## Precalculus (6th Edition) Blitzer

$$\sin \theta, \\ \tan \theta, \\ \sec \theta$$
Please note that the value of a trigonometric function of $\theta$ is equal to the cofunction of the complement of $\theta$. So we have$$\sin \theta = \cos (90^{\circ} - \theta ), \\ \tan \theta = \cot (90^{\circ} - \theta ), \\ \sec \theta = \csc (90^{\circ} - \theta ).$$