Question

Find the average rate of change on the indicated intervals: f(x)=x^3-2x; [0,4].

I could really use some help with this problem, if anyone would mind helping ?

Answer 1

do you know the formula for average rate of change?

Answer 2

\[
\frac {f(4) -f(0)}{4-0}
\]

Answer 3

average rate of change for f is the slope of the secant line at x=4 and x=0

Answer 4

Is this one where we can solve it like: [f(x2) - f(x1)]/[x2 - x1]?

Answer 5

I ended up with 56/4 = 14

Answer 6

I can remember nothing about this sort of problem, I'm not ever sure how I would start ?

Answer 7

Could you possibly explain how you got to that answer ?

Answer 8

take your function and feed it x = 4, it will come out to 54. I think of that as one of the two "x"'es, so lets just call it X2. Now take your other value for x, x = 0, (lets call that one X1) and feed it into the same function, It should work out to 0. So just like for finding the slope, we now have a couple of value to use in our numerator: 54-0. For the denominator, we just use the X values without feeding them into the function, so the denom. should look like 4-0. At this point we can just simplify 54/4 to give us 14.

Answer 9

So basically we're just plugging in the values? Very simple, thanks for the help, very much appreciated (: