Please see attached Mathematica file.
The calculated answer when I perform the calculations manually is 9, which is substantially different than the answer that I am getting from Mathmatica.
I even broke the double integral down into two single integrals, but ended up with the same answer. For whatever the reason, Mathematica doesn't seem to want to integrate the Cos(Theta) in the 2nd part of the integral even though I am integrating with respect to Theta.
I am using Mathematica 9 (Home Edition) Version 9.0.1.0
The problem is something that I am doing incorrectly, but cannot figure it out.
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