Cambridge O Level Additional Mathematics · Syllabus 4037 · Straight-Line Graphs
Gradient of a Straight Line
What is Gradient of a Straight Line?
The gradient of a straight line is the constant ratio of the change in y to the change in x between any two distinct points on the line, calculated as (y2 - y1) divided by (x2 - x1) with the subtraction taken in the same order in numerator and denominator. It measures how many units the line rises for each unit moved in the positive x direction, so a positive gradient rises from left to right, a negative gradient falls, and a horizontal line has gradient zero. A vertical line has no gradient at all, because the horizontal change between two of its points is zero and division by zero is undefined.
This definition is part of the Straight-Line Graphs chapter in Cambridge O Level Additional Mathematics.