# How do you find the slope of a line perpendicular to y=2x?

Jun 18, 2015

All lines perpendicular to $y = 2 x$ have a slope of $\left(- \frac{1}{2}\right)$

#### Explanation:

$y = 2 x$ has a slope of $2$
$\textcolor{w h i t e}{\text{XXXX}}$this follows from the observation that
$\textcolor{w h i t e}{\text{XXXX}}$$\textcolor{w h i t e}{\text{XXXX}}$$y = 2 x$
$\textcolor{w h i t e}{\text{XXXX}}$ is of the slope-intercept form with a slope of $2$
$\textcolor{w h i t e}{\text{XXXX}}$(and a y-intercept of $0$).

If a line has a slope of $m$ then
all lines parallel to it have a slope of $- \frac{1}{m}$.