sin2(t) = 1-cos2(t) = 2cos(t) + 2

cos2(t) + 2cos(t) + 1 = 0

(cos(t) + 1)^2 = 0

cos(t) = -1

t = pi

sin^2(θ) = 2cos(θ) + 2

1-cos^2(θ) = 2cos(θ) +2

cos^2(θ)+2cos(θ)+1=0

(cos(θ)+1)(cos(θ)+1)=0

cos(θ)= -1

θ = π