# How to find instantaneous rate of change for #x^3 +2x^2 + x# at x from 1 to 2?

##### 1 Answer

Jul 20, 2018

The instantaneous rate of change is the same as taking the derivative. This is defined at a point.

We can easily find that function via power rule:

I hope it is clear here that the concept of "instantaneous rate of change" from one point to another doesn't make any sense. However, you can think about the *average* rate of change very easily. We just do that in the way we'd think: the change in y divided by the change in x. This gives the following: