1. ## Simple equation solution

OK, this should be pretty simple.

I have a function, such that

$\displaystyle y=f(x)$

How can I obtain a solution for when $\displaystyle y=x$, i.e,

$\displaystyle x=f(x)$

At the moment I'm doing it iteratively, but I'm sure there is a simple analytical solution.

2. $\displaystyle f(x)=\sqrt{x^2}$

3. Originally Posted by Guffmeister
OK, this should be pretty simple.

I have a function, such that

$\displaystyle y=f(x)$

How can I obtain a solution for when $\displaystyle y=x$, i.e,

$\displaystyle x=f(x)$

At the moment I'm doing it iteratively, but I'm sure there is a simple analytical solution.
Obviously for certain functions an analytical solution is possible.

Otherwise an approximate solution using an appropriate iterative procedure is all that can be suggested.

But since you do not say what the rule for f(x) is, nothing more can be said.

4. Sorry...I have just realised how ridiculous that question is. Please delete this thread if you want.