1. ## Graphing Functions

I have a question I'm stuck on:

Find two functions such that f(x)= f-1(x). (For all x in domain of f)

It's not f minus 1. I don't know how to type the Value of Inverse of f at x.

An assistance would be greatly appreciated!

2. Huu hello !

What about y=x and y=-x ?

3. Originally Posted by Maga22
I have a question I'm stuck on:

Find two functions such that f(x)= f-1(x). (For all x in domain of f)

It's not f minus 1. I don't know how to type the Value of Inverse of f at x.

An assistance would be greatly appreciated!
Question 1 a. of this thread is relevant: http://www.mathhelpforum.com/math-he...questions.html

See if you can place conditions on a, b, c and d so that the function $y = \frac{ax+b}{cx+d}$ is its own inverse.

4. Originally Posted by Moo
Huu hello !

What about y=x and y=-x ?
Thanks. So it seemed easy. These are two functions such that f(x) = the value of inverse of f at x?

5. Originally Posted by Maga22
Thanks. So it seemed easy. These are two functions such that f(x) = the value of inverse of f at x?
Well, for the second one, f(x) = -x, find the inverse function.

Let y = f(x) = -x.

Now, switch the roles of y and x:
$x = -y$

Now solve for y:
$y = -x$.

This is your inverse function. So
$f^{-1}(x) = -x = f(x)$

You do the one for y = x.

-Dan