1. The problem statement, all variables and given/known data ∑ x2n / n! The limits of the sum go from n = 0 to n = infinity 2. Relevant equations 3. The attempt at a solution So I take the limit as n approaches infinity of aa+1 / an. So that gives me: ((x2n+2) * (n!)) / ((x2n) * (n + 1)!) Canceling everything out gives me x2 / (n + 1) The limit as n approaches infinity is x2 1 / (infinity + 1), which is x^2 * 0 So now where do I go from here? x^2 * 0 is 0. So does that mean my interval of convergence is just the point x = 0?