How do you find the equation of the parabola with directrix y=3 and focus (-3,-2)?
The axis of the parabola is perpendicular to the directrix through the focus S. So, its equation is x =
The vertex V is on the axis, midway in-between focus S and directrix.
So, V is at
The size parameter a = VS =
Now, the equation is as given in the answer,
Note that 4a =