1. The problem statement, all variables and given/known data Need to integrate sin(pi*x^3) Got to the end of a long question and this is the final step but I can't seem do it! 2. Relevant equations 3. The attempt at a solution Tried substitution of u = x^3 and said dx = 1/3x^2 du but this doesn't cancel any x variable. I'm guessing I need to use some trig subsitution or something but don't know which?