Solve the equation 8 sin theta cos 2 theta What is the sol

Solve the equation. 8 - sin theta = cos (2 theta) What is the solution in the interval 0 lessthanorequalto theta

-sin theta=cos(2theta)

-sin theta=1-2sin²theta

2sin²theta-sin theta-1=0

2sin²theta-2sin ttheta+sin theta-1=0

2sin theta(sin theta -1)-1(sin theta-1)=0

(2sin theta-1)(sin theta-1)=0

sin theta=1/2 , sin theta=1

theta=pi/6,5pi/6, theta=pi/2