Find the average rate of change of

Solution:
The average rate of change is given as:
[tex]Rate\ of\ change = \frac{f(b) - f(a)}{b-a}[/tex]
Given that,
[tex]f(x) = \sqrt{x+6}[/tex]
Given interval is [4, 9]
a = 4
b = 9
Find f(b)
[tex]f(9) = \sqrt{9+6}\\\\f(9) = \sqrt{15}\\\\f(9) = 3.872[/tex]
Find f(a)
[tex]f(4) = \sqrt{4+6}\\\\f(4) = \sqrt{10}\\\\f(4) = 3.162[/tex]
Therefore, average rate of change is given as:
[tex]Rate\ of\ change = \frac{3.872-3.162}{9-4}\\\\Rate\ of\ change = \frac{0.71}{5}\\\\Rate\ of\ change = 0.142 \approx 0.14[/tex]
Thus average rate of change is 0.14