ |> | | . | | . | |/ / 387420488 bays |> | |387420489) 9^..387420488)..^9<..< . | | | _______________________^_____________________ |> | | levels| | . | | |/ 1) 9^9=387420489 / / 1) 9^9 |> | | ..9^........^9 | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | | bays | | | . | | . |> |387420488< ______________________________________^______ | | | . | | . |> | section|/ . | | |387420489) 9^..387420488)..^9<..< . |> levels | . / / 387420488 bays | | | levels| | . |> | . | | _______________________^_____________________ | | | ..9^........^9 |> | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 | | | bays |> |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | |387420488< ______________________________________^______ |> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . | | section|/ . |> | . | | . | | . | | . | | levels | . / / 387420488 bays |> | . | | . | |387420489) 9^..387420488)..^9<..< . | | | . | | _______________________^_____________________ |> |387420489) 9^..387420488)..^9<..< . | | levels| | . | | | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 |> | levels | | . | | ..9^........^9 | | |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> ..9^.........^9<...< bays | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . |> section levels | | ___________________________________^_________ | | | . | | . | | . | | . |> | |/ . | | | . | | . | |387420489) 9^..387420488)..^9<..< . |> | | . | | |387420489) 9^..387420488)..^9<..< . | | levels| | . |> | | . | | | levels | | . | | ..9^........^9 |> | | ___________________________________^_________ | | ..9^.........^9<...< bays |> | |/ 1) 9^9 / / 1) 9^9 | | section levels | | ___________________________________^_________ |> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | | |/ . |> | | . | | . | | | | . |> | | . | | . | | | | . |> | |387420489) 9^..387420488)..^9<..< . | | | | ___________________________________^_________ |> | | levels | | . | | | |/ 1) 9^9 / / 1) 9^9 |> ..9^........^9 | | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> levels of section bays<....< | | . | | . |> | | | | . | | . |> | | | |387420489) 9^..387420488)..^9<..< . | > | | | | levels | | . |> ..9^........^9 |> bays of bays > section bays |> _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ __________________________________________^_________ |> / . |> . |> . |> _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ __________________________________________^_________ |> / | 8> 387420488 section bays > levels> _____________________________________________________________ __^____________________________________________ |of bays> / |of sect.> / 387420488 bays |bays> | _______________________^_____________________ |> |/ 1) 9^9=387420489 / / 1) 9^9 / / 387420488 section bays |> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | _____________________________________________________________ __^____________________________________________ | > | . | | . | |/ | > | . | | . | | / 387420488 bays |> |387420489) 9^..387420488)..^9<..< . | | | _______________________^_____________________ |> | levels| | . | | |/ 1) 9^9=387420489 / / 1) 9^9 |> | ..9^........^9 | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | bays | | | . | | . |> /387420488< ______________________________________^______ | | | . | | . |> | section|/ . | | |387420489) 9^..387420488)..^9<..< . |> | levels | . / / 387420488 bays | | | levels| | . |> | | . | | _______________________^_____________________ | | | ..9^........^9 |> | | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 | | | bays |> | |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | |387420488< ______________________________________^______ |> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . | | section|/ . |> | | . | | . | | . | | . | | levels | . / / 387420488 bays |> | | . | | . | |387420489) 9^..387420488)..^9<..< . | | | . | | _______________________^_____________________ |> | |387420489) 9^..387420488)..^9<..< . | | levels| | . | | | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 |> | | levels | | . | | ..9^........^9 | | |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | ..9^.........^9<...< bays | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . |> | section levels | | ___________________________________^_________ | | | . | | . | | . | | . |> | | |/ . | | | . | | . | |387420489) 9^..387420488)..^9<..< . |> | | | . | | |387420489) 9^..387420488)..^9<..< . | | levels| | . |> | | | . | | | levels | | . | | ..9^........^9 |> | | | ___________________________________^_________ | | ..9^.........^9<...< bays |> | | |/ 1) 9^9 / / 1) 9^9 | | section levels | | ___________________________________^_________ |> | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | | |/ . |> 387420488< | | . | | . | | | | . |> levels of| | | . | | . | | | | . |> section | | |387420489) 9^..387420488)..^9<..< . | | | | ___________________________________^_________ |> levels | | | levels | | . | | | |/ 1) 9^9 / / 1) 9^9 |> | ..9^........^9 | | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | section bays | | | | . | | . |> | _____________________________________________________________ _____________________________________^_________ | | | | . | | . |> |/ . | | | |387420489) 9^..387420488)..^9<..< . |> | . | | | | levels | | . |> | . | | ..9^........^9 |> | _____________________________________________________________ _____________________________________^_________ | | section bays |> |/ / 387420488 bays | | _____________________________________________________________ _____________________________________^_________ |> | | _______________________^_____________________ | |/ . |> | |/ 1) 9^9=387420489 / / 1) 9^9 | | . |> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . |> | | . | | . | | _____________________________________________________________ _____________________________________^_________ |> | | . | | . | |/ / 387420488 bays |> | |387420489) 9^..387420488)..^9<..< . | | | _______________________^_____________________ |> | | levels| | . | | |/ 1) 9^9=387420489 / / 1) 9^9 |> | | ..9^........^9 | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> | | bays | | | . | | . |> |387420488< ______________________________________^______ | | | . | | . |> | section|/ . | | |387420489) 9^..387420488)..^9<..< . |> levels | . / / 387420488 bays | | | levels| | . |> | . | | _______________________^_____________________ | | | ..9^........^9 |> | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 | | | bays |> |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | |387420488< ______________________________________^______ |> | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . | | section|/ . |> | . | | . | | . | | . | | levels | . / / 387420488 bays |> | . | | . | |387420489) 9^..387420488)..^9<..< . | | | . | | _______________________^_____________________ |> |387420489) 9^..387420488)..^9<..< . | | levels| | . | | | ______________________________________^______ | |/ 1) 9^9 / / 1) 9^9 |> | levels | | . | | ..9^........^9 | | |/ 1) 9^9 / / 1) 9^9 | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> ..9^.........^9<...< bays | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | . | | . |> section levels | | ___________________________________^_________ | | | . | | . | | . | | . |> | |/ . | | | . | | . | |387420489) 9^..387420488)..^9<..< . |> | | . | | |387420489) 9^..387420488)..^9<..< . | | levels| | . |> | | . | | | levels | | . | | ..9^........^9 |> | | ___________________________________^_________ | | ..9^.........^9<...< bays |> | |/ 1) 9^9 / / 1) 9^9 | | section levels | | ___________________________________^_________ |> | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 | | | |/ . |> | | . | | . | | | | . |> | | . | | . | | | | . |> | |387420489) 9^..387420488)..^9<..< . | | | | ___________________________________^_________ |> | | levels | | . | | | |/ 1) 9^9 / / 1) 9^9 |> ..9^........^9 | | | | 2) 9^..1)..^9 | | 2) 9^..1)..^9 |> levels of section bays<....< | | . | | . |> | | | | . | | . |> | | | |387420489) 9^..387420488)..^9<..< . |> | | | | levels | | . |> approve@localhost) by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id h9GFkWI12344; =Malcolm generally covered within a position of both the second and third raised to indicate a v and the rst touching the fourth at a midway position whilst the fth is aligned to 180 degrees to the second and third yes a st full of digits as descibed you have placed a victory sign what is then held high in front of the world to see Peter, Bloody inventor of ings >
>Are there any mathematicians
out there who are concerned about the>implications of the
concept of Constructivism for maths? I must admit that>what
little I know about it gives cause for a modicum of alarm. I
would>very much like to discuss this matter with someone who
is familiar with the>limitations of oating point numbers,
particularly the theory of>signicant digits. >>
Exposing the war for prot game is like turning>on the tap of a high pressure bull faucet.> Tom Potter http://tompotter.us>> The fact of the matter is that the Germans are perhaps the> most moral, intelligent and productive folks on the planet,> and they have been demonized because they had to turn> to a political [Nazi] party pledged to control the Bolshevik> instigators, terrorists, murderers and assassins, who were> creating death and destruction all over the world in the 1900s,> committed to going after the Bolsheviks terrorists. -- Tom>Tom, in case you are leaving or have left for Germany,the land of your dreams with its most intelligent peoplelet me offer you some info that might save your ass fromembarrassment and perhaps even more severe consequences.your age (except perhaps todays youngsters below 25) donot have any tolerance for what you are preaching.== During my years in DE, there was the case where aguy stopped at the autobahn and helped two woman to changetheir at tire. They offered him 20 bucks for his service, buthe brushed it away with the remark: ich bin doch kein Judeand drove off. 3 weeks latter he got hauled into court for havingmade disparaging remarks against Jews.== Dont make any of your propaganda neither in neighboringSwitzerland. They have their Artikel 261. Due to this law a doctorsits in jail because he railed against the Jewish method ofSchaechten = butchering cattle, kosher style.== Again from Germany here is a story off the wires from today:http://www.reuters.com/newsArticle.jhtml?type= oddlyEnoughNews&storyID=3621259BERLIN (Reuters) - A German man who taught his dog Adolf to giveGermanys anti-Nazi laws for a series of incidents in recent years, aBerlin court said on Wednesday. Germany has strict laws banning themustache and military tunic, said he didnt understand what thefuss was about. The trial is set for Thursday. Thein is accused ofshouting the Nazi battlecry Sieg Heil in front of Berlin police and ofcity in separate incidents in 2002. (Additional reporting by Erik Kirschbaum)All your stories you were telling at our NGs cyber party here, aboutthe Germans greatness, aint gonna be an effective defense inDeutschland...........ahahahahah..........ahahahaEnjoy the beer while youre over there. Not WWII politics.ahahahaha..........ahahahahahanson Exposing the war for prot game is like turning>on the tap of a high pressure bull faucet.> Tom Potter http://tompotter.us>> The fact of the matter is that the Germans are perhaps the> most moral, intelligent and productive folks on the planet,> and they have been demonized because they had to turn> to a political [Nazi] party pledged to control the Bolshevik> instigators, terrorists, murderers and assassins, who were> creating death and destruction all over the world in the 1900s,> committed to going after the Bolsheviks terrorists. -- Tom>> Tom, in case you are leaving or have left for Germany,> the land of your dreams with its most intelligent people> let me offer you some info that might save your ass from> embarrassment and perhaps even more severe consequences.> your age (except perhaps todays youngsters below 25) do> not have any tolerance for what you are preaching.== During my years in DE, there was the case where a> guy stopped at the autobahn and helped two woman to change> their at tire. They offered him 20 bucks for his service, but> he brushed it away with the remark: ich bin doch kein Jude> and drove off. 3 weeks latter he got hauled into court for having> made disparaging remarks against Jews.== Dont make any of your propaganda neither in neighboring> Switzerland. They have their Artikel 261. Due to this law a doctor> sits in jail because he railed against the Jewish method of> Schaechten = butchering cattle, kosher style.== Again from Germany here is a story off the wires from today:> http://www.reuters.com/newsArticle.jhtml?type=oddlyEnoughNews &storyID=3621259> BERLIN (Reuters) - A German man who taught his dog Adolf to give> Germanys anti-Nazi laws for a series of incidents in recent years, a> Berlin court said on Wednesday. Germany has strict laws banning the> mustache and military tunic, said he didnt understand what the> fuss was about. The trial is set for Thursday. Thein is accused of> shouting the Nazi battlecry Sieg Heil in front of Berlin police and of> city in separate incidents in 2002. (Additional reporting by Erik Kirschbaum)All your stories you were telling at our NGs cyber party here, about> the Germans greatness, aint gonna be an effective defense in> Deutschland...........ahahahahah..........ahahaha> Enjoy the beer while youre over there. Not WWII politics.> ahahahaha..........ahahahahahansonhanson makes a good point about Defeated nations having the dogma of the victors enforced on them, regardless of the truth or value of the dogma.He also makes a good point about the fact that harsh laws have been forced on the Germans, inhibiting their free speech.Of course, the same thing happened when the Bolsheviks co-opted the government of Russia, from the native Russians. The rst law they passed made criticism of Jews punishable by ring squad.Intelligent, rational, moral folks, who believe in free speech, justice, equity, and the brotherhood of man, and who are concerned about making the world a better place to live in for ALL people should learn from these examples.If folks are inhibited by brainwashing, and harsh laws, from criticizing certain classes of people, it gives carte blanche to that class to do as they please.Can you imagine what kind of world it would be if folks were jailed, or even executed, for criticizing Microsoft?????--Tom Potter > Modern socialism is a balance of public and private>> enterprise with an adiquate social safety net.>>That means stealing from one and giving to other via taxes.>Taxation is Theft>> Stupidity alert!>Parki-pooh, you do not have to precede any of your intellectually>>empty posts with any alert!. Everyone knows that you are stupid.>>The poster is obviously a taxpayer, hence a contributor to your>>salary, since you are on the public payroll, as a college professor.>> I see somebody is too dumb to know the difference between public>> universities and private ones.>>ahahahah.......ahahahahha.......>lie, twist it any way you want, Parki-pooh, the lparker@emory.edu :>You are feeding off the public trough, which the OP, me and millions >of other taxpayers ll up for you.....thats why your hangout has... >--- .....to comply with new **Federal** regulations, Emory University>has developed a set of **Cost Accounting** Standard Policies. >--- EMORY UNIVERSITY RECEIVES $225,000 GRANTHaliburton received a multi-billion dollar contract from the government. Does that make all its employees public employees?>FROM U.S. DEPARTMENT OF ENERGY ......etc., etc....>Do I need to post more such tid bits and their urls, Parki-pooh?>ahahahahha........ahahahansonPerhaps you need to learn how to read. > Modern socialism is a balance of public and private>> enterprise with an adiquate social safety net.>>That means stealing from one and giving to other via taxes.>Taxation is Theft>> Stupidity alert!>Parki-pooh, you do not have to precede any of your intellectually>>empty posts with any alert!. Everyone knows that you are stupid.>>The poster is obviously a taxpayer, hence a contributor to your>>salary, since you are on the public payroll, as a college professor.>> I see somebody is too dumb to know the difference between public>> universities and private ones.>ahahahah.......ahahahahha.......>lie, twist it any way you want, Parki-pooh, the lparker@emory.edu :>..... where as an associate professor for the last 25 years, ..... >you are feeding off the public trough, which the OP, me and millions >of other taxpayers ll up for you.....thats why your hangout has... >--- .....to comply with new **Federal** regulations, Emory University>has developed a set of **Cost Accounting** Standard Policies. >--- EMORY UNIVERSITY RECEIVES $225,000 GRANT>FROM U.S. DEPARTMENT OF ENERGY ......etc., etc....>Do I need to post more such tid bits and their urls, Parki-pooh?>ahahahahha........ahahahanson>> Haliburton received a multi-billion dollar contract from the > government. Does that make all its employees public employees?> Perhaps you need to learn how to read.> Parki-pooh, see, you are twisting and spinning again, but it doesntdo you no good. We are not talking about them, Parki. We aretalking about you cussing at taxpayers who fund your salary.If you are denying that, its probably due to the fact that you do know this and that you are not delivering enough for paymentreceived, and feel guilty..........your guilt shows Parki, it shows........ahahahahaha.......ahahahahanson Modern socialism is a balance of public and private> enterprise with an adiquate social safety net.>>That means stealing from one and giving to other via taxes.>>Taxation is Theft>> Stupidity alert!>Parki-pooh, you do not have to precede any of your intellectually>empty posts with any alert!. Everyone knows that you are stupid.>The poster is obviously a taxpayer, hence a contributor to your>salary, since you are on the public payroll, as a college professor.>> I see somebody is too dumb to know the difference between public> universities and private ones.>ahahahah.......ahahahahha.......>>lie, twist it any way you want, Parki-pooh, the lparker@emory.edu :>>..... where as an associate professor for the last 25 years, ..... >>you are feeding off the public trough, which the OP, me and millions >>of other taxpayers ll up for you.....thats why your hangout has... >>--- .....to comply with new **Federal** regulations, Emory University>>has developed a set of **Cost Accounting** Standard Policies. >>--- EMORY UNIVERSITY RECEIVES $225,000 GRANT>>FROM U.S. DEPARTMENT OF ENERGY ......etc., etc....>>Do I need to post more such tid bits and their urls, Parki-pooh?>>ahahahahha........ahahahanson>> Haliburton received a multi-billion dollar contract from the >> government. Does that make all its employees public employees?>> Perhaps you need to learn how to read.>Parki-pooh, see, you are twisting and spinning again, but it doesnt>do you no good. We are not talking about them, Parki. We are>talking about you cussing at taxpayers who fund your salary.Well, that obviously doesnt include you.>If you are denying that, its probably due to the fact that you do >know this and that you are not delivering enough for payment>received, and feel guilty..........your guilt shows Parki, it shows........>ahahahahaha.......ahahahahanson Modern socialism is a balance of public and private> enterprise with an adiquate social safety net.>>That means stealing from one and giving to other via taxes.>>Taxation is Theft>> Stupidity alert!>Parki-pooh, you do not have to precede any of your intellectually>empty posts with any alert!. Everyone knows that you are stupid.>The poster is obviously a taxpayer, hence a contributor to your>salary, since you are on the public payroll, as a college professor.>> I see somebody is too dumb to know the difference between public> universities and private ones.>ahahahah.......ahahahahha.......>>lie, twist it any way you want, Parki-pooh, the lparker@emory.edu :>>..... where as an associate professor for the last 25 years, ..... >>you are feeding off the public trough, which the OP, me and millions >>of other taxpayers ll up for you.....thats why your hangout has... >>--- .....to comply with new **Federal** regulations, Emory University>>has developed a set of **Cost Accounting** Standard Policies. >>--- EMORY UNIVERSITY RECEIVES $225,000 GRANT>>FROM U.S. DEPARTMENT OF ENERGY ......etc., etc....>>Do I need to post more such tid bits and their urls, Parki-pooh?>>ahahahahha........ahahahanson>> Haliburton received a multi-billion dollar contract from the >> government. Does that make all its employees public employees?>> Perhaps you need to learn how to read.>>Parki-pooh, see, you are twisting and spinning again, but it doesnt>do you no good. We are not talking about them, Parki. We are>talking about you cussing at taxpayers who fund your salary.Well, that obviously doesnt include you.> AHAHAHHAHA........ahahahaha........taxpayers DO fund your salary. It wasnt so hard, wasnt it, Parki?Take care dude, laughs,hahahahaha........ahahahanson>If you are denying that, its probably due to the fact that you do >know this and that you are not delivering enough for payment>received, and feel guilty..........your guilt shows Parki, it shows........>ahahahahaha.......ahahahahanson =[snip...]> ahahahah.......ahahahahha.......> lie, twist it any way you want, Parki-pooh, the lparker@emory.edu :> You are feeding off the public trough, which the OP, me and millions > of other taxpayers ll up for you.....thats why your hangout has... > --- .....to comply with new **Federal** regulations, Emory University> has developed a set of **Cost Accounting** Standard Policies. > --- EMORY UNIVERSITY RECEIVES $225,000 GRANT> FROM U.S. DEPARTMENT OF ENERGY ......etc., etc....> Do I need to post more such tid bits and their urls, Parki-pooh?> ahahahahha........ahahahansonPS: Or are you so lthy rich, that you can afford to sit there, doing> tale, [snip...]Hanson. Hanson. For Gods sake, man....Hanson...reach around behind your skull;feel with your ngertips. Find the smallnode, the bump? Thats the RESET button,Hanson. PUSH IT, Hanson, PUSH IT. Mark (I probably am in over my head, but.... :-) [snip...]> ahahahah.......ahahahahha.......> lie, twist it any way you want, Parki-pooh, the lparker@emory.edu :> You are feeding off the public trough, which the OP, me and millions> of other taxpayers ll up for you.....thats why your hangout has...> --- .....to comply with new **Federal** regulations, Emory University> has developed a set of **Cost Accounting** Standard Policies.> --- EMORY UNIVERSITY RECEIVES $225,000 GRANT> FROM U.S. DEPARTMENT OF ENERGY ......etc., etc....> Do I need to post more such tid bits and their urls, Parki-pooh?> ahahahahha........ahahahanson>> PS: Or are you so lthy rich, that you can afford to sit there, doing> tale, [snip...]>> Hanson. Hanson. For Gods sake, man....> Hanson...reach around behind your skull;> feel with your ngertips. Find the small> node, the bump? Thats the RESET button,> Hanson. PUSH IT, Hanson, PUSH IT.>Awe, .....your are plagiarizing out of Ripleys. Shame on you. Besides, Parki-pooh already did it . He broke it. Now what ?awawawawa......hahahanson>> Mark (I probably am in over my head, but.... :-) [snip...]> ahahahah.......ahahahahha.......> lie, twist it any way you want, Parki-pooh, the lparker@emory.edu :> You are feeding off the public trough, which the OP, me and millions> of other taxpayers ll up for you.....thats why your hangout has...> --- .....to comply with new **Federal** regulations, Emory University> has developed a set of **Cost Accounting** Standard Policies.> --- EMORY UNIVERSITY RECEIVES $225,000 GRANT> FROM U.S. DEPARTMENT OF ENERGY ......etc., etc....> Do I need to post more such tid bits and their urls, Parki-pooh?> ahahahahha........ahahahanson>> PS: Or are you so lthy rich, that you can afford to sit there, doing> tale, [snip...]>> Hanson. Hanson. For Gods sake, man....> Hanson...reach around behind your skull;> feel with your ngertips. Find the small> node, the bump? Thats the RESET button,> Hanson. PUSH IT, Hanson, PUSH IT.>> Awe, .....your are plagiarizing out of Ripleys. > Shame on you. Besides, Parki-pooh already did it . > He broke it. Now what ?> awawawawa......hahahansonI thought, and still do think, that theidea was an original.So burst my bubble, already -- Whos/whatsRipleys (Believe It or Die?) and what didParki-pooh already do thats related to theRESET idea?> Mark (I probably am in over my head, but.... :-) Mark (I have not followed this thread, nor intend to but for this small intrusion :-) > -->> Intelligence is a constant. Population grows.>>Irrwahn Grausewitz is living proof of his sig.Its you who is a living prove of my sig, as it turned out you are not > even able to read my post, despite understand its contents. Now go > trolling somewhere else. Fup2 set accordingly.Ah yes, I almost forgot: *PLONK*Note That Irrwahn Grausewitzs sig reveals a lot about him.He apparently thinks [sic] that he is of superior intelligence, and that this makes him superior to the folks who he thinks [sic] are of lesser intelligence, even though many, if not most of the things that make life worth while are produced by the very folks that Irrwahn Grausewitz thinks [sic] that he is superior to.that he shouldnt play newgroup policeman, or if he has an irresistable compulsion to play policemen, that he should go after the real culprits, rather than bushwhack posters who respond to posts.--Tom Potter Im trying to work out how to calculate the> distance from an N-dimensional point to an> N-dimensional hull.Ive looked around for an answer, but most> are specic to a certain dimension.I need this for a machine learning method Im trying> to implement, which replaces hyperrectangles in> Neareast Neighbour with Generalisation with convex> hulls instead. Im currently using qhull for creating> convex hulls.Any help would be much appreciated, as Ive> spent the last few days trying to come up with> a method. I have some ideas, but Im not sure about> them and would take alot of time to implement.> SO I thought Id check rst ;)This is a convex program:find the coordinates of a linear function that is nonnegative on each of the points of the hull and negative on the query point (a collection of linear inequality constraints) maximizing the distance from the query point to the hyperplane of zeros of the linear function (convex quadratic objective function). So you should be able to handle this with any convex programming package, but unless N is very small there is not going to be much else to do.If youre looking at this in the context of machine learning, you should also look at Support Vector Machines, which typically involve similar convex programs for the distance between two hulls.-- David Eppstein http://www.ics.uci.edu/~eppstein/Univ. of California, Irvine, School of Information & Computer Science =Apparently, you do ->NOT<- want to take me up on the offer. Readerswho have seen you complain for years about my blocking you and howif I wasnt things would go swimmingly, might wonder what exactly areyou afraid of, when I offer to simply step out of the way if youlljust say the word.>>Theres actually a rather small group of posters, including this>>poster, a poster that goes by Nora Baron, Arturo Magidin, and Dik>>Winter, who make rather remarkably dumb mistakes throughout their>>posts, yet somehow theyve managed to convince much of the readership>>that they are competent at mathematics. Strange, that you have never been able to substantiate any of these>> rather remarkably dumb mistakes.>>For months now this poster has been working to cast doubt on a rather>simple argument, where Ifind terms independent of a variable I call>m, by challenging my use of m=0 to clear it out.This is, as you like to say, a fascinating lie.While I have pointed out that your use of independent term isnonstandard for functions which are not polynomials, nobody hasobjected to you dening them to be the value when m=0. So yourclaim that I have been working to cast doubt [...] by challenging myuse of m=0 to clear it out is a lie.In fact, everyone agrees that what you do with m=0 is correct. Whatnobody seems to agree with you about is the conclusions you derivefrom your analysis of the m=0 case. Namely, you claim that becausewhen m=0, you have g_1(0) and g_2(0) multiples of f and g_3(0) coprimeto f, then it follows that g_1(m) and g_2(m) are always multiples of ffor every value of m, and g_3(m) is always coprime to f for everymultiple of m.You lie when you claim that people are challenging the antecedent ofthe implication. They are challenging the implication. Challenging theimplication means saying that the antecedent is true, BUT theconsequent is not.The challenge is not to what happens when m=0; the challenge is toyour claim that what happens when m=0 MUST ALSO HAPPEN WHEN m<>0.>However, its rather a basic thing that if terms are independent of a>variable, then it doesnt matter WHAT that variables value is, which>is why theyre independent.This is a misrepresentation of the issue, born out of your lack ofunderstanding of the criticisms leveled at your argument.>Thats a fascinatingly dumb thing to question for MONTHS and in fact>shows that either Arturo Magidin is remarkably dumb, or is, as I>believe, a well practiced liar who knows how to appear convincing.False dichotomy. Other possibilities:(a) You have misunderstood what I have said, whether deliberately or through incompetence.(b) You are remarkably dumb and have made mistakes you are unable to recognize.(c) Both (a) and (b).(d) Other. [.snip.] such a reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can criticize. A great many people are staggered to this extent, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de Morgan Magidinmagidin@math.berkeley.edu =Apparently, you do ->NOT<- want to take me up on the offer. Readers> who have seen you complain for years about my blocking you and how> if I wasnt things would go swimmingly, might wonder what exactly are> you afraid of, when I offer to simply step out of the way if youll> just say the word.>>Theres actually a rather small group of posters, including this>>poster, a poster that goes by Nora Baron, Arturo Magidin, and Dik>>Winter, who make rather remarkably dumb mistakes throughout their>>posts, yet somehow theyve managed to convince much of the readership>>that they are competent at mathematics.> Strange, that you have never been able to substantiate any of these>> rather remarkably dumb mistakes.>>For months now this poster has been working to cast doubt on a rather>simple argument, where Ifind terms independent of a variable I call>m, by challenging my use of m=0 to clear it out.This is, as you like to say, a fascinating lie.Readers who want to know the truth need only read further down, to seejust how Arturo Magidin operates.Read below...> While I have pointed out that your use of independent term is> nonstandard for functions which are not polynomials, nobody has> objected to you dening them to be the value when m=0. So your> claim that I have been working to cast doubt [...] by challenging my> use of m=0 to clear it out is a lie.In fact, everyone agrees that what you do with m=0 is correct. What> nobody seems to agree with you about is the conclusions you derive> from your analysis of the m=0 case. Namely, you claim that because> when m=0, you have g_1(0) and g_2(0) multiples of f and g_3(0) coprime> to f, then it follows that g_1(m) and g_2(m) are always multiples of f> for every value of m, and g_3(m) is always coprime to f for every> multiple of m.Here readers can see the poster focusing on m=0, but obviously ifterms are independent of the value of m, then ms value just doesntmatter. > You lie when you claim that people are challenging the antecedent of> the implication. They are challenging the implication. Challenging the> implication means saying that the antecedent is true, BUT the> consequent is not.The challenge is not to what happens when m=0; the challenge is to> your claim that what happens when m=0 MUST ALSO HAPPEN WHEN m<>0.>However, its rather a basic thing that if terms are independent of a>variable, then it doesnt matter WHAT that variables value is, which>is why theyre independent.This is a misrepresentation of the issue, born out of your lack of> understanding of the criticisms leveled at your argument.>Thats a fascinatingly dumb thing to question for MONTHS and in fact>shows that either Arturo Magidin is remarkably dumb, or is, as I>believe, a well practiced liar who knows how to appear convincing.False dichotomy. Other possibilities:(a) You have misunderstood what I have said, whether deliberately or> through incompetence.(b) You are remarkably dumb and have made mistakes you are unable to> recognize.(c) Both (a) and (b).(d) Other. [.snip.]All thats important is that values independent of m are independentof m.Its a simple technique tofind values independent of m by settingm=0.James Harris >> Apparently, you do ->NOT<- want to take me up on the offer. Readers>> who have seen you complain for years about my blocking you and how>> if I wasnt things would go swimmingly, might wonder what exactly are>> you afraid of, when I offer to simply step out of the way if youll>> just say the word.>>Theres actually a rather small group of posters, including this>poster, a poster that goes by Nora Baron, Arturo Magidin, and Dik>Winter, who make rather remarkably dumb mistakes throughout their>posts, yet somehow theyve managed to convince much of the readership>that they are competent at mathematics.> Strange, that you have never been able to substantiate any of these> rather remarkably dumb mistakes.>>For months now this poster has been working to cast doubt on a rather>>simple argument, where Ifind terms independent of a variable I call>>m, by challenging my use of m=0 to clear it out. This is, as you like to say, a fascinating lie.> Readers who want to know the truth need only read further down, to see> just how Arturo Magidin operates.We can see very clearly how *you* operate. Youre afraid to acceptArturos offer to stop replying to you, because you know that theattention that he (and Nora and Dik and others) give you with theirreplies is the only thing that lends any semblance of credibility toyou at all.-- Wayne Brown (HPCC #1104) | When your tails in a crack, you improvisefwbrown@bellsouth.net | if youre good enough. Otherwise you give | your pelt to the trapper.e^(i*pi) = -1 -- Euler | -- John Myers Myers, Silverlock =no, dont say it ... its too obvious ... youll ruin your mind! oh, heck; the medium is the message. yeeha. > attention that he (and Nora and Dik and others) give you with their> replies is the only thing that lends any semblance of credibility to--les ducs dEnron! :> What is the false implication?> ::> > : The false implication is that b is a non-unit factor of 2 like> : sqrt(2), or 2^{1/3}, when in fact, appropriately, its a factor of 1.> : Unfortunately the poster deleted out pertinent information, so Ill> : make the effort to put it back in so that it makes sense to readers> : without forcing them to go back to previous posts.> : I gave the example of xy = 2, where x and y are algebraic integers,> : where x=2a and y=b, so b is an algebraic integer, but a is not, but> : it is a member of what I call the object ring.> : The object ring is a commutative ring that includes all numbers such> : that -1 and 1 are the only members that are both a unit and an> : integer, where no non-unit member is a factor of any two integers that> : are coprime.> : Notice that denition for the object ring excludes possibilities like> : a=1/2 as then 2 would be a unit since 2(1/2) = 1.> : So, in fact, in the object ring, ab=1 and b IS a unit, but because a> : is inappropriately excluded from the ring of algebraic integers by the> : denition of algebraic integers as roots of monic polynomials with> : integer coefcients, you have the false implication that b is some> : other type factor of 2.> : Now then, say you follow algebra, and then youfind that you have 2 as> : a factor of x, well youve been pushed out of the ring of algebraic> : integers where x does NOT have 2 as a factor, even though x=2a.> :> :> : And you can see several problems that popped up by that exclusion as b> :> :> : is not a unit in the ring of algebraic integers, when it should be,> :> :> : and x does NOT have 2 as a factor in the ring, though x=2a.> :> ::> :> So, what is the problem? I havent seen anything that looks like > :> :> a contradiction, only an assertion that something is not a unit> :> :> which should be according to some unstated principle. Whats the> :> :> principle?