# How do you find the equation of the parabola vertex at the origin and the directrix at x=7?

##### 1 Answer

Jan 10, 2016

#### Answer:

With a **vertex** **directrix** **opens to the left** and will be of the form

#### Explanation:

The absolute **distance** between the directrix and vertex

So, the coefficient

The sign of the coefficient must be **NEGATIVE** because the parabola opens to the left.

**vertex**

Finally, substitute the values into the equation ...

**Equation** :

hope that helped