∫ sin 4x cos 7x dx
We know 2sinAcosB = sin(A + B) + sin(A – B)
∴ sin4xcos7x =
We know sin( – θ) = – sinθ
∴ sin( – 3x) = – sin3x
∴ The above equation becomes
⇒
We know
⇒ + c