Please explain how you get the answer.
1. Tan(-20°)= ?

For example: Tan(-20°)=?
Has 4 choices which are:
-tan 20°
tan 20°
tan (-160°)
-tan 160°


2.cos(-49°)=?

3.sin(-150°)=?

4.sec(-121°)=?

5.cos(-170°)=?

6.tan(-163°)=?

7.csc(-112°)?

8.sin(-295°)=?

9.cos(-15°)=?

10. Tan(-216°)=?