# How do you find the equation of the parabola whose focus is at (3, 3) and whose directrix is at x = 7?

##### 1 Answer

Mar 13, 2018

#### Explanation:

A quadratic relation (or function) can be in the form:

Since our diretrix is a vertical line, our parabola is horizontal.

We, therefore, use the form

In this form, the focus is at

Using our information, the focus is at

Therefore,

We add the second and the third equations to get:

Let's plug in what we know: