Find the equation of the parabola with focus at 0 2 and vert
     Find the equation of the parabola with focus at (0, 2) and vertex at (0, 0)  Transform the polar equation into rectangular form.  r = -4 cos theta 
  
  Solution
Focus (0,2) and vertex(0,0)
The parabola have the following form
y=(1/4p)(x-h)2+k
Here vertex (h,k) is (0,0)
focii (h,k+p) which is (0,2)
Therefore p=2
Hence the required equation is
y=(1/8)x2 = x2/8

