mm-1016 === Subject: Fermatproof of FLT Stay tune for presentation of Fermats proof of FLT No beating the bush around! As Euler miss to find a elementary proof of Pells Equation so it happened that another great mathematicians miss to find the Fermats proof of FLT. By tomorow morning(may be tonight)will be posted. george ghiata === Subject: Re: Fermatproof of FLT by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBL3uDj24024; >Stay tune for presentation of Fermats proof of FLT >No beating the bush around! >As Euler miss to find a elementary proof of Pells Equation so it >happened that another great mathematicians miss to find the >Fermats proof of FLT. >By tomorow morning(may be tonight)will be posted. >george ghiata I cant wait until tomorrow morning, please post tonight. Joseph A. === Subject: Re: Fermatproof of FLT by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBLFfMi18716; Hi Joseph, I am sorry, I want to let all of you that I was very late back home and I just wake -up .I do not want to let you down but when I recover I will sit down and write the message and post it right the way. That will be very soon. P.S.So there is left a chance for somebodyelse too. george ghiata >>Stay tune for presentation of Fermats proof of FLT >>No beating the bush around! >>As Euler miss to find a elementary proof of Pells Equation so it >>happened that another great mathematicians miss to find the >>Fermats proof of FLT. >>By tomorow morning(may be tonight)will be posted. >>george ghiata >I cant wait until tomorrow morning, please post tonight. >Joseph A. === Subject: Re: And then there was George ... by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBKLliD25147; Well.from your point of you the odds are against me. I recognise that. george >>Stay tune for presentation of Fermats proof of FLT >>No beating the bush around! >>As Euler miss to find a elementary proof of Pells Equation so it >>happened that another great mathematicians miss to find the >>Fermats proof of FLT. >>By tomorow morning(may be tonight)will be posted. >>george ghiata >George, >I was wondering if you had any notions regarding 0.999...? >- MO === Subject: Re: Why do two negatives equal a positive? > using the field axioms is perfect except for a major ßaw which > (atleast in my eyes) has rendered it useless. we are trying to prove > here that when a negetive and a positive integer is multiplied the > result is positive. No, we are trying to show that when two negative integers are multiplied the result is positive. Multiplying a positive and a negative will give you a negative... > why? but in your solution, you have used the same > property in the third line without proving it first. Here are the second and third lines, if I understand you correctly: So where exactly has Matt used the same property without proof? (Answer: he hasnt!) And BTW many people consider top-posting as you have done to be rude (just to warn you...) Mike. >By using the field axioms >(http:// mathworld.wolf ra m.com/FieldAxioms.html) >first you can show (-1)(-1) = 1: >(-1)(-1) = (-1)(-1) + 0 > = (-1)(-1) + (-1) + 1 > = (-1)[(-1) + 1] + 1 > = (-1) * 0 + 1 > = 0 + 1 = 1 >and that (-1)a = (-a): >(-1)a = (-1)a + 0 > = (-1)a + a + (-a) > = a[(-1) + 1] + (-a) > = a * 0 + (-a) > = 0 + (-a) = (-a) >So (-a)(-b) = (-1)a * (-1)b > = (-1)(-1)ab > = 1 * ab = ab. === Subject: Riddle to solve.... by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBL2R6O17138; I am in the sea BUT not in the water I start in March and end in December You find me neither in peace nor war Many have me but few dont I am in the shadows but not in a dark place === Subject: Re: Riddle to solve.... > I am in the sea BUT not in the water > I start in March and end in December > You find me neither in peace nor war > Many have me but few dont > I am in the shadows but not in a dark place Please post riddles in the rec.puzzles news group rather than a mathematical group. Ken Pledger. === Subject: Please help Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 at -2 and a local min value of 0 at 1. -- submissions: post to k12.ed.math or e-mail to k12math@k12groups.org private e-mail to the k12.ed.math moderator: kem-moderator@k12groups.org newsgroup website: http://www.thinkspot.net/k12math/ newsgroup charter: http://www.thinkspot.net/k12math/charter.html === Subject: Re: Please help > Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 at -2 > and a local min value of 0 at 1. Cant be done as stated. Coefficient of x^3 cant be 9. If you mean f(x) = a x^3 + b x^2 + c x + d, then it becomes possible. === Subject: Re: Please help > Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 > at -2 > and a local min value of 0 at 1. I think you meant f(x) = ax^3+bx^2+cx+d. (a is not necessarily 9). Now f Ô(x) = 