first time working this type of problem and its hard

Question

Solve the given equation. (Enter your answers as a comma-separated list. Let k be any integer. Round terms to three decimal places where appropriate. If there is no solution, enter NO SOLUTION.)

cos² θ − cos θ − 12 = 0

θ =

 

Answer 1

The trigonometric equation is .

Let .

Substitute in the factors.

General solution :

Since , it has no real solutions.

General solution :

Since , it has no real solutions.

No solution for trigonometric equation.