Answer
$m=\text{undefined}$
Work Step by Step
Using $m=\dfrac{y_1-y_2}{x_1-x_2}$, the slope of the line determined by the given points, $(
-2,4
) \text{ and } (
-2,-6
),$ is
\begin{array}{l}\require{cancel}
m=\dfrac{4-(-6)}{-2-(-2)}
\\\\
m=\dfrac{4+6}{-2+2}
\\\\
m=\dfrac{10}{0}
\\\\
m=\text{undefined}
.\end{array}