Question 999084
Let's call theta, q, for simplicity.
sin^2(q) + cos^4(q) =
sin^2(q) + [cos^2(q)]^2 = 
sin^2(q) + (1 - sin^2(q))^2 =
sin^2(q) + 1 - 2sin^2(q) + sin^4(q) =
sin^4(q) - sin^2(q) + 1