How to solve ?

Question

1.

2.

 

Answer 1

(1)

Step 1:

The trigonometric equation is .

.

Squaring on each side.

Pythagorean identity: .

and

and

and

General solution of is .

General solution of are and .

General solution of is .

Thus, Option (c) is correct.

Solution:

.

Option (c) is correct.

Answer 2

(2)

Step 1:

The trigonometric equation is .

.

Squaring on each side.

Pythagorean identity: .

General solution of are  and .

General solution of is .

Thus, Option (d) is correct.

Solution:

General solution of is .

Option (d) is correct.