Given: r = 4/(-2-6sinθ)
What is the distance between the pole and the directrix?
A. 2
B.2/3
C.3
D.6
This article should make things clear. Your function can be massaged to read
r = -2/(1+3sin?)
http://colalg.math.csusb.edu/~devel/IT/main/m11_conic/src/s08_polar-conics.html