# If g is the inverse of f and if #f(x)=x^3-5x^2+2x-1#, how do you calculate g'(-9) if the domain of f(x) is the set of integers less than 0? Thanks in advance for taking time to help me out. Steve?

##### 1 Answer

Sep 13, 2016

Use

#### Explanation:

We have, in this case

That is: we need

We must solve

Solve

If you know the rational zeros theorem, use it. Otherwise, you'll need to solve "by inspection". (That's the fancy name for "guess and check".)

Try

and