1. The problem statement, all variables and given/known data I was given this problem as homework and managed to find the solution online, but I don't fully understand it. My only question, and the reason I was getting this problem wrong, is because I wasn't realizing that the functions evaluated from -∞ to +∞ were vanishing. Is this a concept from calculus I'm not understanding or is this related somehow to a QM postulate or something? Thanks!