Question

Find the equation of a line which is parallel to $x$-axis and has $y$-intercept as -3.

• A. $x=-3$
• B. $y=-3$
• C. $y=-3x$
• D. $x=-3y$

Answer 1

The correct option is B $y=-3$

As we know,
Slope of $x$-axis is zero.
Hence, The line parallel to the $x$ axis is also zero.

Let slope intercept form of equation of a line.
$y=mx+c$
$\Rightarrow$ $m$ is the slope of the line
$\Rightarrow$ $c$ is the $y-$intercept of the line.

Given, $c=-4$
$m=0$

Substitute c = -4 and m = 0 in the slope-intercept form
$y=mx+c$
$y=0\times x+(-3)$
$y=-3$

Line $y=-3$ is represented on the cartesian plane.