Question

I will give you a medal

If f(x)=x^3-x, what is the average rate of change of f(x) over the interval [6, 8]?
a.29.5
b.30
c.43
d.120

Answer 1

so we need to calculate

Answer 2

(f(8)-f(6))/(8-6)=(504-210)/2=147

Answer 3

@16lilyskiv

Answer 4

I'm still a little lost, may you go step by step with me?

Answer 5

ok sure...average rate of change of f(x) over [a,b] is just the slope which is given by

Answer 6

\[\frac{ f(b)-f(a) }{ b-a }\]

Answer 7

so we need to calculate here

Answer 8

\[\frac{ f(8)-f(6) }{ 8-6 }\]

Answer 9

2/2=1

Answer 10

f(8)=8^3-8=504 and f(6)=6^3-6=210
hence the required answer is (504-210)/(8-6)=294/2=147

Answer 11

@16lilyskiv

Answer 12

147 isn't one of the answers... but the closest one is 120. Would it be D?

Answer 13

@jango_IN_DTOWN

Answer 14

or A?

Answer 15

not it cant be.. the solution is unique.

Answer 16

okay thanks for the help

Answer 17

will you once again kindly see the question?

Answer 18

@16lilyskiv

Answer 19

@Michele_Laino