How do you find the integral of (sin2(6x))(cos2(6x))dx?

1 Answer

You can rewrite this as follows

(sin2(6x))(cos2(6x))dx=(122sin(6x)cos(6x))2dx=14(sin12x)2dx

Remember that

cos2x=cos2xsin2x=12sin2xsin2x=12(1cos2x)

Hence 14(sin212x)dx=18(1cos24x)dx=x81192sin(24x)+c