A point in a coordinate plane has coordinates (x, y).
From the graph, point A is at (2,1) and point B is at (4,2).
The vertical change corresponds to the change in the y-coordinate. Point A is at 1, and point B is at 2, therefore, the change is 2 - 1 = 1.
The horizontal change corresponds to the change in the x - coordinate. Point A is at 2 while point B is at 4, therefore, the change is 4 - 2 = 2.
The rate of change is written as vertical change over horizontal change. Thus, the rate of change is 1/2 or 0.5.
