Calculus
posted by Cynthia .
Which of the following is a step in evaluating.
(Integral) cos^2 5x dx
A. (Integral) 1+cos10x/2 dx
B. (Integral) 1cos10x/2 dx
C. (Integral) 1+cos10x/20 dx
D. (Integral) 1cos10x/20 dx

I'd say A, since cos10x = 2cos^2 5x  1