Question
1. Find the average rate of change of f(x)=x^3-9x+9:
a) from -8 to -2
b) from -1 to 1
c) from 1 to 4
a) what is averge rate of change of f (x) =x^3-9x+9 from -8 to -2?
a) from -8 to -2
b) from -1 to 1
c) from 1 to 4
a) what is averge rate of change of f (x) =x^3-9x+9 from -8 to -2?
Answers
Reiny
I will do a) , you do the others in the same way
f(x) = x^3 - 9x + 9
f(-2) = -8 + 18 + 9 = 19
f(-8) = -512 + 72 + 9 = -431
avg rate of change
= (f(-2) - f(-8) )/(-2 - (-8))
= (19 - (-431))/(-2 - (-8))
=450/6
= 75
f(x) = x^3 - 9x + 9
f(-2) = -8 + 18 + 9 = 19
f(-8) = -512 + 72 + 9 = -431
avg rate of change
= (f(-2) - f(-8) )/(-2 - (-8))
= (19 - (-431))/(-2 - (-8))
=450/6
= 75