Question

8 which of the following is not true about vertical lines? a vertical lines are perpendicular to the x - axis. b vertical lines have undefined slope. c vertical lines have equations of the form y = b. d vertical lines are parallel to the y - axis.

Explanation:

1. Recall properties of vertical lines:

• Vertical lines are perpendicular to the x - axis and parallel to the y - axis. Their slope is undefined because for two points \((x_1,y_1)\) and \((x_2,y_2)\) on a vertical line \(x_1 = x_2\), and slope \(m=\frac{y_2 - y_1}{x_2 - x_1}\), the denominator is 0.
• The equation of a vertical line is of the form \(x = a\) (where \(a\) is a constant), while the equation \(y = b\) represents a horizontal line.

Answer:

C. Vertical lines have equations of the form \(y = b\).