integral sin 2x sin x dx

Integral Substitusi Fungsi Trigonometri.

∫ sin 2x sin x dx
= ∫ (2 sin x cos x) sin x dx
= 2 ∫ sin² x cos x dx
u = sin x
du / dx = cos x
= 2 ∫ u² cos x du / cos x
= 2 (1/3 u³) + C
= 2/3 sin³ x + C