Solve T4(x) for Taylor Polynomials of f(x)=arctan(11x)

[hahaha158]

Homework Statement

Find T4(x), the Taylor polynomial of degree 4 of the function f(x)=arctan(11x) about x=0.
(You need to enter a function.)

Homework Equations

The taylor polynomial equation

Tn(x)= f(x)+(fn(x)(x-a)^n)/n!...

The Attempt at a Solution

When I take every derivative of f(x)=arctan(11x) I always end up with an x in the numerator, so when i plug in 0 for x my derivative ends up with 0, so theoretically the answer would just be arctan(11x) which is wrong.

This is what I am getting for my first few derivatives

F'(x)=22x/(11x^2+1)
F''(x)=-484x^2/(11x^2+1)^-2

what am i doing wrong?

 

[lurflurf]

Those are all wrong.
F'(x)=11/(121x^2+1)
only the odd derivatives will vanish