Trigonometry
Write the following expression in terms of θ\thetaθ only. Use the identity for the cosine of a difference.
cos(180∘−θ)\cos\left(180^{\circ}-\theta\right)cos(180∘−θ)
−sinθ-\sin\theta−sinθ
2sinθ2\sin\theta2sinθ
−cosθ-\cos\theta−cosθ
sinθ+2cosθ\sin\theta+2\cos\thetasinθ+2cosθ