3ax^2+2bx+c must be 0 when x = -2 (local max) or when x=1 (local min), so f Ô(x) must factor as f Ô(x) = 3ax^2+2bx+c = 3a ( x - 1 ) ( x + 2 ) Multiplying this out and solving for b and c, we find that b = 3a/2 and c = -6a So f(x) = ax^3 + ( 3 / 2 )ax^2 - 6ax + d Now we also have that f(-2) = -8a + 6a + 12a + d = 10a + d = 3 and f(1) = a + ( 3 / 2 )a - 6a + d = ( -7 / 2 )a + d = 0 Solving this for a and d gives us a = 2 / 9 and d = 7 / 9 and therefore b = 1 / 3 and c = -4 / 3 So the cubic you seek is f(x) = ( 2 / 9 ) * x^3 + ( 1 / 3 ) * x^2 - ( 4 / 3 ) * x + 7 / 9 -- submissions: post to k12.ed.math or e-mail to k12math@k12groups.org private e-mail to the k12.ed.math moderator: kem-moderator@k12groups.org newsgroup website: http://www.thinkspot.net/k12math/ newsgroup charter: http://www.thinkspot.net/k12math/charter.html === Subject: Re: Please help | Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 at -2 | and a local min value of 0 at 1. | | | f(x) = 27 x^2 + 2bx + c f(x) = 54x + 2b At local min or max, f(x) = 0. Also, f(x) > 0 for min and < 0 for max. -- submissions: post to k12.ed.math or e-mail to k12math@k12groups.org private e-mail to the k12.ed.math moderator: kem-moderator@k12groups.org newsgroup website: http://www.thinkspot.net/k12math/ newsgroup charter: http://www.thinkspot.net/k12math/charter.html === Subject: Re: Please help > Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 at -2 > and a local min value of 0 at 1. f(x) = ax(x - 3)(x + 2) -- submissions: post to k12.ed.math or e-mail to k12math@k12groups.org private e-mail to the k12.ed.math moderator: kem-moderator@k12groups.org newsgroup website: http://www.thinkspot.net/k12math/ newsgroup charter: http://www.thinkspot.net/k12math/charter.html === Subject: Re: Please help > Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 at -2 > and a local min value of 0 at 1. f(x) = ax(x + 2)(x - 3) === Subject: Re: Please help >>Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 at -2 >>and a local min value of 0 at 1. > f(x) = ax(x + 2)(x - 3) Why should (1) the derivative of a cubic be a cubic? (2) the derivative have zeros at 0 and 3? Just curious. Why I ask: (1) A polynomial of degree n has a polynomial of degree n-1 as its derivative. (2) Generally, one looks for local extrema to occur at zeros of the derivative. Dale. Dale === Subject: Re: Please help >>Find a cubic fcn f(x)=9x^3 +bx^2+cx+d that has a local max value of 3 at -2 >>and a local min value of 0 at 1. > f(x) = ax(x + 2)(x - 3) > Why should > (1) the derivative of a cubic be a cubic? > (2) the derivative have zeros at 0 and 3? f(x) = a(x + 2)(x - 1) === Subject: householder matrices I am a bit confused by the definition of a Ôhouseholder matrix. According to the texts I have come across , the householder matrix is defined as :- H = I - 2 x x^T Where I is the identity matrix, and Ôx a vector. What I dont understand is that the term Ô2 x x^T is a scalar and not a matrix, so how can you subtract a scalar from a matrix?? Also does the definition of the householder matrix extend to complex matrices? so that the definition maybe has the analogue :- H = I - 2 x x^H Where ÔH is the Hermittian. Would that expression hold for the complex case? === Subject: Re: householder matrices by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBLEbZa12134; >I am a bit confused by the definition of a Ôhouseholder matrix. According >to the texts I have come across , the householder matrix is defined as :- >H = I - 2 x x^T >Where I is the identity matrix, and Ôx a vector. What I dont understand >is that the term Ô2 x x^T is a scalar and not a matrix, so how can you >subtract a scalar from a matrix?? >Also does the definition of the householder matrix extend to complex >matrices? so that the definition maybe has the analogue :- >H = I - 2 x x^H >Where ÔH is the Hermittian. Would that expression hold for the complex >case? Jeremy, Think of x as a n by 1 matrix. Then x^T x is a 1 by 1 matrix, i.e. a scalar, and x x^T is an n by n matrix where the (i,j) element is (x_i)(x_j). Clearly, x x^T is symmetric. Yes, there is a Hermitian generalization just as you suspect. Householder matrices are used in the QR decomposition of a matrix. Each Householder transformation is unitary (or simply orthogonal in the real case) as can be easily verified by taking h h^H. (Here is am using lower case Ôh for the Householder matrix so as not to confuse it with the ÔH for Hermittian.) There is a very simply algorithm to chose n Householder matrices such that any matrix A can be decomposed into A = QR where Q is the unitary matrix resulting from the product of the Householder matrices and R is upper triangular. See http://planetmath.org/encyclopedia/ HouseholderTransformation.html - MO === Subject: Re: householder matrices Jeremy Watts dixit: >I am a bit confused by the definition of a Ôhouseholder matrix. According >to the texts I have come across , the householder matrix is defined as :- >H = I - 2 x x^T >Where I is the identity matrix, and Ôx a vector. What I dont understand >is that the term Ô2 x x^T is a scalar and not a matrix, so how can you >subtract a scalar from a matrix?? x is a n-dimensional unit column vector, so x^T, which means transpose of x, is a row vector. When you multiply, you get an n x n matrix which consists of dot products, not a scalar. So this formula is correct, in fact its the formula for a reßection across the line which has x as a unit direction vector. Thats what a Householder matrix is, if I remember correctly. (Its easy to derive this formula if you make a drawing in 3d, for example, using vectors). >Also does the definition of the householder matrix extend to complex >matrices? so that the definition maybe has the analogue :- >H = I - 2 x x^H >Where ÔH is the Hermittian. Would that expression hold for the complex >case? I dont know but you could try for some complex vector x to apply the formula. Then matrix H must be a reßection, so it must have the properties of a reßection like det(H)=-1 and H^2 = Identity, and it must be orthogonal. === Subject: Re: householder matrices by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBLG9Fw21486; >Jeremy Watts dixit: >>I am a bit confused by the definition of a Ôhouseholder matrix. According >>to the texts I have come across , the householder matrix is defined as :- >>H = I - 2 x x^T >>Where I is the identity matrix, and Ôx a vector. What I dont understand >>is that the term Ô2 x x^T is a scalar and not a matrix, so how can you >>subtract a scalar from a matrix?? >x is a n-dimensional unit column vector, so x^T, which means transpose >of x, is a row vector. When you multiply, you get an n x n matrix >which consists of dot products, not a scalar. So this formula is >correct, in fact its the formula for a reßection across the line >which has x as a unit direction vector. Thats what a Householder >matrix is, if I remember correctly. (Its easy to derive this formula >if you make a drawing in 3d, for example, using vectors). >>Also does the definition of the householder matrix extend to complex >>matrices? so that the definition maybe has the analogue :- >>H = I - 2 x x^H >>Where ÔH is the Hermittian. Would that expression hold for the complex >>case? >I dont know but you could try for some complex vector x to apply the >formula. Then matrix H must be a reßection, so it must have the >properties of a reßection like det(H)=-1 and H^2 = Identity, and it >must be orthogonal. h = I - 2 x x^H is unitary, i.e. (h)(h^H) = (h^H)(h) = I. h^2 will not necessarily equal I. - MO === Subject: testing just testing === Subject: testing just testing === Subject: Book To Do and Learn Math Equations? Can anyone recommend a math textbook with problems I can practice on? I am wanting to learn more on the equations as they pertain to physics (for example, string theory, etc...).....I see these equations...I just want to know how to read and solve them. Would differential equations be a good place to start? BTW, I do have some math background (calculus, diff equations, physics....about 12 years ago). === Subject: Re: Book To Do and Learn Math Equations? by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBLFfMK18704; Anthony http://mathforum.org/epigone/alt.math.undergrad/lunswonggen > Can anyone recommend a math textbook with problems I can > practice on? I am wanting to learn more on the equations > as they pertain to physics (for example, string theory, etc...) > .....I see these equations...I just want to know how to > read and solve them. > Would differential equations be a good place to start? > BTW, I do have some math background (calculus, diff equations, > physics....about 12 years ago). Id suggest getting one of those texts for a two semester advanced undergraduate level math for engineers and physicists type course -- mostly to review and fill in your gaps (see [1]), and then when youre finished with it, begin working through one of the texts used for a two semester beginning graduate level mathematical methods course (see [2]). [1] Mathematical Methods in the Physical Sciences by Mary L. Boas Advanced Engineering Mathematics by Erwin Kreyszig (a solutions manual is available) [2] Mathematical Methods of Physics by Jon Mathews and Robert L. Walker (this is probably more mid-way between [1] and [2] than it is [2]) Mathematical Methods for Physicists by George B. Arfken, Hans J. Weber, Hans-Jurgen Weber Methods of Theoretical Physics by Philip M. Morse and Herman Feshbach Incidentally, a nice text that focuses a lot on asymptotic analysis in a way that is both applied and quite mathematically rigorous is Advanced Mathematical Methods for Scientists and Engineers by Carl Bender and Steven Orszag [1] and [2] wont get you anywhere near where what youre looking for, but itll give you the foundation to (co-currently with [2] would be best) go through the standard graduate level stuff in physics that everything later rests on, namely classical mechanics (Goldsteins book), classical electrodynamics (Jacksons book), and quantum mechanics (Merzbacher, Schiff, Messiah). By this point (if not well before), you should have enough background, along with knowing your own strengths and interests, to know what you want to begin specializing in. For something like string theory, youre going to need quite a bit of pure mathematics along the lines of topology, functional analysis, differential geometry, etc. But unless youre primarily interested in mathematics, youd probably be best served by going through [1] and [2] first, especially if youre doing this on your own. Dave L. Renfro === Subject: Re: JSH: Did you ever finish your FLT proof? > May I know in what message JSH talks about FLT? -- Will Twentyman email: wtwentyman at copper dot net === Subject: Re: need a ruler? go to my free online/onscreen ruler project > > Did you ever need an online ruler while you were sitting in front of > your computer? now you can come to this page and use this website to > measure things. > http://home.earthlink.net/~moon8500/davidmoon.html On the other hand, if I want to measure accurately, Ill get a real ruler. Yours is not accurate on my monitor. -- Will Twentyman email: wtwentyman at copper dot net === Subject: Empty SET by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBLG2cg21109; Hi everyone, I want to ask about a partition of a set. we know for a set of set to be a partition for A there is 3 conditions must satisfy: 1-Empty set isnt belong to the partition i.e.none of the set of the partition must be the empty set. why does this condition is important ??? can anyone explain to me .. === Subject: Re: Empty SET > Hi everyone, > I want to ask about a partition of a set. > we know for a set of set to be a partition for A there is 3 conditions > must satisfy: > 1-Empty set isnt belong to the partition i.e.none of the set of the > partition must be the empty set. > why does this condition is important ??? > can anyone explain to me .. In some elementary situations it mightnt do much harm to include the empty set. However, it causes trouble if you need to _count_ the equivalence classes, e.g. in the proof of Lagranges Theorem in group theory. The empty class would increase the count by one, messing up such properties. Ken Pledger. === Subject: Re: Pells eq. algorythms by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBLG9Fb21490; (oops)!=all the primes of X^2+5*Y^2 of form 4*k+3 >Hi Todd, >I gave -up on showing my method for d=61. >That is because I want to simplify my presentation of the method for >which I have a proof that It works allways.I presented in writing to >Mr.Prof K.Sound from University Of Michigan and some of it before that >to another professors. >You are going to see what Euler miss to find. >I never seen any where this :in no elemenetary theory of numbers books >or advanced ones.Well ,it is only elementary high school algebra! >Here is a simple exemple: > Lets choose D=29. > Lets choose a<(29)^(1/2)>a+1 > a=5 > Now we write: > 5^2-29=(1)*(-4) > b^2-29=-4*k >We choose b as being the largest number <(29)^(1/2)such that > b+5 is divisible by 4 and we continuu the algorithm following this >rule. >so we have: > 5^2-29=(1)*(-4) I > 3^2-29=-4*5 II > 2^2-29=-5*5 III > 3^2-29=-5*4 > 5^2-29=-4*1 >Now we know that (a^2+s*b^2)*(c^2+s*d^2)=(a*c-s*b*d)^2+s*(a*d+b*c)^2 >So we multiply I*II=a^2-29*b^2=5*(4)^2 > The proof shows that 4^2 simplifies and we get; > I=c^2-29*d^2=5 > Now we multiply (I)*III= e^2-29*f^2=-5*5^2 >After we divide by 5^2 we continuu this algorithm to the end and get > x^2-29*y^2=-1 >Now we multiply this identity by itself and get > X^2-29*Y^2=1 > The proof is elementary high school algebra technique. >How in the world Euler miss to find this algorythm and he never was >able to proof Pells equation. >More than that.It took for him 7 years to proof that a prime=4*k+1 >can be represented as a^2+b^2 and to get a method how to find this >representation.Whereas this algorithm which i called Fermats >Algorythm shows how to do it: > As you see we got above the solution > x^2+1=29*y^2 > We can get from above > a^2+1=29*b where a <29 and apply Fermats algorythm > c^2+1=b*e where c+a=b*v > ......... > ......... > x^2+1=y*1 > Now we do the multiplication and get the representation > X^2+Y^2=29 > We y*1 as the last product. > Well is needed only high school algebra to show that if we have > x^2+s=D*b > then in the last product y*v we have 1In this way Fermat proved all his statements about the representations >of diferrent primes .I proved them too. >Try the one about that all the primes of > X^2+5*Y^2 have as the last digit 3 or 7 >I am not beating the bush aroun in this letter(oops!) > >Hi Todd, >Well, I apreciate very much your answer. >>Sure. Well, it was my pleasure. >I observed the diference in the notation : I used A and you use D >>Makes no difference. >I think this is coming from the the books we studied. >>Well, my solution comes from my own playing around with the >>problem, not from books. Although I have read a few in my life :) >Did you ever tried or see the cyclic method used in India back in >>800 >A.D to find the solutions? >>No, but it sounds interesting. Why dont you tell us about it? >>The word cyclic reminds me of the fact that the integers which >>pop out of the continued fraction method are palindromic (e.g. >>2, 1, 1, 1, 2 in my example). >Did you wonder If Archimedes had a method to solve the eq. when in >theCatlle >story- problem he get us to resolve a Pells equation at the end of >calculations? >>I seem to recall reading something about this in the American >>Mathematical Monthly some years ago. I recall the discussion >>was very interesting and maybe Ill dig it up and reread it, now >>that you bring it up. >Did you ever wonder what was Fermats method to resolve it? >>Well, I havent studied Fermat. I have the impression that he >>used his method of descent to solve a great many problems, and >>I half-expect youll be telling me something more about this. >Well , I know,in this Age we are conditioned to be very pragmatic, >learn to use a method well and be able to Aply it.So less and less >>we >dont have time to wonder >or find diferent ways to resolve a problem. >>Use of words like conditioned, or imputations that people >>(like me, presumably) dont wonder any more, are rather obnoxious >>and presumptuous, dont you think? If you want to have a discussion, >>then you should really be more polite, my friend. >I think you are very nice for writing down for me the use of >continuu >fractions in this > case ,but I was looking beyond this when I put the question.I >mean,I >wanted to hear some original coming from Wondering. >>down something I knew, thinking it was a real question (and not >>some sort of challenge, which is how it looks to me now). Ill >>try to be more careful next time. >Yes, You gave me the case D=61.In one day,two,three days from now I >can show to you my algorythm which I call Fermats algorythm.Well >,this algorythm is much simple than what your preference(my >opinion).This algorythm shows how Fermat used it to proof his >staments about representations of different primes too. >In another words it opens a Window in the Hystorie of past >methods >>Well, great! Im always pleased to learn new things. I do >>think the method I gave is pretty simple, and I suspect that at >>some level other solutions are in some sense equivalent, but Ill >>wait to hear more from you. >Remember, Euler was a master of Algorithms and he fail to find one >>for >Pellequation >Some Professors know about this method because I PUT IT OUT ,I have >shown it to > them in writting.But you have to show to me that you look a little >bit in the Hyistory of mathematics.Take a course If you did not or >studied it by yourself. >It is fascinated and insight inspiring.That if you like mathematics >>Well, I congratulate you on your successes with Professors, but... >>I have to show you *what*? >>I congratulate you further -- youve got quite a lot of nerve. >>Todd Trimble === Subject: Re: Pells eq. algorythms by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iBKMlYj30260; Hi Todd, I am sorry.It is possible that My humor is of bad taste to you II was beating the bush in mathematicsliketerms I will stop it. made the observation I apologise again george ghiata >>Hi Todd, >>Well, I apreciate very much your answer. >Sure. Well, it was my pleasure. >>I observed the diference in the notation : I used A and you use D >Makes no difference. >>I think this is coming from the the books we studied. >Well, my solution comes from my own playing around with the >problem, not from books. Although I have read a few in my life :) >>Did you ever tried or see the cyclic method used in India back in >800 >>A.D to find the solutions? >No, but it sounds interesting. Why dont you tell us about it? >The word cyclic reminds me of the fact that the integers which >pop out of the continued fraction method are palindromic (e.g. >2, 1, 1, 1, 2 in my example). >>Did you wonder If Archimedes had a method to solve the eq. when in >>theCatlle >>story- problem he get us to resolve a Pells equation at the end of >>calculations? >I seem to recall reading something about this in the American >Mathematical Monthly some years ago. I recall the discussion >was very interesting and maybe Ill dig it up and reread it, now >that you bring it up. >>Did you ever wonder what was Fermats method to resolve it? >Well, I havent studied Fermat. I have the impression that he >used his method of descent to solve a great many problems, and >I half-expect youll be telling me something more about this. >>Well , I know,in this Age we are conditioned to be very pragmatic, >>learn to use a method well and be able to Aply it.So less and less >>dont have time to wonder >>or find diferent ways to resolve a problem. >Use of words like conditioned, or imputations that people >(like me, presumably) dont wonder any more, are rather obnoxious >and presumptuous, dont you think? If you want to have a discussion, >then you should really be more polite, my friend. >>I think you are very nice for writing down for me the use of continuu >>fractions in this >> case ,but I was looking beyond this when I put the question.I mean,I >>wanted to hear some original coming from Wondering. >down something I knew, thinking it was a real question (and not >some sort of challenge, which is how it looks to me now). Ill >try to be more careful next time. >>Yes, You gave me the case D=61.In one day,two,three days from now I >>can show to you my algorythm which I call Fermats algorythm.Well >>,this algorythm is much simple than what your preference(my >>opinion).This algorythm shows how Fermat used it to proof his >>staments about representations of different primes too. >>In another words it opens a Window in the Hystorie of past methods >Well, great! Im always pleased to learn new things. I do >think the method I gave is pretty simple, and I suspect that at >some level other solutions are in some sense equivalent, but Ill >wait to hear more from you. >>Remember, Euler was a master of Algorithms and he fail to find one >for >>Pellequation >>Some Professors know about this method because I PUT IT OUT ,I have >>shown it to >> them in writting.But you have to show to me that you look a little >>bit in the Hyistory of mathematics.Take a course If you did not or >>studied it by yourself. >>It is fascinated and insight inspiring.That if you like mathematics . >Well, I congratulate you on your successes with Professors, but... >I have to show you *what*? >I congratulate you further -- youve got quite a lot of nerve. >Todd Trimble === Subject: Intergrate[acrtan x] dx Hi! I am trying to integrate arctan x, but doesnt get the right answer. Here is what I am doing: I[ arctan x ] dx = I[ 1 * arctan x ] dx substitute u = arctan x, v = 1 x* arctan x - I[ 1/(1+x^2) * x]dx the latter fraction is becoming x/(1+x^2), how do I integrate this one? Maybe I am missing something here.. -- === Subject: Re: Intergrate[acrtan x] dx >Hi! >I am trying to integrate arctan x, but doesnt get the right answer. Here is >what I am doing: >I[ arctan x ] dx = I[ 1 * arctan x ] dx >substitute u = arctan x, v = 1 >x* arctan x - I[ 1/(1+x^2) * x]dx >the latter fraction is becoming x/(1+x^2), how do I integrate this one? >Maybe I am missing something here.. You could let z = x^2, so that dz = 2x dx. Brian === Subject: Re: Intergrate[acrtan x] dx >>Hi! >>I am trying to integrate arctan x, but doesnt get the right answer. Here is >>what I am doing: >>I[ arctan x ] dx = I[ 1 * arctan x ] dx >>substitute u = arctan x, v = 1 >>x* arctan x - I[ 1/(1+x^2) * x]dx >>the latter fraction is becoming x/(1+x^2), how do I integrate this one? >>Maybe I am missing something here.. >You could let z = x^2, so that dz = 2x dx. >Brian Better yet, let z = 1 + x^2 and you get dz = 2x dx. Brian === Subject: Re: Intergrate[acrtan x] dx >Hi! >I am trying to integrate arctan x, but doesnt get the right answer. Here >is >what I am doing: >I[ arctan x ] dx = I[ 1 * arctan x ] dx >substitute u = arctan x, v = 1 >x* arctan x - I[ 1/(1+x^2) * x]dx >the latter fraction is becoming x/(1+x^2), how do I integrate this one? >Maybe I am missing something here.. >>You could let z = x^2, so that dz = 2x dx. >>Brian > Better yet, let z = 1 + x^2 and you get dz = 2x dx. > Brian -- Ronny M === Subject: Re: computing the logarithm of arbitrary base >> hey folks, silly question from someone who prolly never should have embarked >> on a 3 year bachelors degree in mathematics... anyway, i would like to >> compute the b-base logarithm of a number, but my calculator seems only allow >> me the bases e and 10... hints anyone?? > Learn mathematics, ditch the stupid calculator. > Have any of them ever passed a math class? > Stick with them and youll be doing the same. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Well said. Students are getting too dependent on technology for EVERYTHING and are getting the wrong idea about what mathematics is. Aristotle Polonium + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + === Subject: Re: computing the logarithm of arbitrary base >hey folks, silly question from someone who prolly never should have embarked >on a 3 year bachelors degree in mathematics... anyway, i would like to >compute the b-base logarithm of a number, but my calculator seems only allow >me the bases e and 10... hints anyone?? log_b(x) = log_10(x) / log_10(b) http://oakroadsystems.com/math/loglaws.htm#NewBase -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://OakRoadSystems.com/ Dont move, or Ill fill you full of [... pause ...] little yellow bolts of light. -- Farscape, first episode === Subject: Re: Is zero even or odd? > How many universes are in a black hole ? > Oh, this sounds like even more fun. Something we know even less > about ... > I would say about a black-holes-worth. Well, if theres at least one universe inside a black hole, then that universe could contain another black hole, and so forth. Because of the Schwarzschild radius, the is at least one universe inside the black hole separate from ours. By induction, the answer is: infinitely many. Michael -- Still an attentive ear he lent Her speech hath caused this pain But could not fathom what she meant Easier I count it to explain She was not deep, nor eloquent. The jargon of the howling main -- from Lewis Carroll: The Three Usenet Trolls === Subject: Re: Is zero even or odd? > 0 cant be divided by itself, >> Sure it can: 0 / 0 = 0 * (1 / 0) = 0 * infinity = 1 >> It works if the only three numbers in the universe are >> 0, 1, and infinity -- A number system that seems very >> suited to usenet. >Except for the fact that: 0 / 0 = undefined >Or actually more correct: n / 0 = undefined >> The two are not the same. >> The definition of the ratio a/b is >> a/b = r iff b*r = a >> for the case of n/0 there is no r such that r*0 = n (follows from the >> definition of zero. Therefore n/0 (for non zero n) *does not exist*. >> On the other hand, for 0/0, every r qualifies since for every r, r*0 = >> 0 (the definition of zero, again). Therefore, 0/0 is truly undefined, >> in the sense that it is impossible to *uniquely* assign a value to the >> ratio r. >> Mati Meron | When you argue with a fool, >> meron@cars.uchicago.edu | chances are he is doing just the same >It depends on how you get there, [sin(x)]/x is certainly defined for all >values of x including 0 and infinity. Thats a different thing. Here youre talking not about a plain value but a limit (of an infinite set of values). And this depends how you get there. Thus, [sin(0)]/0 is undefined. On the other hand, lim_x->0 {[sin[x]/x} is defined and equal to 1. Mati Meron | When you argue with a fool, meron@cars.uchicago.edu | chances are he is doing just the same === Subject: Re: Is zero even or odd? > 0/0 is clearly, if anything, a constant expression. And it turns out > [to some] that its value is undefined. > Better minds than can be found here have argued this and not reached > any conclusion. ÔUndefined is the answer given by the teacher in the > 7th grade, and will serve for all practical purposes. > Maybe what is needed is a New Number = Ô* (or something) = Any Number You > Want. > Just FYI, if youre performing arithmetic using the IEEE 754 standard, I doubt if there are any mathematicians who care a hoot about definitions made by engineers for computational convenience Franz === Subject: Re: Is zero even or odd? 0/0 is clearly, if anything, a constant expression. And it > turns out > [to some] that its value is undefined. Better minds than can be found here have argued this and not > reached > any conclusion. ÔUndefined is the answer given by the teacher in > the > 7th grade, and will serve for all practical purposes. Maybe what is needed is a New Number = Ô* (or something) = Any > Number You > Want. > Just FYI, if youre performing arithmetic using the IEEE 754 > standard, > I doubt if there are any mathematicians who care a hoot about > definitions made by engineers for computational convenience Well, then, how about yall stop crossposting from Hell to breakfast? Followups set. Xho -- -------------------- http://NewsReader.Com/ -------------------- Usenet Newsgroup Service $9.95/Month 30GB === Subject: Re: Is zero even or odd? > 0 cant be divided by itself, Sure it can: 0 / 0 = 0 * (1 / 0) = 0 * infinity = 1 It works if the only three numbers in the universe are > 0, 1, and infinity -- A number system that seems very > suited to usenet. >>Except for the fact that: 0 / 0 = undefined >>Or actually more correct: n / 0 = undefined > The two are not the same. > The definition of the ratio a/b is > a/b = r iff b*r = a > for the case of n/0 there is no r such that r*0 = n (follows from the > definition of zero. Therefore n/0 (for non zero n) *does not exist*. > On the other hand, for 0/0, every r qualifies since for every r, r*0 = > 0 (the definition of zero, again). Therefore, 0/0 is truly undefined, > in the sense that it is impossible to *uniquely* assign a value to the > ratio r. > Mati Meron | When you argue with a fool, > meron@cars.uchicago.edu | chances are he is doing just the same > It depends on how you get there, [sin(x)]/x is certainly defined for all > values of x including 0 and infinity. If you knew any maths worth talking about, you would have known that sin(0) / 0 is not the same as the limit of sin(x) / x as x tends to 0. The first is undefined and the second is unity. Now it is your turn: What do you know about sin (infinity) / infinity ? Franz === Subject: Re: Is zero even or odd? > 0 cant be divided by itself, >> Sure it can: 0 / 0 = 0 * (1 / 0) = 0 * infinity = 1 >> It works if the only three numbers in the universe are >> 0, 1, and infinity -- A number system that seems very >> suited to usenet. Except for the fact that: 0 / 0 = undefined Or actually more correct: n / 0 = undefined > The two are not the same. >> The definition of the ratio a/b is >> a/b = r iff b*r = a >> for the case of n/0 there is no r such that r*0 = n (follows from > the >> definition of zero. Therefore n/0 (for non zero n) *does not > exist*. >> On the other hand, for 0/0, every r qualifies since for every r, > r*0 = >> 0 (the definition of zero, again). Therefore, 0/0 is truly > undefined, >> in the sense that it is impossible to *uniquely* assign a value to > the >> ratio r. >> Mati Meron | When you argue with a fool, >> meron@cars.uchicago.edu | chances are he is doing just > the same >> It depends on how you get there, [sin(x)]/x is certainly defined > for all >> values of x including 0 and infinity. > If you knew any maths worth talking about, you would have known that > sin(0) / 0 is not the same as the limit of sin(x) / x as x tends to 0. > The first is undefined and the second is unity. Tell that to all the book publishers who print curves for sinx/x. > Now it is your turn: What do you know about sin (infinity) / infinity > Franz No problem. Sin x is bounded between +/- 1 for all values of x. A finite number divided by infinity is 0. Tam === Subject: Re: Is zero even or odd? ) )> If you knew any maths worth talking about, you would have known that )> sin(0) / 0 is not the same as the limit of sin(x) / x as x tends to 0. )> The first is undefined and the second is unity. ) Tell that to all the book publishers who print curves for sinx/x. If you zoom in on those printed curves far enough, youll notice that there is no ink at the actual point (0,1). SaSW, Willem -- Disclaimer: I am in no way responsible for any of the statements made in the above text. For all I know I might be drugged or something.. No Im not paranoid. You all think Im paranoid, dont you ! #EOT === Subject: Re: Is zero even or odd? >> I know 0 is neither negative or positive but what about odd/even? I > think >> its even. > It is essentially neutral for it signifies a number that isnt there > because it lacks quantity. It is the symbol for nothingness therefore > it isnt odd nor even. For example, take the addition of all numbers > from -infinity to +infinity, what do you > get?...zero!...nothin!....nada! The sum of everything is equal to > nothing! > In physics, the conservation of energy states that no energy can be > created or destroyed. Therefore, if you add up all of the negative > potential energy in the universe with the positive kinetic energy, you > get NOTHING!....hence the total energy in the universe is zero. > Therefore, we are all essentially made up of nothing. > Sleep tight! If you have two apples and you eat the two apples there are now no apples in the whole of an infinite Universe? Zero? What of the term ground zero? Does it mean no ground? What of quality, or is it quantity, infinite zero? Zero point energy? Running a zero balance? Hawking time zero on the clock? My own four dimensions of time in which one dimension is zero (history (pasts-futures), frequency, relativity (gain in and loss of), and zero)? Zeroing in on? And, most particularly, base2, base4, base8, base16.....? Zero can be an anchor. mathematicians in the early twentieth century conceived monstrous-seeming objects made by the technique of adding or removing infinitely many parts. One such shape is the Sierpinski carpet, constructed by cutting the center one-ninth of a square; then cutting out the centers of the eight smaller squares that remain; and so on. The three-dimensional analogue is the Menger sponge, a solid-looking lattice that has an infinite surface area, yet zero volume. Brad