The functions are , and where .

(1) Find :

.

Pythagorean identity: .

, lies in tyhe second quadrant.

Therefore, is negative.

.

Substitue in the above expression.

.

.

Substitue   and in the above expression.

Step 2:

(2)

Find .

where .

Pythagorean identity: .

.

As , then lies in fourth quadrant.

Thus, is negative.

Substitue in the above expression.

.

(3)

Step 3:

Find .

Double angle formula; .

Substitue   and in the above expression.

(4)

Find .

where .

Double angle formula; .

Substitue in the above expression.

.

Pythagorean identity: .

.

As , then lies in fourth quadrant.

Thus, is negative.

.