Question

Find integral∫cos³x dx) )?​

Answer 1

cos³(x) = cos(x) cos²(x)

… = cos(x) (1 - sin²(x))

Substitute u = sin(x) and du = cos(x) dx. Then in the integral, you get

∫ cos³(x) dx = ∫ (1 - u ²) du

… = u - 1/3 u ³ + C

… = sin(x) - 1/3 sin³(x) + C

Answer 2

sin(x)−1/3(sin3(x))+C

Explanation:

use u substitution method to integrate