Question

What is the slope of each of these three graphs?

Answer 1

[5] No slope (or a slope of 0)

      There is no incline or decline to the line, so there is no slope.

[6] 1

      We can use "rise over run" since we have clear points on the graph. See attached.

[7] Undefined slope

      This slope of this line is undefined. The formula for slope is $\frac{\text{change in y}}{\text{change in x}}$ which becomes $\frac{0}{0}$ in a case like this. You cannot divide by 0, giving a slope of undefined.