You left out the factorial (2i)! in the denomiator.

And what's wrong with the upper limit of your sum being n?

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- May 2nd 2009, 10:32 PM #1

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## sumation of cos x

Write the summation notation of the maclaurin polynomial of order n for cos x

then for the sumation i got this

My question is what goes on top of the sigma? The top part is the stopping point when computing the sum, correct? I need to find the Nth so the top is not infinity.

Let's say I want the thrid maclaurin, n =3. would that be

or

counting on zero but the 0 coeffients remove those odd powered x's so the above is just the same as the previous.

With x^2i that will take into acount the 0 coeffients, for when sine at 0. It out puts 1, x^2, x^4 ..., so that forms the first example of the thrid maclaurin. Does that mean the top of sigma is just n?

The thing is my teacher wrote something like int[n/2 + 1.5] as the top of sigma but said he wasnt sure of that. and after runing different forms n/2 +.5, n/2 +1 it doesnt make sense to me why you would need something like that. the top part is just the stoping point so why the heck do you even need a little equation on the top ?!.

grrr

- May 2nd 2009, 11:06 PM #2

- May 2nd 2009, 11:25 PM #3

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- May 2nd 2009, 11:29 PM #4

- May 2nd 2009, 11:38 PM #5

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- May 2nd 2009, 11:52 PM #6

- May 3rd 2009, 12:14 AM #7

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