Question

which describes the slope of the given line?
negative
positive
undefined
zero

Explanation:

Step1: Recall slope formula

The slope formula is $m=\frac{y_2 - y_1}{x_2 - x_1}$. For a vertical line, $x_1=x_2$.

Step2: Analyze the denominator

When $x_1 = x_2$, the denominator $x_2 - x_1=0$ in the slope - formula. Division by zero is undefined.

Answer:

Undefined