The integral is .

Consider .

Substitute .

Apply derivative on each side with respect to .

.

Substiute 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:.