Question

Evaluate ∫ sin 2 x sin 3 x d x ?

Answer 1

Answer:

(1/2) sin x - (1/10) sin 5 x + c

Step-by-step explanation:

∫ sin 2 x sin 3 x d x

= (1/2) ∫ 2 sin 2 x sin 3 x d x

= (1/2) ∫ (cos x - cos 5 x) d x

[since, 2 sin a sin b = cos (a-b) - cos (a+b)]

= (1/2) sin x - (1/10) sin 5 x + c

where, c is integration constant.