[tex]\bf \textit{Cofunction Identities}
\\\\
sin\left(\frac{\pi}{2}-\theta\right)=cos(\theta)
\qquad
cos\left(\frac{\pi}{2}-\theta\right)=sin(\theta)
\\\\\\
tan\left(\frac{\pi}{2}-\theta\right)=cot(\theta)\qquad
cot\left(\frac{\pi}{2}-\theta\right)=tan(\theta)
\\\\\\
sec\left(\frac{\pi}{2}-\theta\right)=csc(\theta)\qquad
csc\left(\frac{\pi}{2}-\theta\right)=sec(\theta)[/tex]
therefore, sin(x) = cos(90° - x).
