- #1

Daveyboy

- 58

- 0

## Homework Statement

integral 1/(a+cos(t))^2 from 0 to pi.

## Homework Equations

cos(t)=1/2(e^it+e^-it)

z=e^it

dz/(ie^it)=dt

## The Attempt at a Solution

int dt/(a+cos(t))^2 = int dz/iz(a

^{2}+az+az

^{-1}+z

^{2}/4 +1/2 +z

^{-2}/4)

so with these types of problems I normally can factor this guy some how and get a nice looking quadratic to find the roots and calculate the residue and I'm done. I don't know what to do with this thing in the denominator how can I find the poles of this guy?