1. The problem statement, all variables and given/known data Evaluate the integral ∫1/(x^4)(sqrt(a^(2) - x^(2)) 2. Relevant equations u= dx/sqrt(a^2-x^2) du= arcsin(x/a)dx 3. The attempt at a solution Am I even doing this right? And if so, how would I express 1/x^4 in terms of u? Have I taken the right u-substitution? Thanks.