`x^2=-36y` Graph the equation. Identify the focus, directrix, and axis of symmetry of the parabola.
Let `x^2=4py` be equation of parabola. Then equation of directrix is `y=-p` coordinates of focus are `(0,p)` and axis of symmetry is `y`-axis.
In this case the equation of parabola is
Using the facts stated above we can write equation of directrix and coordinates of focus.
Directrix is line with equation `y=9,` focus is the point with coordinates `(0,-9)` and axis of symmetry is `y`-axis.