1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I have no idea on how to start proving this, but I know the theorem is stating that the integral of a translated periodic function is the same with the integral of the periodic function without translation, is this concept correct? What I am thinking is to use the translation property of integrals to manipulate the equation but so far no success. Any hints or suggestions?