$$\begin{eqnarray*} \sin\left(\frac{\pi}{2}-\theta\right) & = & \cos\theta\\ \cos\left(\frac{\pi}{2}-\theta\right) & = & \sin\theta\\ \tan\left(\frac{\pi}{2}-\theta\right) & = & \cot\theta\\ \cot\left(\frac{\pi}{2}-\theta\right) & = & \tan\theta\\ \csc\left(\frac{\pi}{2}-\theta\right) & = & \sec\theta\\ \sec\left(\frac{\pi}{2}-\theta\right) & = & \csc\theta \end{eqnarray*}$$