$\"\"$

The trigonometric identity is $\"\"$ .

Prove $\"\"$ .

Consider $\"\"$ .

Substitute $\"\"$ in the above expression.

$\"\"$

Apply Trignometric formula: $\"\"$ .

$\"\"$

Reciprocal of trignometric function: $\"\"$ and $\"\"$ .

$\"\"$

Hale angle identity : $\"\"$

$\"\"$

$\"\"$ . \ \

Therefore if $\"\"$ then $\"\"$ . \ \

$\"\"$

If $\"\"$ then $\"\"$ . \ \