1. The problem statement, all variables and given/known data http://img23.imageshack.us/img23/3118/intx.th.jpg [Broken] 2. Relevant equations I'm guessing polar conversion? http://en.wikipedia.org/wiki/Polar_...rting_between_polar_and_Cartesian_coordinates 3. The attempt at a solution I'm having trouble tackling this problem, on one hand Cartesian coordinates seem like a hassle, but turning this into a polar problem will give http://img269.imageshack.us/img269/8738/int2o.th.jpg [Broken] right? This seems like an equally unpleasant integral, what with the cos^3 and all. Am I setting this problem up incorrectly? Can someone tell me the first few steps in doing this problem? I'm fine understanding the problem which the integral applies, just the mechanics on it is getting me.