The standard equation of parabola:
(y-k)²=4p(x-h), with:
a) vertex = (h,k)
b) focus = (h+p, k)
c) directrix = (x=h-p)
Since this parabola has a vertex at (0,0) that means h=k=0
Hence the equation becomes: y²=4px, let's calculate p:
focus is given (-9,0) Remember h+p = -9 & since h=0, then p= -9
===> y²= - 36x
