1−sinθcosθ\frac{1-\sin \theta}{\cos \theta}cosθ1−sinθ
cosθ1−sinθ\frac{\cos \theta}{1-\sin \theta}1−sinθcosθ
1+cosθsinθ\frac{1+\cos \theta}{\sin \theta}sinθ1+cosθ
sinθ1+cosθ\frac{\sin \theta}{1+\cos \theta}1+cosθsinθ