Question

How do you find the average rate of change of `f(x)=x^3-3x+5` over [5,7]?

Answer 1

Just plug the values `5and7` in the function and see what `y` does.

Explanation:

`f(7)=7^3-3*7+5=327`
`f(5)=5^3-3*5+5=115`

Then you divide difference in `f(x)` by difference in `x`:

`(Deltaf(x))/(Deltax)=(327-115)/(7-5)=212/2=106`