Gradient is the measure of a line’s steepness (slope).
The gradient of a line describes the change in y values as the x value increases by 1.
The size of the gradient tells us how steep a line is.
The sign ( + or – ) tells us whether the line slopes up or down.
Gradient = vertical rise / horizontal run
m = rise / run
= change in y value / change in x value
= y2 – y1 / x2 – x1
The gradient of any horizontal line is zero.
The gradient of any vertical line is undefined.