mm-400 Subject: Re: middle term expansionMathematics is about recognising patterns; here are three clues:Pascal's Triangle - wch I'll bet you've heard of - gives coefficients 1,6, 15, 20, 15, 6, 1There are seven terms, the largest being x^6 and the smallest being 1/(x^6),so the middle term is just a number.The minus sign in the original expression means that the terms alternate insign, the first being positive.Putting these together the result is - 20.You have enough information to write out the full expansion but I tnk yourteacher is trying to show you that all that work is not necessary.I hope that makes it easier - Ian Hutcheson === Subject: Re: what expression represents the nth term of the sequence?> If the first term of a geometric sequence is 3/2 and the second and> trd terms are -3/4 and 3/8 respectively, what is the expression for> the nth term of the sequence? Geometric sequence: a, a*r, a*r^2, a*r^3, ...with a = 3/2, a*r = -3/4 and a*r^2 = 3/8, and so on === Subject: Re: What is the value of k? ===Subject: Re: What is the value of k?If ending in minus 15 gave remainder 7 then ending in minus 22 wouldfactorise exactly.The key information that helps solve the problem then, is that for somevalue p, say(x - 2) (x^2+px+11) = x^3+kx^2 - 3x - 22. Equating coefficients of x squaredand x:- 2 + p = k11 - 2p= - 3p=7 so k = 5I hope that makes it easy to follow - Ian Hutcheson === Subject: Re: What is the value of k?If ending in minus 15 gave remainder 7 then ending in minus 22 wouldfactorise exactly.The key information that helps solve the problem then, is that for somevalue p, say(x - 2) (x^2+px+11) = x^3+kx^2 - 3x - 22. Equating coefficients of x squaredand x:- 2 + p = k11 - 2p= - 3p=7 so k = 5I hope that makes it easy to follow - Ian Hutcheson === Subject: Re: What is the value of k?If ending in minus 15 gave remainder 7 then ending in minus 22 wouldfactorise exactly.The key information that helps solve the problem then, is that for somevalue p, say(x - 2) (x^2+px+11) = x^3+kx^2 - 3x - 22. Equating coefficients of x squaredand x:- 2 + p = k11 - 2p= - 3p=7 so k = 5I hope that makes it easy to follow - Ian Hutcheson === Subject: Re: What is the value of k?> If the remainder is 7 when x^3+kx^2-3x-15 is divided by x-2, then k= ?> Would be gratefull if you drop a few words about the way the solution goes.> ,Given any polynomial, P(x) in x, the remainder theorem says that the remainder when P(x) is divided by x-a equals the value of the polynomial when x = a, i.e., P(a) So let P(x) = x^3+kx^2-3x-15 and solve P(2) = 7 for k. === Subject: Re: Derivatives Help> I am taking a class called Circuit Analysis for Engineering.> It requires alot of Calculus concepts that I honestly forgot and the bookis> no help at all and doesnt even have any examples..> The problem that I am currently having problem with is sometng likets.> i(t) = C * dv(t)/dt> The given info is C = 0.2 F (farads) and v(t) = 4(1 - e^-10t) for t >0> They want you to determine the expression for i(t)> The answer is 8 x 10^-6 e^-10t> Now I have been trying to figure out how to do that and how they got that> answer for a long time and I am just going crazy. I was tnking that10^-6> is a conversion between Farads and MicroFarads..> I atleast want to find out what the derivative of v(t) is.> Any help is appreciated > Sports Talk Forum - http://www.houstonsportstalk.comdv/dt=40e^-10ti(t)=.2(40e^-10t )=8e^-10tI am guessing that the 10^-6 is for microfarads, as you suggest. === Subject: Re: Derivatives Help Its starting to come back to me now....slowly :)So when you have a function such as: f(x) = n(1 - e^y) ....the derivative would always be f'(x) = yn* e^y ?-- Free PC Tech Support - http://www.webzila.comSports Talk Forum - http://www.houstonsportstalk.com>> I am taking a class called Circuit Analysis for Engineering.>> It requires alot of Calculus concepts that I honestly forgot and the book> is>> no help at all and doesnt even have any examples..>> The problem that I am currently having problem with is sometng like> ts.>> i(t) = C * dv(t)/dt>> The given info is C = 0.2 F (farads) and v(t) = 4(1 - e^-10t) for t >0>> They want you to determine the expression for i(t)>> The answer is 8 x 10^-6 e^-10t>> Now I have been trying to figure out how to do that and how they got that>> answer for a long time and I am just going crazy. I was tnking that> 10^-6>> is a conversion between Farads and MicroFarads..>> I atleast want to find out what the derivative of v(t) is.>> Any help is appreciated>> -- >> Steve, I-Net+>> Free PC Tech Support - http://www.webzila.com>> Sports Talk Forum - http://www.houstonsportstalk.com> dv/dt=40e^-10t> i(t)=.2(40e^-10t)=8e^-10t> I am guessing that the 10^-6 is for microfarads, as you suggest. === Subject: Re: Derivatives Help> Its starting to come back to me now....slowly :)> So when you have a function such as: f(x) = n(1 - e^y) ....the derivative> would always be f'(x) = yn* e^y ?The derivative of e^x is e^x. For a general function e^(ax), the derivativewill be ae^(ax).Wle you're at it, it might be a good idea to learn sometng calledlogarithmic differentiation if you're good with manipulating logs. Ts willmake differentiating some functions easier and for some functions,logarithmic differentiation is the only way to go.> -- > Free PC Tech Support - http://www.webzila.com> Sports Talk Forum - http://www.houstonsportstalk.com> I am taking a class called Circuit Analysis for Engineering.>> It requires alot of Calculus concepts that I honestly forgot and thebook> is>> no help at all and doesnt even have any examples..>> The problem that I am currently having problem with is sometng like> ts.>> i(t) = C * dv(t)/dt>> The given info is C = 0.2 F (farads) and v(t) = 4(1 - e^-10t) for t >0>> They want you to determine the expression for i(t)>> The answer is 8 x 10^-6 e^-10t>> Now I have been trying to figure out how to do that and how they gotthat>> answer for a long time and I am just going crazy. I was tnking that> 10^-6>> is a conversion between Farads and MicroFarads..>> I atleast want to find out what the derivative of v(t) is.>> Any help is appreciated>> -- >> Steve, I-Net+>> Free PC Tech Support - http://www.webzila.com>> Sports Talk Forum - http://www.houstonsportstalk.com>> dv/dt=40e^-10t i(t)=.2(40e^-10t)=8e^-10t I am guessing that the 10^-6 is for microfarads, as you suggest. === Subject: Re: Derivatives Helpd/dt of 4(1-e^(-10t)) = +40e^(-10t) (take the trouble to find out why)You have told me the rest yourself, i.e. C = 0.2 x 10^6Multiply out and you are home and dryI hope that helps - Ian Hutcheson === Subject: Re: JSH: Research question answered One of the reasons I've been so fascinated by the Decker example is that it revealed to me that I wasn't exactly certain about methodologies that I'd discovered, as it seems I didn't underd exactly how everytng worked. An understatement of monumental proportions ... If the Decker example is so fascinating to you, why is it > that, in the 15-20 separate threads you have started on ts> topic, you have never ONCE quoted Decker's conclusion ? Are> you so terrified that other people might read it and realize> that Decker was totally, obviously right, and your claims to> the contrary were totally, obviously so much hot air?I will repeat that you should off.If you wish to continue replying to me, you will find you are giving> me more opportunities to tell you to OFF!!!I know now that you're not a woman. What woman would so *publicly*> stalk a guy like ts and repeatedly be told to off and keep at> it? A man comes into my neighborhood and begins screaming at the top of s lungs that my neighbors and I are morons, incompetents,welfare queens, that we are conspiring to cheat m out of s rightful recognition, that he is going to call in the FBI andthe U.S. Army, s Congressman, the President, that he has *proof* that we have been lying, etc.. I point out that s facts are wrong and give m ample opportunity to refute ts. Every day he comes back with more shrieking, wning, accusing - vicious, nasty stuff, and endless repetitions of s fundamentally unsound proof, alongwith claims that he is a misunderstood genius, etc., but no answers to what I say. I reply with additional evidence that he is wrong. He ignores ts and continues to shriek and insult the entire neighborhood. Now he gets drunk and starts howling obscenities and says I am*stalking* m !!! I'm not backing off. You are wrong and I tnk you actually know it. > Who are you really Nora Baron?> Here is another example related to that of Rick Decker,with a couple of additional twists. Let P(x) = 7*(25*x^2 + 60*x - 133). Ts can be re-written as [*] P(x) = 7*{25*(x^2 + x) + 7*(x - 4)*5 + 7}. Now assume P(x) is factored as a polynomial in the variable 5 in the form[**] P(x) = (5 a_1(x) + 7)*(5 a_2(x) + 7),where a_1(x) and a_2(x) are roots of[***] a^2 - 7*(x - 4)*a + 7*(x^2 + x). Note that when x = 0, the roots are a_1(0) = 0 and a_2(0) = 28. Both are divisible by 7. As it turns out, when x = 2, these two roots are a_1(2) = -7 + sqrt(7) and a_2(2) = -7 - sqrt(7). Both a_1(2) and a_2(2) are divisible in the algebraicintegers by sqrt(7), but neither is divisible by 7. In the factorization [**], sqrt(7) can be divided out of eachfactor to produce P(2)/7 = (5*(-sqrt(7)+1) + sqrt(7))*(5*(-sqrt(7)-1) + sqrt(7)),a factorization in wch *all the individual terms* are algebraicintegers. Note that the left side, from [*], has the value P(2)/7 = (25*4 + 60*2 - 133) = 87. You can easily check that the right side has the same value.It's gh-school arithmetic. Note that the coefficients of the last two terms in [***]have the same residue mod 7 (i.e., 0), regardless of the value of x. The value x = 2 is not an exception. I chose ts examplebecause the arithmetic is easy. An analogous factorizationexists for *most* integer values of x. The existence of suchis guaranteed by a theorem of Dedekind. You have seen ts and you know it is correct. At least you have never arguedwith it. You say ts factorization is impossible. You keep dancing and twisting around, trying to find a counterargument, based on your invalid ideas about cont terms. You have not confronted the arithmetic in Decker's original example for the obvious reason that you cannot possibly refute it. The same is true here. === Subject: Re: JSH: Research question answered> Actually, JSH's proofs work, once you underd s terminology. For> example, when he says> X, so Y> that doesn't mean Y follows from X like it does in dard terminology.> In JSH terminology, it means X is true, and now, for sometng completely> different, here is Y, wch has notng to do with X, and probably has a> counterexample in small integers, and I'm a genius.> Once you realize ts, and a couple other places where he has s own,> special, terminology, s proofs make sense, in the sense that everytng in> them is a correct statement. :-)> --> More Harristotelian logic:If A = B and B = C, then I am the greatest mathematician of all time and you areall evil subhuman conspirators. .----http://www.crbond.com === Subject: Re: JSH: Research question answered>> One of the reasons I've been so fascinated by the Decker example is>> that it revealed to me that I wasn't exactly certain about>> methodologies that I'd discovered, as it seems I didn't underd>> exactly how everytng worked.>> An understatement of monumental proportions ... If the Decker example is so fascinating to you, why is it >> that, in the 15-20 separate threads you have started on ts>> topic, you have never ONCE quoted Decker's conclusion ? Are>> you so terrified that other people might read it and realize>> that Decker was totally, obviously right, and your claims to>> the contrary were totally, obviously so much hot air?>> > off.>I will repeat that you should off.Oops. Another nt: when you reply like ts it looks,even to people who aren't following the math, that yousimply can't answer the question. Bad strategy.>If you wish to continue replying to me, you will find you are giving>me more opportunities to tell you to OFF!!!>I know now that you're not a woman. What woman would so *publicly*>stalk a guy like ts and repeatedly be told to off and keep at>it?>Who are you really Nora Baron?>************************ === Subject: Re: JSH: Research question answered> Who are you really Nora Baron?I heard a really juicy rumour that she works at Hamilton College. Does> that interest you?>And me tnking it was OK State.Interesting theory, but I don't tnk so. There are certainly expertsin algebraic number theory here, but none of them are regular sci.math participants. (Hmm, as far as I know - maybe I need toask ___ whether he's adopted a pseudonym...)************************ === Subject: Re: JSH: Research question answered>> One of the reasons I've been so fascinated by the Decker example is>> that it revealed to me that I wasn't exactly certain about>> methodologies that I'd discovered, as it seems I didn't underd>> exactly how everytng worked.>> An understatement of monumental proportions ... If the Decker example is so fascinating to you, why is it >> that, in the 15-20 separate threads you have started on ts>> topic, you have never ONCE quoted Decker's conclusion ? Are>> you so terrified that other people might read it and realize>> that Decker was totally, obviously right, and your claims to>> the contrary were totally, obviously so much hot air? **** off.I will repeat that you should **** off.If you wish to continue replying to me, you will find you are giving> me more opportunities to tell you to **** OFF!!!I know now that you're not a woman. What woman would so *publicly*> stalk a guy like ts and repeatedly be told to **** off and keep at> it?What decent man would speak that way to a woman (or another man)?But then, you're neither decent nor a man.> Who are you really Nora Baron?Clearly, she's someone who's got your number. Otherwise she wouldn'tmake you so angry by asking questions you can't answer.-- === Subject: Re: JSH: Research question answered One of the reasons I've been so fascinated by the Decker example is that it revealed to me that I wasn't exactly certain about methodologies that I'd discovered, as it seems I didn't underd exactly how everytng worked. An understatement of monumental proportions ... If the Decker example is so fascinating to you, why is it > that, in the 15-20 separate threads you have started on ts> topic, you have never ONCE quoted Decker's conclusion ? Are> you so terrified that other people might read it and realize> that Decker was totally, obviously right, and your claims to> the contrary were totally, obviously so much hot air?> off.I will repeat that you should off.If you wish to continue replying to me, you will find you are giving> me more opportunities to tell you to OFF!!!I know now that you're not a woman. What woman would so *publicly*> stalk a guy like ts and repeatedly be told to off and keep at> it?Who are you really Nora Baron?She could be someone who is more interested in truth than in your petty temper tantrums. They only show everyone how little you are worth. === Subject: JSH: Pattern argumentSo I've put out the Decker quadratic (source information at bottom),but replies from various people indicate there's still room forconfusion, so I'll give a pattern argument.The original quadratic is (5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) where s a's are roots of a^2 - (x - 1)a + 7(x^2 + x).You can modify it easily enough to getb^2 - (x - 1)b + 17(x^2 + x), where you then have(5b_1(x) + 17)(5b_2(x) + 17) = 17(25x^2 + 25x) + 17(5)(x-1) + 17^2 wch is(5b_1(x) + 17)(5b_2(x) + 17) = 17(25x^2 + 30x + 12) or you can go down toc^2 - (x - 1)c + 2(x^2 + x), wch gives you(5c_1(x) + 2)(5c_2(x) + 2) = 2(25x^2 + 25x) - 2(5)(x-1) + 2^2 wch is(5c_1(x) + 2)(5c_2(x) + 2) = 2(25x^2 + 30x - 3).So I have(5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) (5b_1(x) + 17)(5b_2(x) + 17) = 17(25x^2 + 30x + 12) and(5c_1(x) + 2)(5c_2(x) + 2) = 2(25x^2 + 30x - 3).The more astute of you should see a pattern. Clearly the contfactor on the right, wch shows up as a coefficient on the left mustequal 2 mod 5 for ts particular setup.But why?It turns out that I'm exploiting a symmetry with *integer*coefficients in the factorization.Imagine that in each case there's a base equation(5y_1(x) + 1)(5y_2(x) + 2)where you can linearly tranform the second factor (5y_2(x) + 2) rathereasily leaving you free to multiply the first factor by variousintegers as long as they equal 2 mod 5.Now if you beliee that *any* of the explanations given by variousposters out there can relate that to reducibility over Q or GaloisTheory, then you're not good with a basic pattern.The problem is that y_1(x) and y_2(x) can't both be algebraic integerfunctions.Now if you *still* are having a problem underding, ask yourself,how can anyone force a cont factor like 7, or 2, or 17 to onlywork with *one* factorization?Like consider againb^2 - (x - 1)b + 17(x^2 + x), where you have(5b_1(x) + 17)(5b_2(x) + 17) = 17(25x^2 + 30x + 12).Why does that 17 lead to *one* factorization on the left? How is itpossible for it to be limited?The answer is that there's only one way to distribute it and have*integer* coefficients in the factorization on the left.Mathematicians here need to be at least a little curious, or you'llnever figure it out!!!Tnk logically, and force people disagreeing with me to answer basicquestions, like how do they explain the pattern:(5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) (5b_1(x) + 17)(5b_2(x) + 17) = 17(25x^2 + 30x + 12) and(5c_1(x) + 2)(5c_2(x) + 2) = 2(25x^2 + 30x - 3)?Decker Quadratic Source Information---------------------Recently Rick Decker, a professor at Hamilton College, apparentlytrying to refute my research came up with a quadratic example, wch Ilike because it's a quadratic, and easier to manipulate than thecubics I've used before.If you wish to see s original post here are some headers wch alsoshow that he posts from Hamilton College: === Subject: Re: Mathematical consistency, courageDecker put forward the quadratic(5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) where s a's are roots of a^2 - (x - 1)a + 7(x^2 + x).