1. The problem statement, all variables and given/known data 1/(u^2+4) 2. Relevant equations 3. The attempt at a solution I know that 1/(x^2+1) is the derivative of the inverse tangent function, and that is proved by using tany = x, derivative of both sides with secx=(1+tan^2x) and tan^2x = x^2. I don't know how to use the proof of the inverse tangent derivative to calculate the integral of 1/(u^2+4). Am I approaching this in an incorrect way?