Question

Calculate the average rate of change for f(x) = 3x + 4, from x=5 to x=5+h.

Answer 1

The average rate of change for a given function from point a to point b is computed as follows:

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

In this case:

• f(x) = 3x + 4

,

• b = 5 + h

,

• a = 5

$\frac{3(5+h)+4\text{ - ( 3(5) + 4)}}{5+h\text{ - 5}}=\frac{15+3h+4\text{ - 15 - 4}}{h}=\frac{3h}{h}=\text{ 3}$