Step 1:

The trigonometric function is $\"\"$ .

Consider $\"\"$ , then $\"\"$ .

Definition of inverse tangent function :

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

Draw the right angled triangle :

$\"\"$

From Pythagorean theorem,

The square of the hypotenuse is equal to sum the squares of the other two sides.

$\"\"$

From above figure $\"\"$ .

$\"\"$ .

Substitute $\"\"$ in $\"\"$ .

Properties of inverse trigonometric function: $\"\"$ .

$\"\"$

Solution :

$\"\"$ .