Multiple Choice Problem

[SherryYang]

Ok, I know what I did wrong .

Retrieved from Google cache:

f(x) = x^3-x-6

g(x) = inverse of f(x)

Find f'(g(0))g'(0)

Answer choices are:

-6
-1
0
1
Cube root of 6

I got -11, which is none of the answers.

Please do not edit out your posts after you've asked a question. This is an anti-homework measure ~~Felstaff

[jestingrabbit]

What's f(g(x))? What do you get if you apply the chain rule when differentiating that expression?

[Toadise]

What's f(g(x))? What do you get if you apply the chain rule when differentiating that expression?

f'(g(x))g'(x)

[z4lis]

As a general rule, don't delete your post after your question was answered. Others using the search function might find it useful, in the future. It's something like this comic.

[mfb]

Is it just me, or is the function g ill-defined, as long as I assume f: R -> R?
It could be defined as something like f: [-1/sqrt(3),1/sqrt(3)] -> [f(1/sqrt[3]),f(-1/sqrt(3)], but that looks a bit arbitrary.

[jestingrabbit]

Is it just me, or is the function g ill-defined, as long as I assume f: R -> R?
It could be defined as something like f: [-1/sqrt(3),1/sqrt(3)] -> [f(1/sqrt[3]),f(-1/sqrt(3)], but that looks a bit arbitrary.

It is globally illdefined, but its well defined around 0, which is where it counts for the question. Its not that arbitrary, just a little.

What's f(g(x))? What do you get if you apply the chain rule when differentiating that expression?

f'(g(x))g'(x)

Yes, yes it is.

[Yakk]

Editing your posts to erase the question after someone asks it isn't polite. It makes the thread useless for anyone else.

[tomtom2357]

If g(x) is the inverse of f(x) then f(g(x))=x by definition

[mfb]

Please don't dig out all the old threads.
You forgot that there is a derivative involved in the question.

[Darrell88]

Wow whose bumping all those old threads !!!