what are the first three nozero terms of the Taylor series for f(x) = cos(x) about x = -Pi?
The Taylor series expansion for a function f(x) about the point x = a is given by:
So in your case,
and
The process is just a matter of starting with the first term in the above series, inserting your function evaluated at , and doing any necessary derivatives, etc, to see if it vanishes or not. Then proceed to the next term, and so on, until you have three nonvanishing terms.