Integration of sin[2x]sin[x] - The Student Room
Hi, This can be done by a bit of manipulation and then can be integrated by sight. There's not really any need for integration by substitution or parts. Recall that, Sin(2a) = 2Sin(a)Cos(a) Int(Sin(2x)Sin(x)) dx = Int(2(Sin(x)^2)Cos(x)) dx You should then...