The integral is .

Consider .

Substitute .

Apply derivative on each side with respect to .

.

Substitute the corresponding values in the integral.

Apply trigonometric identity: .

Trigonometric identity: .

Apply general power rule of integration: .

.

If then .

(a)

Apply integration limits.

.

(b)

Apply trigonometric limits in equation .

.

If then .

If then .

.

(a) By the integration limits :.

(b) By the limits obtained by the trigonometric substitution:.