Step 1:

The trigonometric function is .

Consider .

Properties of inverse trigonometric functions : .

.

Step 2:

Solution :

Step 1:

The trigonometric function is .

Consider .

lies in fourth quadrant.

Construct a triangle:

In fourth quadrant cot function is negative.

Solution:

.

 (b)

The trigonometric function is .

Let .

lies in fourth quadrant.

Construct a triangle:

In fourth quadrant cosec is negative.

.

Solution:

.