周期性　n は整数
\(\sin(\theta+2n\pi)=\sin\theta\)
\(\cos(\theta+2n\pi)=\cos\theta\)
\(\tan(\theta+n\pi)=\tan\theta\)

補角の公式　対称性
\(\sin(\pi-\theta)=\sin\theta\)
\(\cos(\pi-\theta)=-\cos\theta\)
\(\tan(\pi-\theta)=-\tan\theta\)

余角の公式　対称性
\(\sin\left(\dfrac{\pi}{2}-\theta\right)=\cos\theta\)
\(\cos\left(\dfrac{\pi}{2}-\theta\right)=\sin\theta\)
\(\tan\left(\dfrac{\pi}{2}-\theta\right)=\dfrac{1}{\tan\theta}\)