Question

How do you find the average rate of change of `f(x)=2x^2+2` from 4 to 6?

Answer 1

`20` (details in "Explanation")

Explanation:

For a function `f(x)` the rate of change, in a close interval `a to b`, is given by

`(f(b)-f(a))/(b-a)`

For
`f(x) = 2x^2+2`
The required rate of change (with `a=4 and b=6`) is

`([2*6^2+2]-[2*4^2+2])/(6-4)`
`(74-34)/2=40/2=20`