> :> : Given that xy=2, with x=2a, y=b, with b an algebraic integer, x an> :> : algebraic integer, while a is not, it *should* be that y does not> :> : share non-unit factors with 2, since x *should* have 2 as a factor,> :> : but in the ring of algebraic integers, because the denition> :> : arbitrarily excludes a, neither of those is the case.> ::> What is behind the shoulds, i.e. what are the bad consequences of > :> excluding a? Before you were talking about being able to prove two > :> contradictory results.> ::> Mike> : The problem occurs because algebra does NOT recognize the arbitrary> : denition, so using algebra you canfind yourself in situations where> : you prove that x has 2 as a factor, but then again, because of this> : arbitrary denition, it does not, in the ring of algebraic integers.> : Since the assumption is that algebraic integers is an appropriate> : ring, it appears that youve proven two contradictory things:What do you mean by an appropriate ring?One where you cant appear to prove contradictory things. > : 1. x has 2 as a factor> : 2. x does NOT have 2 as a factorBut arent 1. and 2. actually:1. x has 2 as a factor in the object ringIll remind of the example of 2 and 6 in the ring of evens to helpreaders with context, as there 2 is not a factor of 6 because 3 isnteven.Now then, with my example, you have x=2a, where x is an algebraicinteger, but as a is not, it doesnt have 2 as a factor, in the ringof algebraic integers, which falsely implies, given that xy=2, where yis an algebraic integer that x and y have non-unit factors of 2 in thesame sense as like if you have sqrt(2) as a factor for both.But, in fact, *neither* has what you might call non-trivial factors of2 in the ring of algebraic integers, which I have to say as triviallythey have themselves as factors.That is, given that xy=2, x is trivially a factor of 2, in the ring ofalgebraic integers, as is y, when in fact x has a factor that IS 2, anon-trivial factor, in an appropriate ring, that is, one which doesnot allow contradictions.Its worth noting that proving that x doesnt have a factor of 2, inthe ring of algebraic integers, requires going to the eld ofalgebraic numbers, which is itself, of course, not awed.> 2. x does NOT have 2 as a factor in the algebraic integersAnd proving that requires going to the eld of algebraic numbers,which hasnt really been discussed at this point.So then *in the ring of algebraic integer* you can appear to prove*both* things, and only gure out that youve been pushed out of thering of algebraic integers, by going to the eld of algebraicnumbers.> These dont seem contradictory. MikeI keep talking about using mathematical logic as you can NOT just relyon your intuition.If you use mathematical logic then I can simply take you through eachstep of the proof, and then once you see what has to bemathematically, then you can begin to tailor your intuition to thereality.Months back--over a year ago--I even talked about quantum mechanics intrying to give an analogy, as an example of an advance in the eldthat forced its adherenents--there physicists--to rely less on theirintuition.But as a ccontrary group, mathematicians may simply be refusing to dowhat physicists had to do--rely less on intuition.What Ifind troubling is that even when repeatedly directed to rely onmathematical logic, mathematicians seem almost childishly unwilling todepend on what should be the very basis for their discipline.James Harris Im not following. You let x = 2a where x is an algebraic integer> and a is not. So x does not have a factor of 2 in the algebraic> integers. What is the contradictory proof that x *does* have a factor > of 2 in the algebraic integers?JSH does not answer questions.Gib =it does, if you permit a change of tense of shall;that is to say,its a conjecture that remains to be proven ... surely,I shall ... at least, I certainly could! Who you callin Inscrute, mister? > The fundamental problem is that should is not a word with a generally > accepted meaning in mathematics. JSH follows his own inscrutable rules, --Dec.2000 WAND Chairman Paul ONeill, reelected to Board. Newsish?http://www.rand.org/publications/randreview/issues/rr .12.00/http://members.tripod.com/~american_almanac =( also posted to sci.research.careers,comp.programming,sci.physics, sci.physics.computational.uid-dynamics,sci.math.num-analysis )I was wondering if anyone could give me feedback on this topic. I am34, have a scientic background, with Bachelors Degrees in Physicsand Math, graduate work in Physics and Optics culminating with an MSin Optics. I have worked as an engineer, and then as a programmer forthe last 5 years. However, it has been comercial programming (usingMicrosoft technologies such as Vsual C++, ASP, etc) and while I amthankful to have a job in the current economic climate, I am alsounhappy with the kind of work I am doing. I would like to do some sortof scientic programming, but I have not had much success applying tosuch jobs. They either require an existing security clearance or askfor tons of prior scientic programming experience.So my questions are:1) What do you think my chances are of getting such a scienticprogramming job? Would you expect a big difference when the economyimproves, hopefully in a few years?2) Any suggestions of specic places where I can apply for arelatively entry level scientic programming position?2) Are scientic programming jobs more secure than your typicalcommercial position? I have heard that being over 40 and a commercialprogrammer is a risky place to be, because of age discrimination andgeneral outsourcing. Are there many scientic programmers who so thattill they retire?If I cant nd such a job, I am considering getting an MBA, but Ireally think I would not enjoy that type of work nearly as much.-Sam Banerjee ( also posted to sci.research.careers,comp.programming,sci.physics, sci.physics.computational.uid-dynamics,sci.math.num-analysis > )> I was wondering if anyone could give me feedback on this topic. I am> 34, have a scientic background, with Bachelors Degrees in Physics> and Math, graduate work in Physics and Optics culminating with an MS> in Optics. I have worked as an engineer, and then as a programmer for> the last 5 years. However, it has been comercial programming (using> Microsoft technologies such as Vsual C++, ASP, etc) and while I am> thankful to have a job in the current economic climate, I am also> unhappy with the kind of work I am doing. I would like to do some sort> of scientic programming, but I have not had much success applying to> such jobs. They either require an existing security clearance or ask> for tons of prior scientic programming experience.>> So my questions are:>> 1) What do you think my chances are of getting such a scientic> programming job? Would you expect a big difference when the economy> improves, hopefully in a few years?>> 2) Any suggestions of specic places where I can apply for a> relatively entry level scientic programming position?>> 2) Are scientic programming jobs more secure than your typical> commercial position? I have heard that being over 40 and a commercial> programmer is a risky place to be, because of age discrimination and> general outsourcing. Are there many scientic programmers who so that> till they retire?>> If I cantfind such a job, I am considering getting an MBA, but I> really think I would not enjoy that type of work nearly as much.> -Sam BanerjeeYou didnt mention where you have tried tofind work, but one of the major employers of scientic programmers are companies involvedin test equipment and medical equipment. There are positions at all levels in such companies, and you mightfind a niche in one ofthem.--There are two things you must never attempt to prove: the unproveable -- and the obvious.--Democracy: The triumph of popularity over principle.--http://www.crbond.com ( also posted to sci.research.careers,comp.programming,sci.physics, sci.physics.computational.uid-dynamics,sci.math.num-analysis > )> I was wondering if anyone could give me feedback on this topic. I am> 34, have a scientic background, with Bachelors Degrees in Physics> and Math, graduate work in Physics and Optics culminating with an MS> in Optics. I have worked as an engineer, and then as a programmer for> the last 5 years. However, it has been comercial programming (using> Microsoft technologies such as Vsual C++, ASP, etc) and while I am> thankful to have a job in the current economic climate, I am also> unhappy with the kind of work I am doing. I would like to do some sort> of scientic programming, but I have not had much success applying to> such jobs. They either require an existing security clearance or ask> for tons of prior scientic programming experience.So my questions are:1) What do you think my chances are of getting such a scientic> programming job? Would you expect a big difference when the economy> improves, hopefully in a few years?2) Any suggestions of specic places where I can apply for a> relatively entry level scientic programming position?2) Are scientic programming jobs more secure than your typical> commercial position? I have heard that being over 40 and a commercial> programmer is a risky place to be, because of age discrimination and> general outsourcing. Are there many scientic programmers who so that> till they retire?If I cantfind such a job, I am considering getting an MBA, but I> really think I would not enjoy that type of work nearly as much.My guess, FWIW, is that people usually get into scientic programming by being involved with a research project in a university. Maybe your best bet would be to seek work in the eld of optics, where you have already established your credentials.Gib >could some expert recommend a Liapunov function that might help>control this plant represented by a nonlinear differential equation:>>y(t) = x(t) * ( 1 - F(s) * (|x(t)|^2) )>>here F(s) = K/(1+sb), represents a 1st order low pass lter>(convolution with Kexp(-bt)) with time constant 1/b, and K is a>small positive number, so y is nearly x but not exactly; both b and>K are unknown although I have a good idea of their value within a>factor of 2.>>( By F(s) * (|x|^2) is meant the square of x(t), x(t)^2, is low pass>ltered by F(s).)>>I need a control law x = C[u, y],for positive u>0, such that the>tracking error |y-u| is small.>I think what you said was dx/dt = x - F x^3 Is this what you mean? If so, you get dz/dt = (-z + F )/2with z = 1/x^2This equation should be much easier to work with. Evaluate the innite sum 1/1 + 2/2 + 3/4 + 4/8 + ... .?????>> Okay, I evaluated it... now what should I do?>> adam>>with a preposition? do is just add up all those numbers.Ill get you started:1 + 2 = 33 + 3/4 = 15/415/4 + 4/8 = 17/4etcadam =The is a physics problem, but Im hoping someone here might be able to help.Im trying tofind the tangential velocity of a body (mass: .127kg), yingaround in a circle from a string of unknown length. The radius is the circleis .43m, and using an astrolabe, I found the angle to be 58 degrees.With v = wr, my problem right now is trying to nd the angular velocity (w)to mutliply by the radius. I converted the 58 degrees to radian to get 1.012rad, but Im not sure what else to do. The time for the body to complete afull circle is not given, and were supposed to be able to get this usingthe information listed above.Please help! The is a physics problem, but Im hoping someone here might be able to help.> Im trying tofind the tangential velocity of a body (mass: .127kg), ying> around in a circle from a string of unknown length. The radius is the circle> is .43m, and using an astrolabe, I found the angle to be 58 degrees.The angle of *what* is 58 deg? And it sounds like regardless of thedetail of the string setup, the object ultimately moves in acircle of radius 0.43m. So just measure the time it takes forthe object to go around the circle, and the tangential velocityis then simply (0.43m*2pi)/T.If you cant measure the time, then try to describe the problembetter. One end of the string is apparently attached to theobject. What is the other end attached to? Is that mountpointmoving? If so, how is it moving? And where does the 58 degree anglet in to all that?-- Rich Carreiro rlcarr@animato.arlington.ma.us > The is a physics problem, but Im hoping someone here might be able to help.> Im trying tofind the tangential velocity of a body (mass: .127kg), ying> around in a circle from a string of unknown length. The radius is the circle> is .43m, and using an astrolabe, I found the angle to be 58 degrees.>> The angle of *what* is 58 deg? And it sounds like regardless of the> detail of the string setup, the object ultimately moves in a> circle of radius 0.43m. So just measure the time it takes for> the object to go around the circle, and the tangential velocity> is then simply (0.43m*2pi)/T.>> If you cant measure the time, then try to describe the problem> better. One end of the string is apparently attached to the> object. What is the other end attached to? Is that mountpoint> moving? If so, how is it moving? And where does the 58 degree angle> t in to all that?Already answered on sci.physics and sci.physics.relativity.Dirk Vdm =answer.> The is a physics problem, but Im hoping someone here might be able tohelp.> Im trying tofind the tangential velocity of a body (mass: .127kg),ying> around in a circle from a string of unknown length. The radius is thecircle> is .43m, and using an astrolabe, I found the angle to be 58 degrees.>> The angle of *what* is 58 deg? And it sounds like regardless of the> detail of the string setup, the object ultimately moves in a> circle of radius 0.43m. So just measure the time it takes for> the object to go around the circle, and the tangential velocity> is then simply (0.43m*2pi)/T.>> If you cant measure the time, then try to describe the problem> better. One end of the string is apparently attached to the> object. What is the other end attached to? Is that mountpoint> moving? If so, how is it moving? And where does the 58 degree angle> t in to all that?>> Already answered on sci.physics and sci.physics.relativity.>> Dirk Vdm>> Of course its not. But it seems to me that his skepticism regarding>whether that proof _can_ be formalized must in fact be skeptism>regarding whether its possible to state all the necessary axioms>and deduce the theorem without any appeal to the way things>look.As I have stressed in my other post, Im *not* skeptic about the factthat that proof can be formalized!Im simply puzzled thinking of how it would be done, since IMHO it isa proof that indeed *does* make heavily appeal to the way things look,and in this sense it is so simple that often one canfind it inpopularization books.(BTW) Also, since you mentioned axiomatic euclidean geometry, I justdont know anything about it[*], but I dont know wether it ispossible in its formalism to dene/talk about continuoustransformations, that are indeed the basis of that proof.So, if I am right in my assumption above, while the object of theproof can be reasonably dened in axiomatic euclidean geometry,either the theorem cant be proved in that teory or there exists analternative proof that does not use continuity arguments.[*] This means: so I may well be wrong!Michele-- > Comments should say _why_ something is being done.Oh? My comments always say what _really_ should have happened. :)- Tore Aursand on comp.lang.perl.misc =Could someone please give me a proof for distributive law of the crossproduct:a x (b + c) = a x b + a x cBut theres a catch! I am assuming the we have dened the crossproduct as (|a||b|sinO)n, etc. Using the above proof (that is, takingthe above as true) THEN I will use the above truth to derive therectangular form of the cross product. So I need the above provedwithout resorting to the rectangular form/defn of the cross product.Thanx in advanceMB =Could someone please give me a proof for distributive law of the cross> product:a x (b + c) = a x b + a x cBut theres a catch! I am assuming the we have dened the cross> product as (|a||b|sinO)n, etc. Using the above proof (that is, taking> the above as true) THEN I will use the above truth to derive the> rectangular form of the cross product. So I need the above proved> without resorting to the rectangular form/defn of the cross product.> Proof it for the canonical unit vectors e1, e2, e3. This is easy,there are only a few cases to consider.Then set a = a1*e1 + a2*e2 + a3*e3 where a1, a2, a3 are the coodinatesof a. The same for b and c and see what you can get. Probably it isuseful to do the case rst where a is one of the canonical unitvectors and only b and c are arbitrary. =If we visualize a cubic graph (with 2n vertices and 3n edges) as anetwork of water pipes, and if water is owing through the pipes in aclosed system, then the ows through each of the edges must satisfythe condition that the ows into any vertex are equal to the owsout. This leads to a set of 2n equations in 3n unknowns which must besatised by any ow. At least one of these 2n equations is impliedby the rest, since the sum of all the equations is 0, thus the rank ofthe system of equations is at most 2n-1. Ive tested all bridgefreeregular cubic graphs up to n=7 and it appears that for these graphs,the rank is always exactly equal to 2n-1. Is this true in general, orare there counterexamples, or is it an open question? If we visualize a cubic graph (with 2n vertices and 3n edges) as a> network of water pipes, and if water is owing through the pipes in a> closed system, then the ows through each of the edges must satisfy> the condition that the ows into any vertex are equal to the ows> out. This leads to a set of 2n equations in 3n unknowns which must be> satised by any ow. At least one of these 2n equations is implied> by the rest, since the sum of all the equations is 0, thus the rank of> the system of equations is at most 2n-1. Ive tested all bridgefree> regular cubic graphs up to n=7 and it appears that for these graphs,> the rank is always exactly equal to 2n-1. Is this true in general, or> are there counterexamples, or is it an open question?Form a cycle basis of the graph: take a spanning tree (2n-1) edges) and form n+1 cycles by using each remaining edge together with the path connecting its endpoints in the tree.You can form a ow (circulation) in the graph by choosing for each cycle a ow that is zero elsewhere, and adding these cycles.Conversely any ow is the sum of ows on the cycles in a unique way determined by the ow values on the non-tree edges.So the space of ows has dimension exactly n+1, as a subspace of the 3n-dimensional space of independent ow amounts on edges, and the system of ow conditions has rank exactly 2n-1.This can all be viewed as doing basic homology theory on the graph...