Answer
See answers below.
Work Step by Step
1. $990^\circ=720^\circ+270^\circ$ is along the $-y$ axis, we have:
2. $sin(990^\circ)=sin270^\circ=-1$
3. $cos(990^\circ)=cos270^\circ=0$
4. $tan(990^\circ)=tan270^\circ$ is undefined.
5. $cot(990^\circ)=cot270^\circ=0$
6. $sec(990^\circ)=\frac{1}{cos270^\circ}$ is undefined.
7. $csc(990^\circ)=\frac{1}{sin270^\circ}=-1$
