Question

6) If a horizontal line passes through (3,9), what is the equation of the line?If a vertical line passes through the point (3,9), what is the equation of the line?

Answer 1

Given

If a horizontal line passes through (3,9), what is the equation of the line

Solution

A horizontal line has a slope(m) of 0 . We can use the point-slope form for a linear equation since we know the slope and the point (3,9)

$\begin{gathered} y-y_1=m(x-x_1) \\ y=9 \\ x=3 \\ y-9=0(x-3) \\ y-9=0 \\ y=9 \end{gathered}$

If a vertical line passes through the point (3,9), what is the equation of the line?

A vertical line is where x is constant. Since it has to pass through the point (3,9) , the equation must be:

$x=3$