-- David Eppstein http://www.ics.uci.edu/~eppstein/Univ. of California, Irvine, School of Information & Computer Science =James Harris [...]-- G.C. =What is the interpretation on z_1*z_2 = ln z_1 + ln z_2on a complex plane? Is it true thatfor any ln z_1 and any ln z_2 exists ln z_1*z_2 such thatln z_1*z_2 = ln z_1 + ln z_2 ?If not, what the rst order logic statement is correct, then? What is the interpretation of>ln z_1*z_2 = ln z_1 + ln z_2>on a complex plane? Is it true that>for any ln z_1 and any ln z_2 exists ln z_1*z_2 such that>ln z_1*z_2 = ln z_1 + ln z_2 ?In this case that does happen to be true, because different branchesof ln(z) differ by a multiple of 2 pi i. Or you could choose, say, values of ln z_1 and ln(z_1 z_2) and get a value of ln z_2.On the other hand, a statement such as ln z^2 = 2 ln z is trickier: every value of the right side is a value of the left side, but not every value of the left side is a value of the right side. IMHO it wouldbe better to writeln (z_1 z_2) = ln(z_1) + ln(z_2) + 2 pi i n for some integer nwhich is true no matter what branches you choose for all the logarithms.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 What is the interpretation of>>ln z_1*z_2 = ln z_1 + ln z_2>>on a complex plane? Is it true that>>for any ln z_1 and any ln z_2 exists ln z_1*z_2 such that>>ln z_1*z_2 = ln z_1 + ln z_2 ?>> In this case that does happen to be true, because different branches> of ln(z) differ by a multiple of 2 pi i. Or you could choose, say,> values of ln z_1 and ln(z_1 z_2) and get a value of ln z_2.> On the other hand, a statement such as ln z^2 = 2 ln z is trickier:> every value of the right side is a value of the left side, but not every> value of the left side is a value of the right side. IMHO it would> be better to write>> ln (z_1 z_2) = ln(z_1) + ln(z_2) + 2 pi i n for some integer n>> which is true no matter what branches you choose for all the logarithms.Could the identityln (z_1 z_2) = ln(z_1) + ln(z_2)be somehow interpreted in terms of Riemann Surfaces, without referring tobranches and multivalued functions? Could the identity>> ln (z_1 z_2) = ln(z_1) + ln(z_2)>> be somehow interpreted in terms of Riemann Surfaces, without referring to> branches and multivalued functions?Or to put it bluntly, can I add Riemann Surfaces? =I left the quotes that are not just silly, but it has to be saidthat a)Bucky *did* use at least one mathematicians work, Coxeters, and b)_S_ is not a textbook of math, and contains no proofs. as I said,nothing more difcult than deploying the pythagorean theorem -- andhere are two things that are even useful, sinceI realized that they could be magnied:http://www.rwgrayprojects.com/synergetics/plates/gs /plate02.htmlhttp://www.rwgrayprojects.com/synergetics/plates /gs/plate01.htmlthe words about co-ordinate systems are ne, but, then,Bucky was also entirely correct about the importanceof the IVM, the dual of the net of packed rhombical dodecahedra;yes, trigonal or hexagonal tiling of hte plain is equivalentto doing it with tetragona (skwares), but it misses the point. as for Synergetics co-ordinates,Bucky didnt ever nd what he was looking for, as faras i can tell, and Nelson (so far) has only come-upwith a kind of homogenous co-ordination --which is awfully obfuscated in his Wolframite layout, ifthats what it is. (actually,trigonal co-ordinates are inherently homogenous in the plain,unless you just ignore one of the sets of lines, andthink of the as oblique (cartesian) ones.) > (1) http://www.rwgrayprojects.com/synergetics/synergetics.html> (2) http://www.mathforum.org/epigone/geometry-research> (3) http://library.wolfram.com/infocenter/MathSource/600> (4) http://mathworld.wolfram.com/SynergeticsCoordinates.html > fundamental structure of the plane is hexagonal) that sound wonderful > but have no meaning. In fact its a mere matter of convenience whether > we use orthogonal or hexagonal coordinates - neither is intrinsically > better than the other; its just that some coordinate-systems are better > suited to some problems than others. Ive used dozens of different > I agree with you that Fuller was under no obligation to study earlier > work. But if he had done so, his writings might have been much more > ...Fuller gives plenty of evidence of not knowing what a proof is, and > As I said, Fullers writings on geometry are meaningful and probably > usually correct. But let me assure you that you would have gained so > much more by reading geometry from a more sensible source. --UN HYDROGEN (sic; Methanex (TM) reformanteurs) ECONOMIE?...La Troi Phases dExploitation de la Protocols des Grises de Kyoto:(FOSSILISATION [McCainanites?] (TM/sic))/BORE/GUSH/NADIR @ http://www.tarpley.net/aobook.htm.Http://www.tarpley.net/ bushb.htm (content partiale, below): 17 -- LATTEMPTER de COUP DETAT, 3/30/81 =oops; let me see if I can get those excerpts seperatedby whitespace. but heres the best one by JHC-- and very true, ye olde Bucky Witches --which Nelson cleverly put at the end:As I said, Fullers writings on geometry are meaningful and probably usually correct. But let me assure you that you would have gained so much more by reading geometry from a more sensible source. > http://www.rwgrayprojects.com/synergetics/plates/gs/plate01. html > Bucky didnt everfind what he was looking for, as far> as i can tell, and Nelson (so far) has only come-up> with a kind of homogenous co-ordination --> which is awfully obfuscated in his Wolframite layout, if> thats what it is. (actually,> trigonal co-ordinates are inherently homogenous in the plain, > (1) http://www.rwgrayprojects.com/synergetics/synergetics.html > (4) http://mathworld.wolfram.com/SynergeticsCoordinates.html fundamental structure of the plane is hexagonal) that sound wonderful > but have no meaning. In fact its a mere matter of convenience whether > we use orthogonal or hexagonal coordinates - neither is intrinsically > better than the other; its just that some coordinate-systems are better > suited to some problems than others. Ive used dozens of different > I agree with you that Fuller was under no obligation to study earlier > work. But if he had done so, his writings might have been much more > ...Fuller gives plenty of evidence of not knowing what a proof is, and --Dec.2000 WAND Chairman Paul ONeill, reelected to Board. Newsish?http://www.rand.org/publications/randreview/issues/rr .12.00/http://members.tripod.com/~american_almanac oops; let me see if I can get those excerpts seperated> by whitespace. but heres the best one by JHC> -- and very true, ye olde Bucky Witches --> which Nelson cleverly put at the end:> As I said, Fullers writings on geometry are meaningful and probably> usually correct. But let me assure you that you would have gained so> much more by reading geometry from a more sensible source.I suppose that Synergetics is internally consistent.It is signicant ( to me, at least) that nobody I ever met who thinksthat Synergetics is a Mathematic Masterpiece, knows any Mathematics whateverbeyond CalcI, if that.Although I have a small sample of his audience, I fell safe to state that heis probably a guru with Mensa-type numerologists.RJ Pease =Bob, can I call you, Dickhead? seriously,it isnt difcult to read, if you just peruse itby the pictures that appeal to you, andignore the run-on language. you can just as well begin with _S2_, ifyou canfind a copy at your library, as wellas _S1_, if you dont want use the combined online thing. but, yes, you are referring to whom I call Bucky Witches,wich is what a gaggle of them called themselves,when I met them at a local modelling workshopput on by Amy Edmundson. oh, ****;search for *her* book, which is also online,for a fabulously concise accounting of the math.Bucky didnt fall for numerology at all, althoughhe came close with the Scheherezade numbers,which you canfind in _S_. > Although I have a small sample of his audience, I fell safe to state that he> is probably a guru with Mensa-type numerologists.--les ducs dEnron! =as someone whos actually read _S_, but who left both volumesat a library, since its really quite simple-- nothing more difcult than the pythagorean theorem is needed --and I can always get the online edition, I have to saytaht Conways comments are primarily irrelavent prattle (butIll review them, when I get the chance). one can take issue with a lot of things (as I just did,below), as I do with his so-called a-political practice, andsome of his speculative prehistory, or with his cute waywith English, but I dont care. he actaully has made some dyscoveriesthat are incredibly important (or just very basic; hey).thus quoth: discussion of Buckminster Fullers works in other words, if youre really into it,get an elementary book on numbertheory, orits basically hopeless. truly fascinating,once you can stand it!--UN HYDROGEN (sic; Methanex (TM) reformanteurs) ECONOMIE?...La Troi Phases dExploitation de la Protocols des Grises de Kyoto:(FOSSILISATION [McCainanites?] (TM/sic))/BORE/GUSH/NADIR @ http://www.tarpley.net/aobook.htm.Http://www.tarpley.net/ bushb.htm (content partiale, below): 17 -- LATTEMPTER de COUP DETAT, 3/30/81 > Here are some quotes of John Horton Conway about R. Buckminster Fullers > books Synergetics: an exploration in the geometry of thinking, and > Synergetics 2 (see 1), from geometry-research (see 2). All of the quotes > are completely out of context; you cant tell what he was replying to.> Do mathematicians follow JHC like he said some people follow RBF?Its nice to see that JSH isnt the only outsider persecuted byestablishment mathematicians. =Clifford J. Nelson> Here are some quotes of John Horton Conway about R. Buckminster Fullers> books Synergetics: an exploration in the geometry of thinking, and> Synergetics 2 (see 1), from geometry-research (see 2). All of the quotes> are completely out of context; you cant tell what he was replying to.>> Ill bet a lot of people wont read the Mathematica notebook> SynergeticsApplication7 (see 3), or see anything new or worthwhile in> the mathworld entry on synergetics coordinates (see 4) because of the> answer to the question below.No argument there.This Synergetics cult, and others like it, might have fewer followers if themasses were better educated about simple stuff like coordinates andtesselations. On the other hand, there will always be zealots, and peoplewho, owing to vanity, subscribe to whatever would-be super-theory is aucourant.The word cybernetics came massively into fashion in the 50s; maybe thesetwo coinages were attempts to cash in on it.Enough of this crap:)LH =[SNIP - mersennes]> I also wonder about y^n + 1 and about y! - 1 or y! + 1 being prime.> And eh, another thing I wonder is if there have been experiments wiht> representing primes in a different system than the decimal system (for> instance a kind of system where each digit is 2*previous_digit^2 in value.> And lastly I also wonder if there have been any theories on correlations> between prime number dispersion (I cant think of the right word) and> fractals, or any complex iteration model.By similar arguments, if y^n + 1 is prime, then y = 2 and n = 2^k. The> numbers 2^2^k + 1 are Fermat numbers, and only ve of them are proved> primes, for k = 0, 1, 2, 3 and 4. For k = 5 to 25 or more (tha last a big> number), they are composite.Y need not be 2.Daniel Heuers recent 1372930^2^17+1 is prime (and huge, the 5th largest in the world presently at 804474 digits)These are called Generalised Fermat Numbers, of just GFNs.http://primes.utm.edu/top20/page.php?id=3Phil-- Unpatched IE vulnerability: history.back method cachingDescription: cross-domain scripting, cookie/data/identity theft, command executionExploit: http://www.safecenter.net/liudieyu/RefBack/RefBack-MyPage.HTM =Phil Carmody escribi.97 1 and about y! - 1 or y! + 1 being prime.> And eh, another thing I wonder is if there have been experiments wiht> representing primes in a different system than the decimal system (for> instance a kind of system where each digit is 2*previous_digit^2 invalue.> And lastly I also wonder if there have been any theories oncorrelations> between prime number dispersion (I cant think of the right word) and> fractals, or any complex iteration model.>> By similar arguments, if y^n + 1 is prime, then y = 2 and n = 2^k. The> numbers 2^2^k + 1 are Fermat numbers, and only ve of them are proved> primes, for k = 0, 1, 2, 3 and 4. For k = 5 to 25 or more (tha last abig> number), they are composite.>> Y need not be 2.>> Daniel Heuers recent 1372930^2^17+1 is prime> (and huge, the 5th largest in the world presently at 804474 digits)>> These are called Generalised Fermat Numbers, of just GFNs.>> http://primes.utm.edu/top20/page.php?id=3>> Phil>Of course, I mismatch the statements. The correct statement is:2^n + 1 is an odd prime > n = 2^kI apologize ...-- Ignacio Larrosa Ca.96estroA Coru.96a (Espa.96a)ilarrosaQUITARMAYUSCULAS@mundo-r.com [SNIP - mersennes]>> By similar arguments, if y^n + 1 is prime, then y = 2 and n = 2^k. The>> numbers 2^2^k + 1 are Fermat numbers, and only ve of them are proved>> primes, for k = 0, 1, 2, 3 and 4. For k = 5 to 25 or more (tha last a big>> number), they are composite.>Y need not be 2.>Daniel Heuers recent 1372930^2^17+1 is prime >(and huge, the 5th largest in the world presently at 804474 digits)>These are called Generalised Fermat Numbers, of just GFNs.Or for smaller examples, try 6^2+1, 6^(2^2)+1, 10^2+1, 14^2+1,20^2+1, 20^(2^2)+1. Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 I also wonder about y^n + 1 and about y! - 1 or y! + 1 being prime.>and snoozing 4! + 1 = 25; 5! + 1 = 121; 6! + 1 = 721are compositey! - 1 however is more interesting. I will answer your questions below up here.> I dont like the idea of using a real value in the vector elds.> I believe that they should be unsigned magnitudes.> To impose a sub-sign seems incoherent to me.> I admit that the math still works out but its like buildng the reals> from the reals.> I agree there are some odd discontinuities as a path passes between> the thirds of the plane (three-signed).> If for example you look at a graph of the unit circle in the> three-signed domain for one third of the plot each sign has zero> component in the reduced form:star(theta)> ^> |. .> | . .> | . .> | . .> | . .> | . .> | . . > | ............. > ------------------------------------>theta> 0 2pi/3 pi 4pi/3 2piThis is a crude graph of the star component of the unit circle versus> theta.> The star pole is at theta equals zero.Still, even with these discontinuities the math matches the complex> numbers for sum and product.So I guess the four-signed product doesnt ring any bells?> I still havent managed the transform with all of its triginometry.> I can understand the desire to work in vectors. The philosophy of what> we are doing is still polysigned numbers.Just an observation: these arent discontinuities in the sense used in calculus. The derivative, however, has two discontinuities.-- Will Twentyman =160 years ago today, on October 16, 1843, mathematician W. R. Hamiltoninvented quarternions, also known as hypercomplex numbers. He beganby postulating a second imaginary, j, whose square is -1, but which isnot equal to i. He then proved:1) that the product of i x j must be a third imaginary, k, whosesquare is also -12) multiplication of quarternions is not commutative (e.g., i x j = -j x i). W. R. Hamilton invented... hypercomplex numbersBeing currently enrolled for a course in Complex Analysis, i strongly opose to that theory. For once, id like to know it all without a next bigger idea awaiting. :)-- KindlyKonrad------------------------------------------------- places;their souls be chased by demons in Gehenna from one room toanother for all eternity and more.Sleep - thing used by ineffective people as a substitute for coffeeAmbition - a poor excuse for not having enough sence to be lazy--------------------------------------------------- 160 years ago today, on October 16, 1843, mathematician W. R. Hamilton> invented quarternions, also known as hypercomplex numbers.Who actually uses these numbers?I mean, ordinary complex numbers are abundant, even in engineering. Buthypercomplex? Are they related to Minkowski space, i.e. special relativity(simply because the dimension is four). Are they used in theoretical physicsotherwise?I seem to remember some eight-dimensional numbers too (Cayley?), but thenyoud lose either the associative or distributive law, I forget which. Arethey of any use?And thats it. Apparently, you cannot go into higher dimension, and stillretain familiar properties. What is the signicance of that fact?-Michael. 160 years ago today, on October 16, 1843, mathematician W. R. Hamilton>>invented quarternions, also known as hypercomplex numbers.Who actually uses these numbers?>>I mean, ordinary complex numbers are abundant, even in engineering. But>hypercomplex? Are they related to Minkowski space, i.e. special relativity>(simply because the dimension is four). Are they used in theoretical physics>otherwise?>>I seem to remember some eight-dimensional numbers too (Cayley?), but then>youd lose either the associative or distributive law, I forget which. Are>they of any use?>>And thats it. Apparently, you cannot go into higher dimension, and still>retain familiar properties. What is the signicance of that fact?>>-Michael.>Arent quaternions used in number theory? (A sincere question - I dont really know.) Plus they provide a canonical example of a skew eld.-- Stephen J. Herschkorn herschko@rutcor.rutgers.edu Arent quaternions used in number theory? (A sincere question - I dont >really know.) Plus they provide a canonical example of a skew eld.They can be used to prove that every positive integer is a sum of four squares (see e.g. Herstein, Topics in Algebra, sec. 7.4).On the other hand, Lagrange proved that theorem long before quaternionswere invented.