1. The problem statement, all variables and given/known data What is the definite integral of 1/(36+x^2) with bounds [0, 6]? I've only been taught U substitution to handle problems like these. I let u = 36+x^2 and du=2xdx but I am stuck and don't know what to do. Te answer is pi/24 but I don't know how to obtain it. Is there a better u to choose? if so, what?