average rate of change

Question

givin the function, f(x)=x3-1 find the average rate of change between x=-2 and x=0

Answer 1

f(x) = x^3-1

a = -2, b = 0

f(-2) = (-2)^3-1

= -8-1

= -9

f(0) = (0)^3-1

= -1

Average rate ofchange = (f(b)-f(a))/(b-a)

= [-1-(-9)]/[0-(-2)]

= [-1+9]/2

= 8/2

= 4