PLEASE HELP Let f(x)=x2+6x+11. What is the average rate of change from x = 5 to x = 8? Enter your answer in the box.

Question

asked Apr 17, 2019 124k views

2 Answers

Ashish Goyal · Answer 1 · 2019-04-23T03:08:43+0000

Answer: The average rate of change is 19.

Step-by-step explanation: The given function is

f(x)=x^2+6x+11.

We are to find the average rate of change from x = 5 to x = 8.

We know that if for a function f(x), f(a) = b and f(c) = d, then the average rate of change from x = a to x = c is given by

A_r=(f(b)-f(a))/(b-a).

For the given function, we have

$f(5)=5^2+6*5+11=25+30+11=66,\\\\f(8)=8^2+6* 8+11=64+48+11=123.$

Therefore, the average rate of change from x = 5 to x = 8 will be

A-r=(f(8)-f(5))/(8-5)=(123-66)/(3)=(57)/(3)=19.

Thus, 19 is the required average rate of change.