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 160 years ago today, on October 16, 1843, mathematician W. R. Hamilton> invented quarternions, also known as hypercomplex numbers.Who actually uses these numbers?I mean, ordinary complex numbers are abundant, even in engineering. But> hypercomplex? Are they related to Minkowski space, i.e. special relativity> (simply because the dimension is four). Are they used in theoretical physics> otherwise?I probed that question a bit when I rst learned about hypercomplexnumbers while I was an undergraduate. A classmate of mine, who hadknown about hypercomplex numbers for awhile, said that WernerHeisenburg had originally used them in his matrix formulation ofwas wrong, and Heisenburg proceeded to redo his matrix formulationusing ordinary imaginary numbers. Since then, as far as we coulddetermine, nobody had used them for anything.The bottom line is that theres no guarantee a mathematical conceptwill prove useful just because we can conceive it. But Im not awarethat ordinary complex numbers had any apparent practical use when theywere rst formulated, either. I think Heisenburg had the right idea,even though his theory turned out to be wrong: If youfind somethingunexplained, at least consider what would happen if hypercomplexnumbers were involved and see whether this would explain anything. Itmay not. But, then again, it may!Bob > 160 years ago today, on October 16, 1843, mathematician W. R. Hamilton> invented quarternions, also known as hypercomplex numbers.> Who actually uses these numbers?> I mean, ordinary complex numbers are abundant, even in engineering. But> hypercomplex? Are they related to Minkowski space, i.e. special relativity> (simply because the dimension is four). Are they used in theoretical physics> otherwise?> =Michael Jrgensen> 160 years ago today, on October 16, 1843, mathematician W. R. Hamilton> invented quarternions, also known as hypercomplex numbers.>> Who actually uses these numbers?>> I mean, ordinary complex numbers are abundant, even in engineering. But> hypercomplex? Are they related to Minkowski space, i.e. special relativity> (simply because the dimension is four). Are they used in theoreticalphysics> otherwise?Physicists tend to use spinors instead of quaternions, i.e. pairs of complexnumbers instead of quadruples of real numbers. Quaternions are used insoftware for rendering, if that counts for anything.>> I seem to remember some eight-dimensional numbers too (Cayley?), but then> youd lose either the associative or distributive law, I forget which. Are> they of any use?Cayleys octonians, which are not associative. They are the prototype ofalternative algebras, which have developed a little in recent times....LH Im looking for a reference for the proof that the innite seriesAs for a reference, the proof appears in many elementarycalculus texts, and in almost any text covering Fourierseries.There is an entirely elementary proof of this relation,which I suspect is well known but Ive never seen it.Factor (1+x)^N - (1-x)^N, for N an odd integer, asproduct ( w^k(1+x) - w^{-k}(1-x) ), k=-(N-1)/2..(N-1)/2where w = exp( i pi / N )Thenfind the coefcient of x^3 for that expression, andcompare it to the same coefcient using the Binomial Theoremfor the rst expression, and take a limit. Thats a different it. If you apply Parseval to the function x on> [-pi,pi] you get the sum of 1/n^2. If you use the convergence> of the Fourier series for x^2 you also get the sum of 1/n^2 > coming out. =I have a concept about trying to map 3-D coordinates to the plane. My idea is to divide the plane into three sections, radially about theorigin. Thus the x axis is to be represented in the area swept by theangle [0, 2/3 pi], the y axis in the area swept by the angle [2/3 pi,4/3 pi], and the z-axis in the area of [4/3 pi, 2 pi], as an example.Then I gure to bisect each angle and represent positive values inone section of the angle and negative values in the other section. x-/y+ / x+----0-------y- / z- / z+Then a three dimensional point x, y, z, is one to three points on theplane. For example (0, 0, 0) is mapped to (0, 0), non-zero (x, y, z)is mapped to polar coordinates ( r(x), theta(x)), ( r(y), theta(y)),and (r(z), theta(z)).A part of that is that where x is real then for positive x it ismapped to (x, pi/6) for positve x and (x, pi/2) for negative x.Connecting the points of non-zero t(x, y, z) would form a triangle. Then something like a 3-d polygon would be the interconnection of eachof the points mapped into the 2-d space.I got this notion and it is mostly that, Im trying to gure out ameaningful way to map n-d coordinates to the plane, in this case wheren=3. It might only be useful where for n that a regular polygon of 2nsides tiles in the plane.Im hoping that you can tell me something about mathematical enquiryand practice into representing 3-d or generally n-d objects fully in2-d.Ross F. =Im not so sure what you mean,butwhy not make positive & negative sectors,opposite from each other?> I have a concept about trying to map 3-D coordinates to the plane. My idea is to divide the plane into three sections, radially about the> origin. Thus the x axis is to be represented in the area swept by the> angle [0, 2/3 pi], the y axis in the area swept by the angle [2/3 pi,> 4/3 pi], and the z-axis in the area of [4/3 pi, 2 pi], as an example.Then I gure to bisect each angle and represent positive values in> one section of the angle and negative values in the other section.> x-/> y+ / x+> ----0-------> y- / z-> / z+Then a three dimensional point x, y, z, is one to three points on the> plane. For example (0, 0, 0) is mapped to (0, 0), non-zero (x, y, z)> is mapped to polar coordinates ( r(x), theta(x)), ( r(y), theta(y)),> and (r(z), theta(z)).--Dec.2000 WAND Chairman Paul ONeill, reelected to Board. Newsish?http://www.rand.org/publications/randreview/issues/rr .12.00/http://members.tripod.com/~american_almanac =Youre not mapping 3-d to 2-d, but rather space to either the powerset of the plane or the cartesian product of three copies of theplane. Ive never heard of anything like this being done, and I donot think that further inquiry would benecial.> Connecting the points of non-zero t(x, y, z) would form a triangle. You will not always get a triangle. If two coordinates are 0, thenyou will get a line segment.> Then something like a 3-d polygon would be the interconnection of each> of the points mapped into the 2-d space.Im not sure if I understand what this means. Heres what I think itmeans. We have a point (x,y,z) in 3-d. You map this point to thethree points (x,theta(x)), (y,theta(y)), and (z,theta(z)). Then drawthe three line segments connecting these three points. The problemis that in general, these line segments contain points that are notmapped to by any point in 3-d. So it is rather meaningless (anduntrue) to say that this is a 3-d polygon. But, admittedly, I dontbelieve I understand what you meant. ~ Chris =Im not quite sure if what I had in mind was any use either, but atthe time it seemed to be some kind of intellectually soothing insightabout itself: mapping 3-d points onto a plane.In mapping the 3-d point to the 3 2-d points, they may coincide, asyou say, for (x, y, z) if any two points equal zero than there wouldonly be two points to represent it on the plane. The 3-d origin isuniquely represented by the 2-d origin.In drawing the lines among the 3 points that represent one point,basically the idea is that that triangle, or rather the set of itsvertices, represents one 3-d point. Consider (1, 1, 1). It would mapto polar (1, pi/6), (1, 5pi/6) and (1, 9 pi/6). Adding 2pi/3 to eachof those angles would yield the points on the plane which map back to(1, 1, 1). For the coordinates that represent (2, 1, 1), the sameaddition to each polar coordinates angle would represent (1, 2,1). Ina way that change would represent a change from the 3-d coordinaterepresenting a 2x1x1 rectangular solid to a 1x2x1 rectangular solid,for width, length and depth swapping width and length. Thats quitemore directly done by exchanging the x and y coordinates.I was trying to think how something like a polyhedron in 3 dimensionwould be represented. It could be a list of its vertices in 3-d, or alist of the triples of 2-d coordinates for 2-d.I noticed on the little ASCII diagram after I sent it that it lookslike a perspective drawing of the x, y, and x axes except the labelsare different, with the positive axis being orthogonal to the negativeaxis, and x+ || (parallel to) y-, y+ || z-, and z+ || x-.Going back to 2 3-d points mapped into the 2-d points, each wouldrepresent a set of one, two, or three points. Connect each pair ofpoints, some may cross, thus forming multiple polygons.A large problem with this is plotting 2-d points wth z considered tobe zero into the construction. For example, a straight line segmentfrom (1, 0) to (-1, 0) would be plotted as two adjoining line segmentsfrom (1, theta(x+)) to the origin and from there to (1, theta(x-)). What concerns me more are what would end up being plotted as separatedline segments. For example the 2-d point (1, 1, 0, ...)would beplotted as the set of two points (1, theta(x+)) and (1, theta(y+)),instead of just one point. Im not saying that this is a problemspace, just that it might be interesting.This might be something where making a bunch of these little plots andseeing how they represent things that have utility without beingmutlilated would be. As well, I should draw regular polygons of theplane onto it and see what they could represent if they were 3-dpoints represented on the plane this way.The equilateral triangle with its center at the origin and to havedistance from its center to each vertex being equal to one would havevertexes representing (1, 1, 1). The lines of the triangle also passthrough some (-x, theta(-x)), (-y, theta(-y)), and (-z, theta(-z)),where x, y, and z are equal and the length of the segment from theorigin to the midpoint of the side of the equilateral triangle withdistance from the center(centroid) to the vertex of 1. Here it iskeen to have a protracter, which I have misplaced. The trianglebreaks into six 30-60-90 triangles, with hypotenuse of length one. Its been a while since I have thought of this kind of thing. Thelines of the equilateral triangle would pass through (1/ 2,theta(x-)), etcetera, (-1/2, -1/2, -1/2).Anyways, how about drawing a box from 3-d with corners of +-1, thathas volume 8 and area 6 x 4. I gure to determine where each pointof te line segments connecting the vertices is marked on the 2-d plot. On each of the six radial rays the point at distance from the origin1 is marked, as is that of 1/2, 1/4, and each point between the originand 1, the cube symmetric about the origin with faces parallel to thexy, yz, and zx planes plots in the 2-d plane as a set of three linesegments from (1, theta(x+)) to (1, theta(y-)), from (1, theta(y+)) to(1, theta(z-)), and from (1, theta(x+)) to (1, theta(x-)), each minusthe origin. A problem here is recovering the cube from the plot,there may well be other 3-d polyhedra that have the same plot, forexample all polyhedra with vertices (+-1, +-1, +-1) with no vertex (x,y, z) with |x| (absolute value), |y|, or |z| greater than 1.Im trying to gure out a tractable sphere in cartesian coordinatesto get a plot. A sphere centered on the origin x^2+y+2+z^2=1 as anexample would perhaps also have the same plot as the cube above.Ill think about this some more and try and gure out if there isanything useful about it, it might be a waste of time but I tend totrust my instincts.Heh, cubing the sphere.Besides real coordinates x, y, z, Im also considering complexcoordinates x, y, z. For example where the angle is between that ofx+ and x-, at distance r from the origin, on the x+ side it would be0-ri and on the x- side it would be 0+ri.Im not too worried about this. Ross =Im trying to solve a puzzle. Its a cube with parts that move NOT like aRubics cube. I need a method to tell me if certain positions are reachablethrough the allowed manipulations from a starting conguration. Here is asimple sub problem.At one point along the way, Ive got four corners oriented like this:A BD CI can x any corner, and rotate the other three. For example, xing A Ican reach:A DC BthenA CB DthenA BD Cthe original.After ddling with this for a while I decided that I can not reach:A BC DThere seem to be two sets of congurations, one reachable fromA BD Cand one reachable fromA BC DIt seems there must be a property, e.g. left vs right, that is different forthe two groups and conserved by the manipulation. How can I dene andcompute such a property for a given conguration? How do I know it will beconserved by the manipuation?Ive tried looking at displacements from starting position in terms ofrotations and/or horizontal and vertical ips. I dontfind anything easy.If I learn how to dene simple symmetry properties, I will be able to do sofor larger problems within the puzzle. That will save me considerable timeddling in an attempt to achieve the impossible.John Im trying to solve a puzzle. Its a cube with parts that move NOT like a> Rubics cube. I need a method to tell me if certain positions are reachable> through the allowed manipulations from a starting conguration. Here is a> simple sub problem.At one point along the way, Ive got four corners oriented like this:> A B> D CIf this is a physical square object, why cant you perform A BD C->D AC B?Do the faces have some kind of orientation?> I can x any corner, and rotate the other three. For example, xing A I> can reach:> A D> C Bwhich, if the above rotation is permitted, is D B A Cso you can swap A and D. Therefore you can swap any neighbouring corners. Therefore you can swap C and D.> then> A C> B Dthen> A B> D C> the original.After ddling with this for a while I decided that I can not reach:> A B> C DWhats wrong with xing D:A B D C->C AD B=A BC DPhil-- Unpatched IE vulnerability: Notepad popupsDescription: Opening popup windows without scriptingReference: http://computerbytesman.com/security/ notepadpopups.htmFollowup: http://msgs.securepoint.com/cgi-bin/get/bugtraq0308/55.html== = If this is a physical square object, why cant you perform> A B> D C> ->> D A> C B> ?>> PhilBecause of relationships between these corners and other parts of the faceand other faces of the cube.You are right, if I could perform the 90 degree rotation, then I cold reachany conguration.P.S.Im using Outlook Express to read and reply to this newgroup atnews.ucr.edu. It wouldnt let my response include more of the originalmessage than new text that I added! Ever heard of such a thing? DidOutlook express do that, or did my news server do that. What is a goodnewsreader for Windows? Im trying to solve a puzzle. Its a cube with parts that move NOT like a>Rubics cube. I need a method to tell me if certain positions are reachable>through the allowed manipulations from a starting conguration. Here is a>simple sub problem.>At one point along the way, Ive got four corners oriented like this:>A B>D C>I can x any corner, and rotate the other three. For example, xing A I>can reach:>A D>C B...>There seem to be two sets of congurations, one reachable from>A B>D C>and one reachable from>A B>C D>It seems there must be a property, e.g. left vs right, that is different for>the two groups and conserved by the manipulation. How can I dene and>compute such a property for a given conguration? How do I know it will be>conserved by the manipuation?Yes. A permutation is odd if it is the product of an oddnumber of transpositions, and even if it is the product of aneven number of transpositions. Your rotations are 3-cycles, whichare products of two transpositions and thus even, e.g.AB AB ADDC to CD to CB.The product of even permutations is even, so you can only performeven permutations, and not odd permutations.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 =Robert,original text in my replies.Now, when I attempt to apply this idea to larger problems, Ive got morequestions.My transpositions were of objects in adjacent positions. However, yourstatement holds even if the transpositions are not adjacent, true?My list had four objects in four positions, and also position 1 was adjacentto position 4. Your statement holds true regardless the size of the listand regardless of whether the rst and last positions are adjacent, true?Is there a way that can I compute the oddness or evenness of a congurationwithout having to actually transpose it back to the desired position andcounting the number of transpositions needed? For example if I call (ABCD)even, then how can I know in one step that (DCBA) is also even? My transpositions were of objects in adjacent positions. However, your>statement holds even if the transpositions are not adjacent, true? True>My list had four objects in four positions, and also position 1 was adjacent>to position 4. Your statement holds true regardless the size of the list>and regardless of whether the rst and last positions are adjacent, true?True>Is there a way that can I compute the oddness or evenness of a conguration>without having to actually transpose it back to the desired position and>counting the number of transpositions needed? For example if I call (ABCD)>even, then how can I know in one step that (DCBA) is also even?Use disjoint cycle notation. For example, the permutation taking ABCDto DCBA consists of the cycles [AD][BC] so its even. Or the permutation taking ABCDEFG to DBACGFE is [ADC][B][EG][F] (i.e. A goes to D, which goes to C, which goes back to A, B goes to itself, E goes to G which goes to E, F goes to itself). Any permutationcan be written as a product of disjoint cycles; an n-cycle is odd ifn is even and even if n is odd. So [ADC][B][EG][F] is even*even*odd*even= odd.