$\"\"$

The integral is $\"\"$ .

From the trignometric subustitution, subustiute $\"\"$ and $\"\"$ .

$\"\"$ limits change from $\"\"$

Limits of integration will change from $\"\"$ to $\"\"$ to $\"\"$ .

$\"\"$ .

From the pythagorean identity : $\"\"$ .

$\"\"$

From the trignometric identity : $\"\"$ .

$\"\"$

Apply the integration :

$\"\"$

$\"\"$ .