1. The problem statement, all variables and given/known data Integral x^3sqrt(4x^2 -x^4) dx 2. Relevant equations Maybe something from a table 3. The attempt at a solution I pulled the x^2 our from under the square root. ∫ x^4 (sqrt(4-x^2)) dx I'm not sure how I can do this one. Maybe it can fit the forum ∫ usinu du ?