CPM Homework Help : INT3 Problem 12-13

If $\pi<θ<\frac{3\pi}{2}$ , what is the sign of each expression?

Hint 1 (all):

You are in the third quadrant.

Hint 2 (all):

What are the signs of $x$ and $y$ in the third quadrant?

$\operatorname { cos } ( \theta )$
Hint (b):
Use the same method as part (a). It might also help to think about how the $\sin(x)$ and $\cos(x)$ graphs relate to each other.

$\operatorname { tan } ( \theta )$
Hint (c):
Use the same method as part (a).
Answer (c):
Negative

$\frac { 1 } { \operatorname { cos } ( \theta ) }$
Hint (d):
Does taking the reciprocal of something change its sign?