Question: how to find the equation of a line with zero slope?
Answer: Horizontal and Vertical Lines and Their Slopes.
Recall the slope of a line is a numerical measure of the steepness of the line. We can find a line's slope using the slope formula or the slope-intercept form. • ... 
, = 1,3 and.
, = 4,3, we get.
= − − ... 
3 − 3. 4 − 1.
= = 0. ... 
The slope of any horizontal line is zero, 0.