CPM Homework Help : CCA2 Problem 12-15

If $π < θ <\frac { 3 \pi } { 2 }$ , what must be true about the sign of:

Hint 1(all):

Graph each function using the input bar below or on your graphing calculator. What do you observe about the $y$ -values when $θ$ is between $π$ and ^3π/₂?

Hint 2(all):

When graphing using the input bar, sin( $θ$ ) is equivalent to sin( $x$ ).

sin(θ)
Answer (a):
The $y$ -values are negative.
cos(θ)
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.
tan(θ)
Hint (c):
Use the same method as part (a).
Answer (c):
positive
$\frac { 1 } { \operatorname { cos } ( \theta ) }$
Hint (d):
Does taking the reciprocal of something change its sign?