# How do you find the equation of the line that goes through P(3, -4), slope is undefined?

Aug 18, 2017

See a solution process below:

#### Explanation:

A line is a vertical line when the slope of the line is undefined.

This means for each and every value of $y$, the $x$ value is the same.

So, given the point $P \left(3 , - 4\right)$ we know the $x$ value is $3$.

Therefore, we can plug any value in for $y$ and $x$ will always be $- 8$.

Therefore the equation for this line is:

$x = 3$

Regardless of the value of $y$, $x$ will always be $3$