1. The problem statement, all variables and given/known data This ( http://www.wolframalpha.com/input/?i=integrate+cos^6+(x)+dx+from+0+to+pi/2 ) is the integral I am trying to evaluate.: int cos^6 (x) dx from 0 to pi/2 2. Relevant equations (1 + cos(2x))/2 = cos^2 (x) (1 – cos(2x))/2 = sin^2 (x) sin^2 (x) + cos^2 (x) = 1 Variable substitution 3. The attempt at a solution My (typed-up) work is attached as MyWork.jpg. I would greatly appreciate it if someone could tell me where I went wrong in my work!