1. ## Inverse function

Hi MHF, knowing that the quadratic function does not admit inverse, and that $\displaystyle \left | X\right | = \sqrt[2]{x^{^2}}$ a modular function have inverse? if yes, how can i find for example y= |x+2|-|3x+2|.

2. ## Re: Inverse function

Originally Posted by Chipset3600
Hi MHF, knowing that the quadratic function does not admit inverse, and that $\displaystyle \left | X\right | = \sqrt[2]{x^{^2}}$ a modular function have inverse? if yes, how can i find for example y= |x+2|-|3x+2|.
Functions can only have inverses if they are one-to-one on their domain. It's pretty obvious that the example you gave is not one-to-one.

3. ## Re: Inverse function

Originally Posted by Prove It
Functions can only have inverses if they are one-to-one on their domain. It's pretty obvious that the example you gave is not one-to-one.
But how can i see if the domain is one to one?
So assuming it to be y = | x |?

4. ## Re: Inverse function

Originally Posted by Chipset3600
But how can i see if the domain is one to one?
So assuming it to be y = | x |?
Have you ever heard of the horizontal line test?

5. ## Re: Inverse function

Originally Posted by Prove It
Have you ever heard of the horizontal line test?
that when I draw a horizontal line can only intercept function in only 1 point.
So the modular function it will never be one to one?

6. ## Re: Inverse function

What is |2|? What is |-2|?

A function is either one-to-one or it is not. I don't know what you mean by "never be". You don't think it is sometimes one-to-one and sometimes not?

7. ## Re: Inverse function

|2|=|-2|=2... The doubt is If there is any modular function that admits inverse?