1. The problem statement, all variables and given/known data (dont know how to make the integral sign so bare with me please) i will use | to signify the integral sign: here is my problem: |(sinx)(cos)dx 2. Relevant equations n/a 3. The attempt at a solution ok this is what i did: first i changed it to (1/2)sin2x because sin2x=2sinxcosx so now i have: |(1/2)sin2xdx then i said u = 2x and du=2dx so now i have: |(1/4)sinudu which is: (1/4)(-cos u) + C which is: (1/4)(-cos2x) + C where is my error? also, can someone give me a brief overview of the best strategy to figure out what type of integration to use? what do you look for to know when to use trig substituion, integration by parts, u-substitution, etc... ie, how do you know? thanks.