1. The problem statement, all variables and given/known data 2. Relevant equations http://postimage.org/] [/PLAIN] [Broken] 20mb image hosting 3. The attempt at a solution Found width of that rectangle. Multiply times delta h. My question is, why is the integral from -3 to 3? When I try to evaluate the integral by going h(3) - h(-3) I get 0-0. If you use 3 or -3 for h you get 0. I don't understand how to evaluate this integral?