Step 1:

\

The expression is $\"\"$ .

\

Using sum and difference formulas

\

$\"\"$ .

\

The expression can be written as

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

$\"\"$

\

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

Solution:

\

$\"\"$

\

\

\