Finding all functions $f : \mathbb{R} \rightarrow \mathbb{R}$ with the given property
66772
$f(f(x)f(y))+f(x+y)=f(xy)$
50552
find functions that $f(m+k)=f(mk-n)$
17700
Find all possible functions, $F(r)$, harmonic in $2$ and $3$ dimensions,
47992
Is there a function $f\colon\mathbb{R}\to\mathbb{R}$ such that every non-empty open interval is mapped onto $\mathbb{R}$?
73519
Determine all functions satisfying $f(x + f(x + y)) + f(xy) = x + f(x + y) +yf(x)$
73074
$f \text{ convex }\Rightarrow \forall (x_0,f(x_0))\in \Gamma(f) \exists a : \forall x\in \mathbb{R}, f(x) \ge a(x-x_0)+f(x_0)$
98363
Expanding two-variable function $f(x,y)$ over the complete sets $\{ g_{i}(x) \}$ and $\{ h_{j}(y) \}$
73850
Cardinality of set of functions
95321
Subspaces of all real-valued continuous functions on $\mathbb{R}^1$
42218
How to find out the following function f which is a function of r?
140978
Real domain and range function to find all functions with nonzero x.
82597
How to find $ f(x)$ if $f(1-f(x))=x$ for all $x$ $\in \mathbb{R}$
11453
Find a real function $f:\mathbb{R}\to\mathbb{R}$ such that $f(f(x)) = -x$?
126878
Monotonic function satisfying darboux property $\Rightarrow$ continuous
43189
Examples of continuous functions $f : \mathbb{R} \to \mathbb{R}$
137883
Cardinality of the set of all (real) discontinuous functions
118154
$f: \mathbb{R} \to \mathbb{R}$ that takes each value in $\mathbb{R}$ twice