Question

Verify the identity.

Answer 1

Step 1:

(a)

The identity is for .

Consider

Definition of inverse trigonometric function: then

Substitute .

Step 2:

(b)

The function is for .

Consider

Take tangent of each side.

Sum formula of tangent function: .

Property of inverse trigonometric function:

.

Solution:

(a) .

(b) .