What are functions with the property $f(f(x)) = x$ called?
32575
What's the name for the property of a function $f$ that means $f(f(x))=x$?
24810
Functions satisfying $(b-a)f'(\tfrac{a+b}{2}) = f(b)- f(a)$
29647
Do there exist functions satisfying $f(x+y)=f(x)+f(y)$ that aren't linear?
10774
Why $f(x) = \sqrt{x}$ is a function?
36954
What does the construct f[x_] := f[x] = ... mean?
110704
Find all functions $f$ such that $f(x)+f(\frac{1}{1-x})=x$
47135
Prove if a = b, then f(a) = f(b) for any function f (with natural deduction)
73519
Determine all functions satisfying $f(x + f(x + y)) + f(xy) = x + f(x + y) +yf(x)$
22392
How can a function with a hole (removable discontinuity) equal a function with no hole?
84143
Given any function $g(x): \mathbb{R} \rightarrow \mathbb{R}$, find a function $f(x)$ such that $f(f(x)) = g(x)$.
77331
$f$ function with $\nabla f=\bar{0}$
6482
Why aren't the functions $f(x) = \frac{x-1}{x-1}$ and $f(x) = 1$ the same?
41226
Find $f:f(xf(x)+f(y))=f(x)^2+y$
82597
How to find $ f(x)$ if $f(1-f(x))=x$ for all $x$ $\in \mathbb{R}$
106830
are $f(f(x))=f(x)$ and $f(x)=x$ equivalent?
57938
When do two functions become equal?
26677
thoughts about $f(f(x))=e^x$