Question

Question 6 Find the slope of the line passing through the points (11,-5) and (11,6)

Answer 1

There are two ways to approach this.

Option #1:

Use the slope formula $m = \dfrac{y_2-y_1}{x_2-x_1}$.

    $m= \dfrac{6-(-5)}{11-11} = \dfrac{11}{0}$

That value is undefined, so the slope is undefined.

Option #2:

Because the two points have the same x-value, they will be vertically above/below one another.  This means your line is a vertical line and the slope of a vertical line is undefined.

Either way, your slope is undefined.