Please Help ; what does the average rate of change tell you about the function on the interval ?
If you have the two points at the ends of the interval [a,b], then no matter how f(x) twists and turns in the interval, the average rate of change is the slope of the line joining (a,f(a)) and (b,f(b)). That is,
(f(b)-f(a))/(b-a)