1. The problem statement, all variables and given/known data Find a power series representation for the function and determine the radius of convergence. heres the problem: http://img301.imageshack.us/img301/4514/30437250jj2.png [Broken] 2. Relevant equations 3. The attempt at a solution i believe the derivative of arctant = 1/(1+t^2) thats all i know for now, whats next?