Example

The line $L$ passes through the points $(4,6)$ and $(-2,5)$. Find the slope of a line parallel to $L$. Find the slope of a line perpendicular to $L$.

Solution

Let's start by finding the slope of the line $L$:

A line parallel to $L$ has the same slope as $L$:

A line perpendicular to $L$ has a slope that is the opposite reciprocal as that of $L$: