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You are not logged in. #1 20060314 00:32:48
1²+2²+3²+...+n²=? without using inductionthe answer seems too odd for me n(n+1)(2n+1)/6, and what mathematical induction can do is just to prove other than to derive. Hoping some genius could handle this out, with ease and simplisity, like the derivation of 1+a+a²+a³+...+an X'(yXβ)=0 #2 20060314 00:42:34
Re: 1²+2²+3²+...+n²=? without using inductionI don't see why you don't want it to be using induction, but whatever. I remember that question being asked here before, so there'll be a topic here somewhere with a proof. I remember that it has an induction proof and a different proof as well, so you get two answers! Last edited by mathsyperson (20060314 00:43:42) Why did the vector cross the road? It wanted to be normal. #4 20060314 14:53:32
Re: 1²+2²+3²+...+n²=? without using inductionThank you for the link. The link finally reminded me of the proof i once read in Thomas' Calculus book, it uses a neighbor elimation trick: X'(yXβ)=0 #5 20060319 02:31:06
Re: 1²+2²+3²+...+n²=? without using inductionHi. is very useful for calculating sums. That's because: If you want to calculate this: , you may express the f(x) = x^i as: , where r(x) is the "remainder", which has less power than f(x). Example for f(x)=x^1: S_2 (x) = (x+1)^2x^2=x^2+2x+1x^2=2x+1 (S_2 (x))/2=x+1/2 f(x)=x^1=x=0.5 S_2(x)  0.5 = 0.5(S_2(x)1). So . There's also and binomial proof, which is more usable and universal, but it's harder too. IPBLE: Increasing Performance By Lowering Expectations. #6 20060320 13:45:22
Re: 1²+2²+3²+...+n²=? without using inductionGood proof! Thanks a lot Last edited by George,Y (20060320 13:51:28) X'(yXβ)=0 #7 20060401 06:45:05
Re: 1²+2²+3²+...+n²=? without using inductionYes, thank you. IPBLE: Increasing Performance By Lowering Expectations. 