Question

The slope of the line joining $(1,2)$ and $(1,3)$ is ____

• A. $1$
• B. $0$
• C. $-1$
• D. Not defined

Answer 1

Answer: (D)

Not defined

The slope of a line joining the points $(x_1,y_1)$ and $(x_2,y_2)$ is:

$m=\frac{y_2-y_1}{x_2-x_1}$

Therefore, the slope of the line joining the points $(1,2)$ and $(1,3)$ is:

$m=\frac{3-2}{1-1}=\frac{1}{0}=$ undefined.

Hence, the slope of the line is not defined.