Question

Find the average rate of change for f(x) = x2 + 9x + 18 from x = 10 to x = 20.

Answer 1

Answer:

The average rate of change for f(x) from x = 10 to x = 20 is 39.

Step-by-step explanation:

The given function is

$f(x)=x^2+9x+18$

$f(10)=(10)^2+9(10)+18=208$

$f(20)=(20)^2+9(20)+18=598$

The formula for average rate of change for a function is

$m=\frac{f(x_2)-f(x_1)}{x_2-x_1}$

We have to find the average rate of change for f(x) from x = 10 to x = 20.

$m=\frac{f(20)-f(10)}{20-10}$

$m=\frac{598-208}{10}$

$m=\frac{390}{10}$

$m=39$

Therefore the average rate of change for f(x) from x = 10 to x = 20 is 39.

Answer 2

First, plug x=10 and x=20 into the formula: 
10^2+90+18
190+18
208

20^2+180+18
400+198
598

598-208=390

390/10 = 39

The average rate of change is 39