Question

Help! What is the average rate of change of f(x)=x^2+3x+6 over the interval -3 less-than-or-equal-to x less-than-or-equal-to 3?

Answer 1

Answer:

The average rate of change of the function over the interval is 5.

Step-by-step explanation:

Average rate of change of a function:

The average rate of change of a function f(x) over an interval [a,b] is given by:

$A = \frac{f(b)-f(a)}{b-a}$

Interval -3 less-than-or-equal-to x less-than-or-equal-to 3

This means that $a = -3, b = 3$

$f(x) = x^2 + 3x + 6$

So

$f(b) = f(3) = (3)^2 + 3(3) + 6 = 9 + 9 + 6 = 24$

$f(a) = f(-3) = (-3)^2 + 3(-3) + 6 = 9 - 9 + 6 = 6$

Average rate of change

$A = \frac{f(b)-f(a)}{b-a} = \frac{24+6}{3-(-3)} = \frac{30}{6} = 5$

The average rate of change of the function over the interval is 5.