Integral of sin^2(x)

Ok so I am a little disappointed to hear that people are using the chain rule in integration. We have NEVER used the chain rule in integration. Your options are substitution and that is all. You can't substitute in this problem because the derivative of sin(x) is not in the integral. However, it is a trig function so you can use identities to manipulate it. For lack of being able to type mathematically here is a link to it already done.

http://wiki.answers.com/Q/Integral_of_sin_squared_x