algebra 2 problem

Question

Find the average rate of change of f(x) = x3 -9x +6
a. From-8 to -5
b. From -1 to 1
c. From 1 to 2
what is the average rate of change of f (x) =x3 + 9x + 6 from -8 to -5

Answer 1

f(x) = x³-9x+6

 

The formula for Rate of change = [f(b) - f(a)]/(b - a)  from a to b.

 

1) For -8 to -5

    a=-8, b=-5

    f(a) = (-8)³-9(-8)+6 = -512+72+6=-434

    f(b) = (-5)³-9(-5)+6 =-125+45+6=-74

 

   [f(b)-f(a)]/(b-a) = (-434-(-74))/((-5-(-8)) = -360/3= -120

 

Try the others yourself with the above example.

 

 

 

 

 

Answer 2

Average rate of change is represented by the formula

 

Rate of change = (f(b) - f(a)) / (b - a)        from a to b.

 

 

For each part, plug in the values into the formula to find the rate of change.