Integral 2 sin 4x cos 2x dx Integral 4 sin 5x sin x dx

∫2 sin 4x cos 2x dx
= 2 ∫ 2 sin 2x cos 2x cos 2x dx
= -2 ∫cos² 2x dcos 2x
= -(2/3) cos³ 2x + C