# Thread: Taylor Series

1. ## Taylor Series

Find the Taylor Series for f(x) centered at $a=11\pi$

f(x) = 4 cos(x)

I got:

$\sum^{\infty}_{n=0} (-1)^n \frac{4(x-11\pi)^{2n}}{(2n)!}$

What did I do wrong on this? I was confused about how to evaluate at $11\pi$

Since at n=0, I did not get a 0, I didn't think I needed to have (2n+1)

2. Hello,

But cos(0)=1, so you're supposed to get 1, not 0, when n=0.
Which is the case here.

Your formula is correct !

3. Originally Posted by Moo
Hello,

But cos(0)=1, so you're supposed to get 1, not 0, when n=0.
Which is the case here.

Your formula is correct !
I think you misread my post, I didn't get 0 at n=0, I got $cos(11\pi) = -1$

Thanks for verifying my formula!!!