Answer:
21
Step-by-step explanation:
The average rate of change of function f(x) from x = a to x = b is
[tex] \dfrac{f(b) - f(a)}{b - a} [/tex]
Here we have
a = -1
b = 2
f(a) = f(-1) = 1
f(b) = f(2) = 64
[tex] \dfrac{f(b) - f(a)}{b - a} = [/tex]
[tex] = \dfrac{f(2) - f(-1)}{2 - (-1)} = [/tex]
[tex] = \dfrac{64 - 1}{2 + 1} [/tex]
[tex] = \dfrac{63}{3} [/tex]
[tex] = 21 [/tex]
