How to solve the iterated function $f(f(x))=x^2+x$?
13248
How to obtain $f(x)$, if it is known that $f(f(x))=x^2+x$?
28286
About finding the function such that $f(xy)=f(x)f(y)-f(x+y)+1$
44293
Functions satisfying $f\left( f(x)^2+f(y) \right)=xf(x)+y$
151519
If $f(f(x))=x^2-x+1$, what is $f(0)$?
76458
Solve the following functional equation $f(xf(y))+f(yf(x))=2xy$
47443
Iterated polynomial problem
136475
d'Alembert-like functional equation: $f(x+y)+g(x-y)=\lambda f(x)g(y)$
111556
Solving functional equation $f(x+y)+f(x-y)=2f(x)\cos y$?
66406
How to calculate $f(x)$ in $f(f(x)) = e^x$?
74718
Find remainder when $f(x^{12})$ is divided by $f(x)$
110704
Find all functions $f$ such that $f(x)+f(\frac{1}{1-x})=x$
66772
$f(f(x)f(y))+f(x+y)=f(xy)$
21377
Solve integral equation by iteration
132093
Solve $f(f(x))=f(x)$
49794
Solve $f(x^2+y+f(y))=2y+f(x)^2$ over $\mathbb{R}$
26754
Find all continuous functions satisfying $\int_0^xf=(f(x))^2+C$ for some constant $C \neq 0$.
135774
Alternating roots of $f(x) = \exp(x) \sin(x) -1$ and $\exp(x)\cos(x) +1$