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 Im trying to solve a puzzle. Its a cube with parts that move NOT like a> Rubics cube. I need a method to tell me if certain positions are> reachable> through the allowed manipulations from a starting conguration. Here is> a simple sub problem.At one point along the way, Ive got four corners oriented like this:> A B> D CI can x any corner, and rotate the other three. For example, xing A I> can reach:> A D> C Bthen> A C> B Dthen> A B> D C> the original.After ddling with this for a while I decided that I can not reach:> A B> C DThere seem to be two sets of congurations, one reachable from> A B> D C> and one reachable from> A B> C DIt seems there must be a property, e.g. left vs right, that is different> for> the two groups and conserved by the manipulation. How can I dene and> compute such a property for a given conguration? How do I know it will> be conserved by the manipuation?Ive tried looking at displacements from starting position in terms of> rotations and/or horizontal and vertical ips. I dontfind anything> easy. If I learn how to dene simple symmetry properties, I will be able> to do so> for larger problems within the puzzle. That will save me considerable> time ddling in an attempt to achieve the impossible.John-- Transformations of the square can be represented by the subgroup of S_4 (the symmetric group on four letters) generate by 3-cycles. The question is, what is the index of this subgroup. In particular, if the index is 1, you have all of S_4 so every arrangement is reachable. The order of S_4 is 24 and there are 8 3-cycles. The subgroup must contain these 8 and the identity. The subgroup must contain these 8 members and the identity so its order must be at least 9.. Since the order must divide 24, it must be either 12 or 24 so the index must be 1 or 2. Furthermore(2314)(1423)=(4213)(3124)(1423)=(2143)(2314)(1342) =(3412)(3124)(1342)=(4132)so the order is at least 9+4=13 so the order is 24, the index is 1, and every arrangement is reachable.Have a tolerable existence. Eli Transformations of the square can be represented by the subgroup of S_4 (the >symmetric group on four letters) generate by 3-cycles. The question is, >what is the index of this subgroup. In particular, if the index is 1, you >have all of S_4 so every arrangement is reachable. The order of S_4 is 24 >and there are 8 3-cycles. The subgroup must contain these 8 and the >identity. The subgroup must contain these 8 members and the identity so >its order must be at least 9.. Since the order must divide 24, it must be >either 12 or 24 so the index must be 1 or 2. Furthermore>(2314)(1423)=(4213) This is a 3-cycle>(3124)(1423)=(2143)>(2314)(1342)=(3412)>(3124)(1342)= (4132)>so the order is at least 9+4=13 so the order is 24, the index is 1, and >every arrangement is reachable.Sorry, the order is 12. Its the alternating group A_4. Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israelUniversity of British ColumbiaVancouver, BC, Canada V6T 1Z2 (2314)(1423)=(4213)> This is a 3-cycle>>(3124)(1423)=(2143)>>(2314)(1342)=(3412)>>(3124)( 1342)=(4132)>>so the order is at least 9+4=13 so the order is 24, the index is 1, and>>every arrangement is reachable.> Sorry, the order is 12. Its the alternating group A_4.Yeah, I should have realized that. I guess I have an itchy trigger nger.Have a tolerable existence. Eli =Has anyone here used the book The Best Test Preparation for the GREin in Mathematics? Its published by the the Research and EducationAssociation.I was trying a few of the practice tests just go give myself an ideaof the test and feeling quite annoyed. They seem to ask a lot of veryobscure things that I never covered in any calculus/linearalgebra/abstract algebra/etc class Ive ever taken.Several reviews Ive seen gave the same opinion that I had of the book(not too great practice for the test itself).Whats the best book you would recommend to prepare for the test? =I have been using The Princeton Reviews GRE Math test book. Once again,it is a little harder than what is really on the test (from what I have beentold), but I think that it will serve as a good practice book. If you cando those problems, then the test should be easy. If I recall correctly, thetest consists of over 50% Calculus(Analysis) problems. Review Calc. andAnalysis!Lurch> Has anyone here used the book The Best Test Preparation for the GRE> in in Mathematics? Its published by the the Research and Education> Association.>> I was trying a few of the practice tests just go give myself an idea> of the test and feeling quite annoyed. They seem to ask a lot of very> obscure things that I never covered in any calculus/linear> algebra/abstract algebra/etc class Ive ever taken.>> Several reviews Ive seen gave the same opinion that I had of the book> (not too great practice for the test itself).>> Whats the best book you would recommend to prepare for the test? Has anyone here used the book The Best Test Preparation for the GRE> in in Mathematics? Its published by the the Research and Education> Association.I was trying a few of the practice tests just go give myself an idea> of the test and feeling quite annoyed. They seem to ask a lot of very> obscure things that I never covered in any calculus/linear> algebra/abstract algebra/etc class Ive ever taken.Several reviews Ive seen gave the same opinion that I had of the book> (not too great practice for the test itself).Whats the best book you would recommend to prepare for the test?I was very pleased with the book by the Princeton Review. Idsay that the practice tests and strategy gave me at leastanother 100 points on each section. It just really helpedto get a feeling for how fast I should expect to be moving.I still blew the timing in the math test, spending way toomuch time on some early questions that I thought just a*little* more calculation could help with. But the strategyhelped there too: I knew that guessing was a good strategyon the subject tests, if you could condently eliminate all but 3 or fewer choices. So I zipped through the last third of the test as fast as possible, eliminating a fewchoices on each question and then guessing. This strategygot me a 990. - Randy =i need a small result to prove something, and it seems so simple and idont know why i cant get itsup (xn + yn) <= sup xn + sup ynfor all real sequences xn and yn. i dont understand, this seems i need a small result to prove something, and it seems so simple and i> dont know why i cant get itsup (xn + yn) <= sup xn + sup ynfor all real sequences xn and yn. i dont understand, this seems so> xn so xa + ya <= sup xn + ya. Taking the supremum over a yields, sup (xn + yn) = sup (xa + ya) <= sup (sup xn + ya) = sup xn + sup ya = sup xn + sup yn.Have a tolerable existence. Eli =Type in half a cup in teaspoonsor sqrt(3) * sqrt(5) * sqrt(7)in Google.comPretty cool.Discovered it when typing in a phone number. Type in half a cup in teaspoons> or sqrt(3) * sqrt(5) * sqrt(7)in Google.com> Pretty cool.Nah. It doesnt do symbolic calculations ;-)Gib Type in half a cup in teaspoons> or sqrt(3) * sqrt(5) * sqrt(7)in Google.com> Pretty cool.Discovered it when typing in a phone number.Excellent. It appears to be a copy of the unix units utilityIt even has the geeks favorite unit: furlongs per fortnight:1 (furlong per fortnight) = 3.23383197 [Times] 10-25 megaParsecs per minuteGoodfind.Dale. > It even has the geeks favorite unit:>> furlongs per fortnight:>> 1 (furlong per fortnight) = 3.23383197 [Times] 10-25 megaParsecs per minute>> Goodfind.>> Dale.Useful when they have intergalactic horse racing. Could someone please give me a proof for distributive law of the cross>product:>>a x (b + c) = a x b + a x c>>But theres a catch! I am assuming the we have dened the cross>product as (|a||b|sinO)n, etc. Using the above proof (that is, taking>the above as true) THEN I will use the above truth to derive the>rectangular form of the cross product. So I need the above proved>without resorting to the rectangular form/defn of the cross product.>>Thanx in advance>Use the denition of the cross product: That is if v = q X pthen the ith component of v is:v_i = eps_ijk q_j p_kwhere eps_ijk is the totally antisymetric tensor. That is,eps_123 = eps_231 = eps_312 = 1eps_132 = eps_321 = eps_213 = -1and all others are zeroThe ith component of the cross product on the LHS of yourequation is:(a X (b + c))_i= eps_ijk (a_j) ((b + c)_k)= eps_ijk (a_j) (b_k + c_k)= ( eps_ijk (a_j) (b_k) ) + ( eps_ijk (a_j) (c_k) )= (a X b)_i + (a X c)_i<--> a X (b + c) = (a X b) + (a X c) hope that helps,adam =The idea was to derive the distributive law for the cross productassuming we dene the cross product as a x b = (|a||b|sinO)n, forvectors a, b, n, etc.The thing I am actually trying to do that many textbooks dont botherto do is to derive one denition from the other. You see, onetextbook says we dene the cross product as and then derives |axb| = |a||b|sinO and so we have the magnitude ofthe cross product. It then goes onto to explain why the cross productis perpendicular to these 2 vectors (e.g. (axb).b = 0, etc). BUT itdoes not explain how we DERIVE the need for the RIGHT-HAND RULE to getthe direction of n, and here is where I am stuck.Now the other way to do it, is to take the cross-product to be denedasa x b = (|a||b|sinO)n and then try to get it into form. Easy PROVIDED you accept that the cross-product isdistributive! But I wont just assume - I would like a proof!Perhaps you know such a proof?Thnx in advanceMB>Could someone please give me a proof for distributive law of the cross>product:>>a x (b + c) = a x b + a x c>>But theres a catch! I am assuming the we have dened the cross>product as (|a||b|sinO)n, etc. Using the above proof (that is, taking>the above as true) THEN I will use the above truth to derive the>rectangular form of the cross product. So I need the above proved>without resorting to the rectangular form/defn of the cross product.>>Thanx in advance>> Use the denition of the cross product: That is if v = q X p> then the ith component of v is:v_i = eps_ijk q_j p_kwhere eps_ijk is the totally antisymetric tensor. That is,eps_123 = eps_231 = eps_312 = 1> eps_132 = eps_321 = eps_213 = -1> and all others are zero> The ith component of the cross product on the LHS of your> equation is:(a X (b + c))_i= eps_ijk (a_j) ((b + c)_k)= eps_ijk (a_j) (b_k + c_k)= ( eps_ijk (a_j) (b_k) ) + ( eps_ijk (a_j) (c_k) )= (a X b)_i + (a X c)_i<--> a X (b + c) = (a X b) + (a X c) hope that helps,adam =It has been a long time since I have used a matrix, and I dontremember quite how to do it. I am not even sure that it is the rightapproach to solving this problem. Please read the problem, and then ifa matrix is the way to solve it and there is a web reference (I havesearched, but am confused) that will help, please point me there, andif there is a better way of going at this rather than a matrix, I aminterested in that too.Problem: Our company voted on 15 movies to screen for a Halloween lmfestival, one movie each day. Each employee voted on their top 5 picksand noted which day they will be able to attend. Their top pick isworth 7 points, second pick is worth 6 points, third pick is worth 5points, 4th=4 points, 5th=3 points. Any day they plan on attendingtheir votes count towards the tally on that day, and any day theyarent attending their votes dont count. We are going to screen 5movies (Monday-Friday) and the goal is to maximize the total pointsfor the week, with the assumption that if we do that then the mostpossible people will be satised.That may sound like a problem out of a textbook, but it is really whatwe are doing, and while most normal people would just show the top 5movies voted for (and not even bother weighting the scale nor breakingit down to who is there each day), well Im just not that normal. Ihave to make things complicated and desire to have the theoreticalmaximum happy points. When I realized my rst solution was notmaximized, it drove me to seek a more appropriate mathematical modelto solve the problem.Ill give just the top 7 movies to make it simpler:(A, B, C, D, E, F, G)Monday = (37 29 22 22 11 3 14)Tuesday = (45 29 27 21 17 14 26)Wednesday = (51 39 40 21 20 11 20)Thursday = (46 22 28 15 18 16 20)Friday = (29 19 12 9 7 6 10)My rst solution was to nd the largest number total (51 onWednesday for movie A) and then remove all other choices for Wednesdayand movie A and look for the next largest number (Movie B on Tuesday =29 points).Then I realized if I moved Movie A to Tuesday it would reduce thepoints by 6 but moving movie B to Wednesday increased it by 10 points,a net increase of 4 points. So thats where I stand, 144 points.Can anyone point me in the direction of solving this problem thecorrect way?Eric Wikman Problem: Our company voted on 15 movies to screen for a Halloween lm>festival, one movie each day. Each employee voted on their top 5 picks>and noted which day they will be able to attend. Their top pick is>worth 7 points, second pick is worth 6 points, third pick is worth 5>points, 4th=4 points, 5th=3 points. Any day they plan on attending>their votes count towards the tally on that day, and any day they>arent attending their votes dont count. We are going to screen 5>movies (Monday-Friday) and the goal is to maximize the total points>for the week, with the assumption that if we do that then the most>possible people will be satised.This is called an Assignment Problem, and there are standard algorithmsfor solving it. You can use linear programming: there are more specialized algorithms that are more efcient, but that shouldnt bea consideration here as your problem is not that big. The linear programmingformulation is as follows. You have variables x_{ij} for each movie iand each day j: x_{ij} = 1 in the solution means you show movie i on day j. Let c_{ij} be the number of points for movie i on day j.maximize sum_i sum_j c_{ij} x_{ij}subject to sum_i x_{ij} = 1 for each j (i.e. exactly one movie is shown on each day) sum_j x_{ij} <= 1 for each i(i.e. each movie is shown on at most one day)all x_{ij} >= 0The Integrality Theorem for network ow problems guarantees that in a basic solution (which is what standard linear programming softwarends) all variables will be 0 or 1.Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 Problem: Our company voted on 15 movies to screen for a Halloween lm>festival, one movie each day. Each employee voted on their top 5 picks>and noted which day they will be able to attend. Their top pick is>worth 7 points, second pick is worth 6 points, third pick is worth 5>points, 4th=4 points, 5th=3 points. Any day they plan on attending>their votes count towards the tally on that day, and any day they>arent attending their votes dont count. We are going to screen 5>movies (Monday-Friday) and the goal is to maximize the total points>for the week, with the assumption that if we do that then the most>possible people will be satised.>>That may sound like a problem out of a textbook, but it is really what>we are doing, and while most normal people would just show the top 5>movies voted for (and not even bother weighting the scale nor breaking>it down to who is there each day), well Im just not that normal. I>have to make things complicated and desire to have the theoretical>maximum happy points. When I realized my rst solution was not>maximized, it drove me to seek a more appropriate mathematical model>to solve the problem.>>Ill give just the top 7 movies to make it simpler:>(A, B, C, D, E, F, G)>Monday = (37 29 22 22 11 3 14)>Tuesday = (45 29 27 21 17 14 26)>Wednesday = (51 39 40 21 20 11 20)>Thursday = (46 22 28 15 18 16 20)>Friday = (29 19 12 9 7 6 10)Sounds like a combinatorial optimization problem, which can sometimesbe approximated by a linear programming problem. You have an objectivefunction (total score for the festival?) which appears to be linear,which you are trying to maximize, you have some constraints (eachmovie shown once, only one movie per day).You have 75 variables (one for movie A on Monday, one for movie A onTuesday, ..., one for movie B on Monday,.... ), each of which can be 0or 1. Set up as a linear program, you would relax the requirement sothat the variables were required to be between 0 and 1. Then you roundat the end.Excel has a built in solver which, correctly set up, can solve someoptimization problems. I know it does LPs, and it may do integerproblems. - Randy =i want know why number 1 does not contain in the prime number.if 1 in prime, what trouble is happen?? i want know why number 1 does not contain in the prime number.if 1 in prime, what trouble is happen??We lose the Fundamental Theorem of Arithmetic: that every integer hasa unique prime factorization except for the order of the factors. If 1is not prime then, for example, we can factor 6 as 2*3. If we DO count1 as a prime then 6 can be factored in an innite number of ways,such as 2*3 = 1*2*3 = 1*1*2*3 and so on. It just makes things moretidy.Darren =from math2050@yahoo.co.kr:>>i want know why number 1 does not contain in the prime number.>>if 1 in prime, what trouble is happen??>The factors of 1 are only 1.The ONLY factor of 1 is 1. A prime number has only the factors 1 and itself. A composite number hasfactors of 1, itself, and at least one other prime number. Since 1 has only 1 as a factor, it is not prime and not composite. To say that one has 1 and 1 as its factors is not productive, because anynumber may be multiplied by 1 any number of times and will still produce 1 as aresult. We do not do this when we are listing or factoring a number to showits prime factors. G C i want know why number 1 does not contain in the prime number.if 1 in prime, what trouble is happen??The trouble is that, if 1 is a prime, then positive integers cant be factored into primes uniquely because you can include any number one 1s in the list of factors. For example, if 1 is not a prime, then the only way to write 4 as a product of primes is 2*2. However, if 1 is prime then 4=2*2=1*2*2=1*1*2*2=1*1*1*2*2=. . . Have a tolerable existence. Eli-- i want know why number 1 does not contain in the prime number.if 1 in prime, what trouble is happen??Fundamental theorem of arithmetic (unique factorization) fails to hold, forone.--Bill Barksdale =Now maybe some of you understand the test.The Universe periodically tests species. Humanity has a version ofsentience, so She tested you in mathematics.Remember? Mathematics is the universal language.I told you the Universe has a sense of humor.Were having fun. Please continue.James Harris =I was going to not post (just read, sheepishly), butit hasnt been resolved about TheRealHSJ@MSN.com;was it always him, or does he have to personalities, ordid he beat the impostor out of it? (Ferrys posting reminds meof that pentacostal wingnut that Rumsfeld just appointed;what they dont note is thatthe military chaplaincy, even the Catholic ones,are largely converted to that style of preaching,Holy Rollers or Amy Semple McPherson e.g.) oh, I see;the real HSJ would never make a blatant suicide-note header;would it?> Now maybe some of you understand the test.