1. The problem statement, all variables and given/known data Please see attached image. From the given information, I am having trouble deriving the left and right hand limits, I just can't figure out what these are... http://img176.imageshack.us/img176/9334/fstih3.png [Broken] 2. Relevant equations None needed. 3. The attempt at a solution In the solution, t is chosen as pi, which I understand. But I just can't figure out how these left and right hand limits are found. Are these limits somehow derived from limits of integration? Here is the solution. http://img176.imageshack.us/img176/2899/fst2yg0.png [Broken] Any help will be appreciated.