Question

If a line is​ horizontal, then its slope is​ ____. If a line is​ vertical, then its slope is​ ____.

Answer 1

If a line is horizontal, then its slope is **0**. This is because there is no change in the y-coordinate as the x-coordinate changes.

If a line is vertical, then its slope is **undefined**. This occurs because the change in the x-coordinate is zero, which would result in division by zero when calculating slope (slope = change in y / change in x).