Hi Dojo,

Here's one way to find it.

Your parabola will be in the form: since it has a vertical directrex.

The dirctrex equation is

So, we have [1]

The focus is at

and

So, we have [2]

Solve the system of equations [1] and [2] for h and a.

[1]

[2]

Substituting into [1],

Now, you will have everything you need to create your equation.