Sum of the root of the equation 2sin2⁡θ+sin2⁡2θ=2;0≤θ≤π/2 is

4sin2⁡θcos2⁡θ=21−sin2⁡θ⇒    2sin2⁡θ−1cos2⁡θ    =0⇒        sin2⁡θ    =1/2or cos2⁡θ    =0 ⇒        θ    =π/4 or    θ    =π/2