Question

How do you find the average rate of change of `f(x)=-5x+2` from [2,4]?

Answer 1

`-5`

Explanation:

`"the average rate of change of f(x) over an interval "[a,b]`
`"is the slope of the "color(blue)"secant line"" connecting the 2 points"`
`(a,f(a))" and "(b,f(b))`

`• " average rate of change "=(f(b)-f(a))/(b-a)`

`f(b)=f(4)=-20+2=-18`

`f(a)=f(2)=-10+2=-8`

`"average rate of change "=(-18-(-8))/(4-2)`

`color(white)("average rate of change ")=-10/2=-5`