Simplify: sin4(θ)−cos4(θ)\sin^4(\theta) - \cos^4(\theta)sin4(θ)−cos4(θ).
111
sin2(θ)−cos2(θ)\sin^2(\theta) - \cos^2(\theta)sin2(θ)−cos2(θ)
2sin2(θ)−12\sin^2(\theta) - 12sin2(θ)−1
sin2(θ)+cos2(θ)\sin^2(\theta) + \cos^2(\theta)sin2(θ)+cos2(θ)