# Having trouble finding the derivative of an inverse function

• barryj
In summary, the question involves finding the inverse of a function and the correct answer is 1/5. The individual has tried various solutions but is still getting the wrong answer. They are confused about which value to use for the inverse function and are seeking clarification. They mention having a similar example and understanding it, but are still unsure about the current problem.
barryj
Summary: Please see the attached problem and solution

The answer is 1/5. I have tried various solutions and cannot get 1/5.
What is my error?

[Moderator's note: Moved from a technical forum and thus no template.]

Last edited by a moderator:
Carefully parse the question. It doesn't want the solution when x =2.

I am confused. I know I have f' correct as 3X^2 + 2

So, should I use 2 or 13? Neither gives me the supposedly correct answer(per the book) of 1/5

The argument of the inverse function is a =f(x).

OK, so a = 13. if I use 13 instead of 2 I still don't get the right answer.

F(2) = 13 so G(13) = 2.

Sorrry what is 13?

the inverse of F(2)

I have paralleled an example that is almost identical to this problem and I understand it. I think the answer is wrong.

The question wants the (inverse)' when f(x)=2.

There may be a cleverer way but what is x when f(x)=2??

Delta2
1 so f(1) = 2 then g(2) = 1 and I get 1/5
I need to study futher to understand what is being asked.

So plug it in!
(and the term is derivative !)

Thanks

hutchphd

## What is the inverse function?

The inverse function is a function that "undoes" the action of another function. It switches the input and output values of the original function.

## Why is finding the derivative of an inverse function difficult?

Finding the derivative of an inverse function can be difficult because it involves using the chain rule and the inverse function rule, which can be complex and require multiple steps.

## What is the chain rule?

The chain rule is a formula used to find the derivative of a composite function, which is a function that is made up of two or more functions.

## What is the inverse function rule?

The inverse function rule is a formula used to find the derivative of an inverse function. It involves finding the derivative of the original function and then taking the reciprocal of that value.

## What are some tips for finding the derivative of an inverse function?

Some tips for finding the derivative of an inverse function include using the chain rule and inverse function rule, simplifying the function algebraically, and breaking the function into smaller parts to make it easier to differentiate.

Replies
12
Views
3K
Replies
10
Views
2K
Replies
3
Views
1K
Replies
7
Views
1K
Replies
8
Views
1K
Replies
14
Views
1K
Replies
3
Views
940
Replies
3
Views
574
Replies
13
Views
4K
Replies
3
Views
1K