Find all functions satisfying $f\left(f(x)f(y)\right)+f(x+y)=f(xy)$
66772
$f(f(x)f(y))+f(x+y)=f(xy)$
142682
Find $f(x)$ where $ f(x)+f\left(\frac{1-x}x\right)=x$
19019
Find all functions $f:\Bbb{Q}\rightarrow \Bbb{Q}$ such that $f(x)+f(t)=f(y)+f(z)$ for all rational numbers $x<y<z<t$ that form an AP
86128
Find all functions $ f : \Bbb R \to \Bbb R$ which satisfy $f(x)f(y) = f(x + y) + xy$ for all $x, y ∈ \Bbb R$.
55693
The functional equation $ f \big( x - f ( y ) \big) = f \big( f ( y ) \big) + x f ( y ) + f ( x ) - 1 $
104278
Finding function $f(x)$ which satisfy given functional equation
28286
About finding the function such that $f(xy)=f(x)f(y)-f(x+y)+1$
81921
If $f(x + y) = f(x) + f(y)$ showing that $f(cx) = cf(x)$ holds for rational $c$
49211
Solving $f(x+y) = f(x)f(y)f(xy)$
20568
Does the following have a solution for f(x,y)?
28088
When is $f_{xy}(x,y)\neq f_{yx}(x,y)?$
105319
A calculus problem with functions such that $f''(x) = g(x)$ and $g''(x) = f(x)$
50833
Find all $f:\mathbb R\to\mathbb R$ such that $\forall x,y\in\mathbb R$ the given equality holds: $xf(y)+yf(x)=(x+y)f(x)f(y)$.
14975
Functions satisfying $f:\mathbb{N}\rightarrow\ \mathbb{N}$ and $f(f(n))+f(n+1)=n+2$
39090
Finding functions such that $f(g(x)) = f(x)g(x)$
132488
Find all entire functions $f(z)$ such that $|f(z)|=1$ for $|z|=1$
31732
If the function $f$ satisfies the equation $f(xf(y)+x)=xy+f(x)$, find $f$