integral 3cos 5x sin 5x dx

jawab
integral
∫ 3 cos 5x sin 5x dx =  3/2 ∫ 2 sin 5x cos 5x
= 3/2 ∫  sin 10 x  dx
= 3/2 (1/10) (- cos 10 x) + c
= - 3/20  cos 10x + c