sin(−θ)=sinθ\sin (-\theta)=\sin \thetasin(−θ)=sinθ
cos(−θ)=cosθ\cos (-\theta)=\cos \thetacos(−θ)=cosθ
tan(−θ)=tanθ\tan (-\theta)=\tan \thetatan(−θ)=tanθ
cot(−θ)≐cotθ\cot (-\theta) \doteq \cot \thetacot(−θ)≐cotθ