Question 712342
3 - sin theta = cos(2 theta)
3-sinx=cos2x
3-sinx=1-2sin^2x
sin^2x-sinx+2=0
(sinx-1)(sinx+2)=0
sinx+2=0
sinx=-2 (reject, (-1 ≤ x ≤ 1))
sinx-1=0
sinx=1
x=π/2