Given
A line that is parallel to the x-axis and is perpendicular to the y-axis, and has a slope of 0
To find the equation of the line.
The equation of the line parallel to x axis is given by,

The equation of the line perpendicular to y axis is,

Hence, the equation of the given line is of the form.

Since slope is 0.
Then,

Therefore the equation is y=b.