Question

What is the average rate of change of the function f(x) = 4x – 2 over the interval x = –1 and x = 2?

Answer 1

Answer:

$4$

Step-by-step explanation:

Given: $f(x)=4x-2$

To find:  average rate of change of the function $f(x)=4x-2$ over the interval $x=-1$ and $x=2$

Solution:

Take $a=-1,\,b=2$

Find $f(a),\,f(b)$

$f(a)=f(-1)\\=4(-1)-2\\=-4-2\\=-6\\\\f(b)=f(2)\\=4(2)-2\\=8-2\\=6$

Average rate of change of the function $=\frac{f(b)-f(a)}{b-a}$

$=\frac{f(2)-f(-1)}{2-(-1)}\\\\=\frac{6-(-6)}{3} \\\\=\frac{12}{3}\\\\=4$