1. The problem statement, all variables and given/known data I am looking for help with part (d) of this question 2. Relevant equations 3. The attempt at a solution I have attempted going through the integral taking L = 4 and t0 = -2. I was able to solve for a0 but I keep having the integrate by parts on this one. I've tried it out twice and messed up. Any help would be appreciated.