$\"\"$

The expression is $\"\"$ .

Rewrite the expression as $\"\"$

Apply sum formula : $\"\"$ .

$\"\"$

Substitute the values of $\"\"$ .

$\"\"$

$\"\"$ \ \ Multiply the numerator and the denominator by $\"\"$ .

$\"\"$

$\"\"$ .

$\"\"$

The value of the expression is $\"\"$ .