Question

The graph of a function g is shown below. Use the graph of the function to find its average rate of change from x = 7 to x = 9 . Simplify your answer as much as possible.

Answer 1

SOLUTION

The formula for average rate of change is given as

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

The given interval is x=7 to x=9

Hence the average rate of change becomes

$A=\frac{f(9)-f(7)}{9-7}$

From the graph,

When x =7, f(7)=-7

When x=9, f(9)= -1

The average rate of change is

$A=\frac{-1-(-7)}{9-7}$

Solve for A

$\begin{gathered} A=\frac{-1+7}{2} \\ A=\frac{6}{2} \\ A=3 \end{gathered}$

Therefore the average rate of change is 3