# Suppose f(1) = 2, f '(1) = 3 and f '(2) =4, then f^-1(2)=?

1. Dec 22, 2011

### aizeltine

1. The problem statement, all variables and given/known data

Suppose f(1) = 2, f '(1) = 3 and f '(2) =4, then f^-1(2)=?

2. Relevant equations

I dont even know what eqn to use
3. The attempt at a solution
Knowing that I dont know what eqn to use, how do i solve this
just plseas give me direct steps on how to answer it..

2. Dec 22, 2011

### D H

Staff Emeritus
You don't need the derivatives to solve this problem. Presumably those are for another part of the problem.

Hint: What is $f^{-1}(f(x))$?

3. Dec 22, 2011

### HallsofIvy

You need to learn the definition of $f^{-1}(x)$.

4. Dec 22, 2011

### epenguin

Is this all the problem?

There appears to be redundant, or rather irrelevant, information there.

5. Dec 22, 2011