Find the exact solutions over the indicated intervals a 2 co

Find the exact solutions over the indicated intervals. a) 2 cos^2 theta + sin 2theta = 0, 0degree lessthanorequalto theta lessthanorequalto 360degree

2cos^2x + sin2x = 0

=> 2cos^2x + 2sinx.cosx = 0

=> cosx(cosx + sinx) = 0

=> cosx=0 or cosx=-sinx

=> cosx=0 or tanx=-1

=> x=(2n+1)/2 or x=n-/4

Between [0,360], x= 90°,135°,270°,315°.