Respuesta :

sstarica the question issin4 3x dx
substitute (cos x)^2 = 1 - (sin x)^2

∫(1−cos^2(3x))^2 dx = ∫(1−2cos^2u + cos^2u) du

1/15 ∫ 5(3)sin^4 (3x) dx

-cos^5 (3x)/15 + C