Question

Find the degree 3 Taylor polynomial approximation to the function f(x)=8ln(sec(x)) about the point a=0 .

Answer 1

Go to

http://www.wolframalpha.com/input/?i=8ln%28sec%28x%29%29+

and scroll down a bit.

Answer 2

I don't see what you mean..Do you mean the 8th derivative of the function?

Answer 3

Look at that link. It gives you the series expansion about zero explicitly.