Question

complete the sentence below. the slope of a vertical line is ___; the slope of a horizontal line is ___. the slope of a vertical line is ; the slope of a horizontal line is undefined 0 m a

Explanation:

Step1: Recall slope formula

The slope formula is $m=\frac{y_2 - y_1}{x_2 - x_1}$. For a vertical line, $x_1=x_2$. So the denominator $x_2 - x_1 = 0$. Division by zero is undefined.

Step2: Analyze horizontal line

For a horizontal line, $y_1=y_2$. Then $m=\frac{y_2 - y_1}{x_2 - x_1}=\frac{0}{x_2 - x_1}=0$.

Answer:

The slope of a vertical line is undefined; the slope of a horizontal line is 0.