We notice that the gradient of a curve changes at every point on the curve, therefore we need to work with the average gradient.
The average gradient between any two points on a curve is the gradient of the straight line passing through the two points.
In other words, average gradient is the same as the rate of change.
Formula to calculate average gradient.
Suppose you have a curve and your asked to find the average gradient of a point (0,2) , ( 5,4).
Therefore, the average gradient is 0.4.