## Precalculus (6th Edition) Blitzer

$\sin (-90^{\circ})=-1 \\ \cos (-90^{\circ})=0$ ; $\tan (-90^{\circ})=$ Not defined and $\csc (-90^{\circ})=-1$; $\sec (-90^{\circ})=$ Not defined ; $\cot (-90^{\circ})=0$
Here, the angle with $(0,-1)$ as a terminal point is: $-90^{\circ}=-270^{\circ}$ The Trigonometric functions are as follows: $\sin (-90^{\circ})=-1 \\ \cos (-90^{\circ})=0$ ; $\tan (-90^{\circ})=$ Not defined and $\csc (-90^{\circ})=-1$; $\sec (-90^{\circ})=$ Not defined ; $\cot (-90^{\circ})=0$