1. The problem statement, all variables and given/known data ∫cos(x)sin^6(x)*dx 2. Relevant equations 3. The attempt at a solution u=sin(x) then du should be -cos(x) according to the integral tables? -∫u^6*du = -u^7/7 -sin^7(x)/7+c yet my book and calculator tell me the answer is positive. How??????