--les ducs dEnron! I was going to not post (just read, sheepishly), but> it hasnt been resolved about TheRealHSJ@MSN.com;> was it always him, or does he have to personalities, or> did he beat the impostor out of it?> (Ferrys posting reminds me> of that pentacostal wingnut that Rumsfeld just appointed;> what they dont note is that> the military chaplaincy, even the Catholic ones,> are largely converted to that style of preaching,> Holy Rollers or Amy Semple McPherson e.g.)And you never ask questionsWith God on your sideGib Now maybe some of you understand the test.Very few, no doubt.> The Universe periodically tests species. Humanity has a version of> sentience, so She tested you in mathematics.Remember? Mathematics is the universal language.I told you the Universe has a sense of humor.Were having fun. Please continue.I had another dream last night. It may have been inspired bythe promo I saw for the *trailer* of LotR 3, but Frodo could bea symbol of you.I was Sam, standing with Frodo at the Crack of Doom. We wereboth just standing there, sort of waiting around, confused. Iwas thinking, well, this is the part where he takes Ring andcasts it into the re, but then decides to wield it himself,but Gollum bites off his nger. None of this happened though.We were just standing there. Wheres the Ring, Frodo? I thoughtyou had it, Sam -- youre the best man. What? Oh no, we didntleave it back in the Shire, did we?So we walked out onto the slope of Mt. Doom. The entire base ofthe mountain was swirling with orcs. It was beautiful, actually,as if we were the vortex. We looked up to see Gwaihir (king ofthe eagles), coming to our rescue, but as he swooped toward ushe turned into an F-16. Wind. Noise. When we looked aroundagain, the swirling mass of orcs were Islamic pilgrims. We werein Mecca, standing on the very axis about which the Muslim worldrotates.I thought Id better leave. I got separated from Frodo. I wanderedabout, and ended up studying the Koran with a teacher of some kind(white robes). I was bored. So he taught me to dance instead.Iss tay la na bude lay la . . . -- some sort of dancing and singing.I felt like I was getting into the spirit of the place.When I went outside, Frodo was up on a soapbox. But now he lookedlike Uncle Sam meets G. I. Joe. He was haranguing the crowd abouthow they lived in a dictatorship, that democracy was the only way toprosperity and human dignity, that women were being oppressed, andI tried to get to him to make him stop (especially about the Allahpart), but I couldnt. Then I woke up. Now maybe some of you understand the test.>> The Universe periodically tests species. Humanity has a version of> sentience, so She tested you in mathematics.>> Remember? Mathematics is the universal language.>> I told you the Universe has a sense of humor.>> Were having fun. Please continue.>> James HarrisLets see if I get this straight. You, James Harris, are the Universe.We, the readers of this newsgroup, are the species under test. Is thatright? (Please seek professional help.)--There are two things you must never attempt to prove: the unproveable --and the obvious.--Democracy: The triumph of popularity over principle.--http://www.crbond.com Now maybe some of you understand the test.>>The Universe periodically tests species. Humanity has a version of>sentience, so She tested you in mathematics.>>Remember? Mathematics is the universal language.>>I told you the Universe has a sense of humor.>>Were having fun. Please continue.If you dont like it when people say youre crazy then stopsaying things that make you sound like a raving lunatic.>James Harris************************David C. Ullrich Now maybe some of you understand the test.The Universe periodically tests species. Humanity has a version of> sentience, so She tested you in mathematics.Remember? Mathematics is the universal language.And you are a broken record, with bits of mathematics mixed together incorrectly, and forever repeating. Now maybe some of you understand the test.>> The Universe periodically tests species. Humanity has a version of> sentience, so She tested you in mathematics.>> Remember? Mathematics is the universal language.>> I told you the Universe has a sense of humor.>> Were having fun. Please continue.> James HarrisAnd the point of this is....? >>Now maybe some of you understand the test.>>The Universe periodically tests species. Humanity has a version of>>sentience, so She tested you in mathematics.>>Remember? Mathematics is the universal language.>>I told you the Universe has a sense of humor.>>Were having fun. Please continue.>>James Harris> And the point of this is....?To keep attention focussed on JSH?Gib > > So, lets not be complimentary. However:> Dr. David Ullrich has argued that at least one is a head and at> least one is a tail are _the same_ statement. What does that mean to> you?Blimey! Did he really?What he actually said was that surely, even I, Eldon Moritz, is notdumb enough to think changing those two words makes a difference.Is he dumb enough? Right now, hes non committal. With this questionhe goes into the obfuscation mode rather easily.> To me it means that with a ip of HH, we had, Two coins were ipped> and at least one is a head. What are the chances for two heads? and> with TT we had Two coins were ipped and at least one is a tail.> What are the chances for two tails?> With HT, or TH, either statement was true, was equally likely, and one> was made.> Mathematically speaking they would be the same statement, and the same> question. They would have the same mathematics and the same answer.> When they are the same, they would have correct answer 1/2.> To have answer other than 1/2, they would have different answers.Sorry, I cant be complimentary about your clarity.> I cant make head nor tail of your arhuments :-(Suppose that we ipped umpteen thousand times, we should getumpteen/4 HH and umpteen/r TT. So we would have the heads statementumpteen/4 and the tails statement umpteen/4.Then there are u/4 HTs and u/4 THs. Each one of these ips was recreating a rst time event. On a rst time event, with HT, or TH,the generator of the statement would not know whether to favor heads,or tails. Therefore there should be another u/4 for the heads andanother u/4 for the tails for the HTs and THs.If you altered all the HTs and THs to say heads every time, or tailsevery time then the answer to the favored color would be 1/3, howeverthe unfavored color would only have the double, therefore when oneside answers 1/3, the other side answers 1. The only place where theywould both be equal is at zero prejudice, or 1/2.Dr. Ullrich cant make up his mind whether he wishes to be wrong now,or six months ago. Thats a dilemma:~)Eldon If you altered all the HTs and THs to say heads every time, or tails> every timeAs before, I still cant make head nor tail of your arguments.-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.htmlNeedless to say, I had the last laugh. Alan Partridge, _Bouncing Back_ (14 times) > Dr. David Ullrich has argued that at least one is a head and at>> least one is a tail are _the same_ statement. What does that mean to>> you?>>Blimey! Did he really?Of course not.I beg your pardon, Doctor Ullrich. Its in the archives, they can lookit up.I dug the following out of the archives:##################3###############this>> is 1/3. B. Two coins were ipped. At least one is a head. What are the>> chances for two heads? Many mathematicians do not understand thatthis>> is 1/2.You switched from tails to heads here. Presumably even _you_ dontthink that that makes a difference; presumably you would also sayA. Two coins were ipped. Given that there is at least one tail,what are the chances for two tails? Many laymen do not understand that this is 1/3. B. Two coins were ipped. At least one is a tail. What are thechances for two tails? Many mathematicians do not understand that thisis 1/2.#################################I had dened A. and B. You redened them as A and B becausepresumably even me doesnt think that makes a difference. You wereright, I dont, but you were also arguing that at least one is atail and at least one is a head are, mathematically speaking, thesame statement.We agreed that they are, we agree that they are, my argument stands,and your apology is accepted:)Eldon>> To me it means that with a ip of HH, we had, Two coins were ipped>> and at least one is a head. What are the chances for two heads? and>> with TT we had Two coins were ipped and at least one is a tail.>> What are the chances for two tails?> With HT, or TH, either statement was true, was equally likely, and one>> was made.> Mathematically speaking they would be the same statement, and the same>> question. They would have the same mathematics and the same answer.> When they are the same, they would have correct answer 1/2.>> To have answer other than 1/2, they would have different answers.>>Sorry, I cant be complimentary about your clarity.>I cant make head nor tail of your arhuments :-(> My clarity is suspect, but my argument is correct. When two coins areipped and they land HT, or TH, then either statement is true, eitherthe heads or the tails statement. Either could be made and eithershould have the same answer. When they do, its a half. You could skewthe odds toward heads and away from tails, or vise versa. Have extremeprejudice toward heads; always make the heads statement when itstrue, only make the tails statement when the heads statement isnttrue, then the probability for HH is 1/3 on the heads statement andthe probability for two TT with the tails statement is 1.(it couldonly be made when the heads statement wasnt possible, that would beTT)To answer one question 1/3, you must answer the other question 1. Whentheyre the same, when the are equally likely at HT and TH, then theyboth answer 1/2. Thats about as clear as I can make it.Eldon> ************************David C. Ullrich > Dr. David Ullrich has argued that at least one is a head and at> least one is a tail are _the same_ statement. What does that mean to> you?>>Blimey! Did he really? Of course not.>I beg your pardon, Doctor Ullrich. Its in the archives, they can look>it up.>>I dug the following out of the archives:Good for you. Youd have a better point, and look a little lessridiculous, if you supported your assertion that I said thosetwo statements were the same statement with something inthe archives that actually shows me saying that! I _dont_say that in the quote below.>##################3###############>Counter-intuitive mathematical results>> A. Two coins were ipped. Given that there is at least one tail,>what> are the chances for two tails? Many laymen do not understand that>this> is 1/3.> B. Two coins were ipped. At least one is a head. What are the> chances for two heads? Many mathematicians do not understand that>this> is 1/2.>>You switched from tails to heads here. Presumably even _you_ dont>think that that makes a difference; presumably you would also say>>A. Two coins were ipped. Given that there is at least one tail,>what are the chances for two tails? Many laymen do not understand >that this is 1/3.>B. Two coins were ipped. At least one is a tail. What are the>chances for two tails? Many mathematicians do not understand that this>is 1/2.>#################################Yes, I said the above. And nowhere above does it show me sayingthat at least one is a head and at least one is a tail are thesame statement.>I had dened A. and B. You redened them as A and B because>presumably even me doesnt think that makes a difference. You were>right, I dont, but you were also arguing that at least one is a>tail and at least one is a head are, mathematically speaking, the>same statement.I was arguing that? Only in your imagination (or to be fair, yourloose/imprecise interpretation of what I said.)(HINT: Saying that it doesnt make any difference whether we talkabout one problem or another problem says that if we know theanswer to one we then know the answer to the other. It doesnot say that the _statements_ in the problems are the _same_.Duh.)>We agreed that they are, we agree that they are, my argument stands,>and your apology is accepted:)Youre a funny guy, we all agree on that.>Eldon>> To me it means that with a ip of HH, we had, Two coins were ipped> and at least one is a head. What are the chances for two heads? and> with TT we had Two coins were ipped and at least one is a tail.> What are the chances for two tails?> With HT, or TH, either statement was true, was equally likely, and one> was made.> Mathematically speaking they would be the same statement, and the same> question. They would have the same mathematics and the same answer.> When they are the same, they would have correct answer 1/2.> To have answer other than 1/2, they would have different answers.>>Sorry, I cant be complimentary about your clarity.>>I cant make head nor tail of your arhuments :-(>>My clarity is suspect, but my argument is correct. When two coins are>ipped and they land HT, or TH, then either statement is true, either>the heads or the tails statement. Either could be made and either>should have the same answer. When they do, its a half. You could skew>the odds toward heads and away from tails, or vise versa. Have extreme>prejudice toward heads; always make the heads statement when its>true, only make the tails statement when the heads statement isnt>true, then the probability for HH is 1/3 on the heads statement and>the probability for two TT with the tails statement is 1.(it could>only be made when the heads statement wasnt possible, that would be>TT)>To answer one question 1/3, you must answer the other question 1. When>theyre the same, when the are equally likely at HT and TH, then they>both answer 1/2. Thats about as clear as I can make it.>>Eldon> ************************ David C. Ullrich************************David C. Ullrich > > Dr. David Ullrich has argued that at least one is a head and at> least one is a tail are _the same_ statement. What does that mean to> you?>>Blimey! Did he really?> Of course not.>I beg your pardon, Doctor Ullrich. Its in the archives, they can look>it up.>>I dug the following out of the archives:Good for you. Youd have a better point, and look a little less> ridiculous, if you supported your assertion that I said those> two statements were the same statement with something in> the archives that actually shows me saying that! I _dont_> say that in the quote below.>##################3###############>Counter-intuitive mathematical results>> A. Two coins were ipped. Given that there is at least one tail,> what> are the chances for two tails? Many laymen do not understand that> this> is 1/3.> B. Two coins were ipped. At least one is a head. What are the> chances for two heads? Many mathematicians do not understand that> this> is 1/2.>>You switched from tails to heads here. Presumably even _you_ dont>think that that makes a difference; presumably you would also say>>A. Two coins were ipped. Given that there is at least one tail,>what are the chances for two tails? Many laymen do not understand >that this is 1/3.>B. Two coins were ipped. At least one is a tail. What are the>chances for two tails? Many mathematicians do not understand that this>is 1/2.>#################################Yes, I said the above. And nowhere above does it show me saying> that at least one is a head and at least one is a tail are the> same statement.>I had dened A. and B. You redened them as A and B because>presumably even me doesnt think that makes a difference. You were>right, I dont, but you were also arguing that at least one is a>tail and at least one is a head are, mathematically speaking, the>same statement.> We have statement B:Two coins were ipped and at least one is a head.We have statement B:Two coins were ipped and at least one is atail.What do you argue? What do you say now?I say that mathematically speaking, B and B are the same statement.That changing from heads to tails doesnt change the statement, thequestion, or the answer.What do you say now? Do you now say that changing from heads to tailschanges the question?Changing from heads to tails either alters the question, or itdoesnt. What does Doctor Ullrich say?Eldon ipped and at least one is a head.> We have statement B:Two coins were ipped and at least one is a> tail.>> What do you argue? What do you say now?> I say that mathematically speaking, B and B are the same statement.> That changing from heads to tails doesnt change the statement, the> question, or the answer.>> What do you say now? Do you now say that changing from heads to tails> changes the question?> Changing from heads to tails either alters the question, or it> doesnt. What does Doctor Ullrich say?>> EldonI cant speak for Dr. Ullrich, but I can ask if you see any distinction between two phrases which are identical, and twophrases which are equivalent? To most analysts, equivalence holds within limits, identity does not.--There are two things you must never attempt to prove: the unprovable -- and the obvious.--Democracy: The triumph of popularity over principle.--http://www.crbond.com statement B:Two coins were ipped and at least one is a head.>> We have statement B:Two coins were ipped and at least one is a>> tail.>> What do you argue? What do you say now?>> I say that mathematically speaking, B and B are the same statement.It depends on what question youre going to ask. Youve taken half theproblem statement but havent said whether youre changing the otherhalf.If you make a swap of heads and tails THROUGHOUT THE ENTIRE QUESTION,then they are equivalent questions.To whit: With a weighted coin which falls on heads with probability0.75, what is the probability of three heads in a row?Same question as: With a weighted coin which falls on tails withprobability 0.75, what is the probability of three tails in a row?But that does not mean that a weighted coin which falls on tails withprobability 0.75 is identical to a weighted coin which falls onheads with probability 0.75. Here is a different question:With a weighted coin which falls on tails with probability 0.75, whatis the probability of three heads in a row?See how that works? Change the labelling in the whole question: samequestion. Change the labelling in half the question, might be the sameor might be different. - Randy statement B:Two coins were ipped and at least one is a head.>> We have statement B:Two coins were ipped and at least one is a>> tail.>> What do you argue? What do you say now?