Question

Which graph is parallel to $x-$axis?

Answer 1

Explaining the graph parallel to $x-$axis

The slope of the $x-$axis is $0$ and the origin lies on the $x-$axis

Hence, the equation of the $x-$axis is

$y-0=0\left(x-0\right)$

$\Rightarrow$ $y=0$

As parallel lines have equal slope, all lines having the equation of the type

$y=k$ will have slope $0$.

Hence all lines having equation of the type $y=k$ are parallel to the $x-$axis