# How do you find the instantaneous rate of change for #f(x)= x^3 -2x# for [0,4]?

##### 1 Answer

Feb 15, 2016

A quick note on terminology: you cannot find the **instantaneous rate of change** over the interval **average rate of change** over the interval, which is given by

#(f(4)-f(0))/(4-0)=(56-0)/4=14#

If you wanted to find the **instantaneous rate of change** at a point