>> I say that mathematically speaking, B and B are the same statement.It depends on what question youre going to ask. Youve taken half the> problem statement but havent said whether youre changing the other> half.If you make a swap of heads and tails THROUGHOUT THE ENTIRE QUESTION,> then they are equivalent questions.To whit: With a weighted coin which falls on heads with probability> 0.75, what is the probability of three heads in a row?Same question as: With a weighted coin which falls on tails with> probability 0.75, what is the probability of three tails in a row?But that does not mean that a weighted coin which falls on tails with> probability 0.75 is identical to a weighted coin which falls on> heads with probability 0.75. Here is a different question:With a weighted coin which falls on tails with probability 0.75, what> is the probability of three heads in a row?See how that works? Change the labelling in the whole question: same> question. Change the labelling in half the question, might be the same> or might be different. - RandyWe have coins of equal density. Heads and tails are equally likely. Iwas trying to get Ullrichs opinion nailed down. He seems to bewafing.You and I seem to agree.When we shipped HH and said, Two coins were ipped and at least oneis a head. What are the chances for two heads? or we ipped TT, andsaid Two coins were ipped and at least one is a tail. What are thechances for two tails? We would have the same question with the sameanswer.Likewise, with a HT, or a TH ip, either statement would be true.Either question would have the same answer. For one of them to haveanswer other than 1/2, they would have to have different answers.Eldon We have statement B:Two coins were ipped and at least one is a head.>> We have statement B:Two coins were ipped and at least one is a>> tail.>> What do you argue? What do you say now?>> I say that mathematically speaking, B and B are the same statement.> It depends on what question youre going to ask. Youve taken half the> problem statement but havent said whether youre changing the other> half.> If you make a swap of heads and tails THROUGHOUT THE ENTIRE QUESTION,> then they are equivalent questions.> To whit: With a weighted coin which falls on heads with probability> 0.75, what is the probability of three heads in a row?> Same question as: With a weighted coin which falls on tails with> probability 0.75, what is the probability of three tails in a row?> But that does not mean that a weighted coin which falls on tails with> probability 0.75 is identical to a weighted coin which falls on> heads with probability 0.75. Here is a different question:> With a weighted coin which falls on tails with probability 0.75, what> is the probability of three heads in a row?> See how that works? Change the labelling in the whole question: same> question. Change the labelling in half the question, might be the same> or might be different.> - RandyWe have coins of equal density. Heads and tails are equally likely. I> was trying to get Ullrichs opinion nailed down.No, he is not. You are misinterpreting his quite clear statement.He is trying to say your misinterpretation is not his originalstatement. The difference is quite clear when the two arelaid side by side, as you did in your quote.You and I seem to agree.I mostly avoid your threads because your silly obsessionwith this particular probability problem and yourpeculiar reading of it. So no, I would not say we agree.> When we ipped HH and said, Two coins were ipped and at least one> is a head. What are the chances for two heads? or we ipped TT, and> said Two coins were ipped and at least one is a tail. What are the> chances for two tails? We would have the same question with the same> answer.No. The question does not include what was ipped. Take thestatements in quotes, i.e.Two coins were ipped and at least one is a head. What are the chances for two heads?andTwo coins were ipped and at least one is a tail. What are thechances for two tails? And I will say these are the same question given a faircoin. Youve just relabelled heads and tails.When you add that there is a particular outcome given, itssilly to ask about probability since theres only onepoint in the sample space. The probability is 1 in bothof those cases.> Likewise, with a HT, or a TH ip, either statement would be true.Huh? The statement includes a question: What are thechances for two heads (tails)? How can that questionbe true?> Either question would have the same answer. For one of them to have> answer other than 1/2, they would have to have different answers.No, they have the same answer of 1/3.Case 1: I tell you two coins were ipped and one of thecoins is a head. Therefore you know that I have eitherHH, TH, or HT with equal probability. I ask you what isthe probability that I got HH? The answer is 1/3.Case 2: I tell you two coins were ipped and one of thecoins is a head. Therefore you know that I have eitherTT, HT, or TH with equal probability. I ask you what isthe probability that I got TT? The answer is 1/3.You will see that in exchanging H and T in thetwo paragraphs throughout, I have not changed themeaning or the interpretation. There is nothing likea requirement that the probability be 1/2. Your nalstatement is coming from somewhere outside of probabilitytheory. - Randy were ipped and at least one is a head.>> We have statement B:Two coins were ipped and at least one is a>> tail.> What do you argue? What do you say now?>> I say that mathematically speaking, B and B are the same statement.> It depends on what question youre going to ask. Youve taken half the> problem statement but havent said whether youre changing the other> half.> If you make a swap of heads and tails THROUGHOUT THE ENTIRE QUESTION,> then they are equivalent questions.> To whit: With a weighted coin which falls on heads with probability> 0.75, what is the probability of three heads in a row?> Same question as: With a weighted coin which falls on tails with> probability 0.75, what is the probability of three tails in a row?> But that does not mean that a weighted coin which falls on tails with> probability 0.75 is identical to a weighted coin which falls on> heads with probability 0.75. Here is a different question:> With a weighted coin which falls on tails with probability 0.75, what> is the probability of three heads in a row?> See how that works? Change the labelling in the whole question: same> question. Change the labelling in half the question, might be the same> or might be different.> - Randy> We have coins of equal density. Heads and tails are equally likely. I> was trying to get Ullrichs opinion nailed down. No, he is not. You are misinterpreting his quite clear statement.> He is trying to say your misinterpretation is not his original> statement. The difference is quite clear when the two are> laid side by side, as you did in your quote.>He chastised me for thinking that changing from heads to tails wouldchange that question. I didnt think it would and he didnt either.Now he says he wasnt arguing that it wouldnt.. > You and I seem to agree.I mostly avoid your threads because your silly obsession> with this particular probability problem and your> peculiar reading of it. So no, I would not say we agree.>We agree that changing from heads to tails does not alter thequestion, or the answer. Or we dont agree? I say that it doesnt.Surely you agree with that? > When we ipped HH and said, Two coins were ipped and at least one> is a head. What are the chances for two heads? or we ipped TT, and> said Two coins were ipped and at least one is a tail. What are the> chances for two tails? We would have the same question with the same> answer.No. The question does not include what was ipped. Take the> statements in quotes, i.e.Two coins were ipped. It says that right in the question. WEREFLIPPED, past tense. Were talking about a historical event. All weknow about the event is what we read in the statement.Two coins were ipped and at least one is a head. What > are the chances for two heads?andTwo coins were ipped and at least one is a tail. What are the> chances for two tails? And I will say these are the same question given a fair> coin. Youve just relabelled heads and tails.>When they landed HH the rst statement was true, when they landed TT,the second statement was true. At HT, or TH, either statement wouldhave been true.Consider the second statement. We know that the coins landed TT, orTH, or HT. Suppose that they landed TH. The other statement would havebeen true. If it had been made, would we have had a differentquestion? > When you add that there is a particular outcome given, its> silly to ask about probability since theres only one> point in the sample space. The probability is 1 in both> of those cases.> This is a probability question. The coins were ipped once. We can doprobability because we can re iterate the ip, umpteen thousands oftimes. The tricky part is that we are re iterating a rst time ip.We ip umpteen thousand times and each one was a rst time ip.With HH, the heads statement was made, with TT, the tails statementwas made, and with HT, or TH, one, or the other. Either would havebeen true, and would have been the same statement. OR, changing thecolor would have changed the statement.> Likewise, with a HT, or a TH ip, either statement would be true.Huh? The statement includes a question: What are the> chances for two heads (tails)? How can that question> be true?> Thats the point. Does changing from heads to tails alter thequestion.> Either question would have the same answer. For one of them to have> answer other than 1/2, they would have to have different answers.No, they have the same answer of 1/3.>Thats why I have this strange obsession. There are always qualiedpeople like you who will argue with me, and dont seem to want tounderstand my argument. > Case 1: I tell you two coins were ipped and one of the> coins is a head. Therefore you know that I have either> HH, TH, or HT with equal probability. I ask you what is> the probability that I got HH? The answer is 1/3.> I know that they landed HH, or HT, or TH. With HH, you made the headsstatement with probability one, but you made the tails statement withprobability 1/2.There are now three possible outcomes. They are no longer equallylikely outcomes.> Case 2: I tell you two coins were ipped and one of the> coins is a head. Therefore you know that I have either> TT, HT, or TH with equal probability. I ask you what is> the probability that I got TT? The answer is 1/3.>I know that you have TT, HT, or TH. They are no longer equallyprobably. Try it. You cant do it.Flip the coins but dont look. You cant make either statement, priorto inspection. After inspection you can make one statement, or theother. With HH, you can only make the heads statement. With TT, youcan only make the tails statement.With HT, or TH, you can make one, or the other, but not both. If youmake both, then I know that the probability is one that the two coinsare different. The four are equally probable, prior to inspection.After inspection, you can only make one statement, or the other. Afterthe statement, the three that are left are not equally probable. > You will see that in exchanging H and T in the> two paragraphs throughout, I have not changed the> meaning or the interpretation. There is nothing like> a requirement that the probability be 1/2. Your nal> statement is coming from somewhere outside of probability> theory.You ipped the coins and got the answer wrong. Thats what keeps meobsessed. My reading of the question is strange? My reading may bestrange, but you get the wrong answer, and you ipped the coins.Eldon - Randy =I am continuing, in a way, the thread FUNctions/Continued-FractionPuzzle, but not crossposting it to rec.puzzles this time.(For the focus is now not the original puzzle, but something moregeneral.)(What I have to add is below copy/pasted relevant parts of theprevious thread.)>>...>>...>>For all real x > 1, and for some function of x, y(x);>where each y is a real, y =y(x), based on x:>>it is so that:>>f([x; x^2, x^3, x^4,...,x^m]) >[y; y^2, y^3, y^4,...,y^m],>>for EVERY positive integer m;>>where:>>[x; x^2, x^3, x^4,...,x^m] is the continued-fraction>> 1>x + ------------------ ;> 1> x^2 + --------------> 1> x^3 + ---------> ....> + 1/x^m>>and [y; y^2, y^3, y^4,...,y^m] is also a continued-fraction(obviously);>>and [x; x^2, x^3, x^4,...,x^m] converges to X;>>and f(w) is a real -> real function, such that>>f(X) exists and is nite nonzero.>So, what are the possible f(w)s, given all of the conditionsabove??> First, by the way, f(X) is the (1st) derivative of f(w) at w =X, in>> case this is not obvious. I should mention that f can equate to an innite number offunctions>> if it need not be analytic. If it need by analytic, however,there are>> a nite number of possible functions that can equal f(w).>> (So,find the set of analytic f(w)s.)>>... ....>> ...the solution: I get that the only possible analytic f is: f(w) = w. Proof:> limit{m -> oo} (x/y)^(2m-1) = 1. So, x must = y. And, consequently, f(w) must = w.> * earlier result at:>> rnum=4&prev>I highly suspect my PROOF is far from the simplest.>Is there a PROOF which is any simpler, even trivial?>>(Perhaps my result itself, that f(w) = w is the ONLY analytic>function, is wrong.)>I believe that the result above can be generalized.Let g_k(x) be a family of real-> real functions, wherelimit{k->oo} g_k(x)/g_k(y) = 1ONLY if x = y, but the limit exists in any case,and where g(x) > 1 and is dened for all x in a given domain D.f is as above in the copied message (lots of conditions placed uponit).And g and f are so that, for all x in D, the continued fraction[g_1(x); g_2(x), g_3(x), g_4(x),..., g_m(x)]converges to X(x).And, analogous to above,the derivative of f(w) exists at all real w (just to be on the safeside),and is always nite and nonzero.Now, y(x) = y is a real-> real function such that: f([g_1(x); g_2(x), g_3(x), g_4(x),..., g_m(x)]) =[g_1(y); g_2(y), g_3(y), g_4(y),..., g_m(y)]for ALL positive integers m,and f and g are such that y(x) is in D for all x in D.(And did I mention that D contains an interval of positive length?)So, if f is analytic (so that f(w) is determined completely by itsevaluation within some possibly-nite domain for w), then I amguessing that it *must* be so thatf(w) = w.Because...limit{m -> oo} g_m(x) g_{m-1}(x)/(g_m(y) g_{m-1}(y)) = 1.And sinceg_m() is nonzero and nite,and g_m(x)/g_m(y) is not 1 if x is not y(nor is ever -1 since g is positive),then x = y, and then again f(w) = w.(I MUSt have missed something here, most likely a condition, if Isimply did = I have recently nished teaching myself basic group/ring/eldtheory using I.N. Hersteins Abstract Algebra. I am seeking thename/publisher/possibly ISBN of a good textbook of Galois theory. Itshould be one which lends itself well to being self-taught; and itshould be well steeped in theory (I like textbooks where a givensection gives the basics of something but the problems proceed toexpound upon that thing in great detail with numerous otherresults...) Money is not an issue since I consider this a toppriority investment however I lack access to a university bookstoreand so it would be good if the textbook can be ordered and shipped via SamP.S. Links to online tutorials are also good, although they do notseem to exist for Galois theory, or if they do they are rare and wellhidden... =Not sure if it is still in print, consider Algebraic Extensions of Fields by Paul J. McCarthy. = I have recently nished teaching myself basic group/ring/eld> theory using I.N. Hersteins Abstract Algebra. I am seeking the> name/publisher/possibly ISBN of a good textbook of Galois theory. It> should be one which lends itself well to being self-taught; and it> should be well steeped in theory (I like textbooks where a given> section gives the basics of something but the problems proceed to> expound upon that thing in great detail with numerous other> results...) Money is not an issue since I consider this a top> priority investment however I lack access to a university bookstore> and so it would be good if the textbook can be ordered and shipped viaOthers have suggested Ian Stewarts book, and I agree with them. I just wantto inform you that the most well steeped in theory of all textbooks on Galoistheory is Harold M. Edwards book Galois theory.Jose Carlos Santos P.S. Links to online tutorials are also good, although they do not> seem to exist for Galois theory, or if they do they are rare and well> hidden...http://www.maths.tcd.ie/~dwilkins/Courses/311/ has good online noteson Galois Theory. = I have recently nished teaching myself basic group/ring/eld> theory using I.N. Hersteins Abstract Algebra. I am seeking the> name/publisher/possibly ISBN of a good textbook of Galois theory. It> should be one which lends itself well to being self-taught; and it> should be well steeped in theory (I like textbooks where a given> section gives the basics of something but the problems proceed to> expound upon that thing in great detail with numerous other> results...) Money is not an issue since I consider this a top> priority investment however I lack access to a university bookstore> and so it would be good if the textbook can be ordered and shipped via> SamP.S. Links to online tutorials are also good, although they do not> seem to exist for Galois theory, or if they do they are rare and well> hidden...My experience (in the U.S.) is that one can often examine a book byrequesting an interlibrary loan. And if you want online materials,try a search engine such as www.alltheweb.com with a compound searchterm such asgalois lecture notesand you are sure tofind something.David Ames I have recently nished teaching myself basic group/ring/eld> theory using I.N. Hersteins Abstract Algebra. I am seeking the> name/publisher/possibly ISBN of a good textbook of Galois theory. Ian Stewart, Galois Theory, published by Chapman and Hall.-- I have recently nished teaching myself basic group/ring/eld> theory using I.N. Hersteins Abstract Algebra. I am seeking the> name/publisher/possibly ISBN of a good textbook of Galois theory.> Ian Stewart, Galois Theory, published by Chapman and Hall.Many ciphers use calculations in GF(2^8). I would like to understand thosecalculations better. Would this book be a total overkill for that matter, orwould it be *the* book to buy?