just started learning this and im lost

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.)

cos θ(2 cos θ + 1) = 0

θ =

 

Answer 1

The trigonometric equation is .

General solution :

If , then , where is an integer.

General solution :

If , then , where is an integer.

The general solution is .