1. The problem statement, all variables and given/known data From angles pi minus theta1 to pi plus theta1, what is the integral of cosine of 2 theta times d theta? 2. Relevant equations 3. The attempt at a solution When I evaluate this definite integral from pi minus theta1 to pi plus theta1, I get positive one half sine of 2 theta1. It should be NEGATIVE one half sine of 2 theta1. Is 2pi + 2theta1 and 2pi - 2theta1 somehow wrong????