Hi, I'm having trouble with this problem. I'm supposed to find the trig functions. If I can have some help on part a I think I can do the rest on my own.

1. Suppose that cosθ =−1/3, where π <θ < 3π/2.

Find and simplify the following. Draw a picture to help explain your answer.

tanθ

a)

I was able to draw a picture and determine that the point lies in quadrant 3. Do I need to use a pythagorean equation to find sinθ and then use that to find tanθ?