Find all functions $f:\Bbb N\rightarrow \Bbb R $ such that: $f(m+k)=f(mk-n)$
50552
find functions that $f(m+k)=f(mk-n)$
24810
Functions satisfying $(b-a)f'(\tfrac{a+b}{2}) = f(b)- f(a)$
75448
Find all function satisfying $f(f(n))+f(n)=2n+3k$
37976
Find all functions $f$ such that $(x+y)f(x)+f(y^2)=(x+y)f(y)+f(x^2)$
10253
Proving that all entire & injective functions take the form $f = ax + b$?
114118
Define the image of the function $f :\Bbb Z \times \Bbb N →\Bbb R$ given by $f(a, b) = \frac{a−4}{7b}$?
112948
Fibonacci addition law $F_{n+m} = F_{n-1}F_m + F_n F_{m+1}$
102299
Bijection between $\mathbb{R}^n$ and $\mathbb{R}^m$
50833
Find all $f:\mathbb R\to\mathbb R$ such that $\forall x,y\in\mathbb R$ the given equality holds: $xf(y)+yf(x)=(x+y)f(x)f(y)$.
156778
Finding functions satisfying $f(f(x))+f(x)+x=0$
129052
Find all functions satisfying $\frac{1}{f(a)}+ \frac{1}{f(b)} = \frac{1}{f(c)} $ whenever $\frac{1}{a}+ \frac{1}{b} = \frac{1}{c} $
81799
Examples of functions where $f(ab)=f(a)+f(b)$
11828
continuous functions on $\mathbb R$ such that $g(x+y)=g(x)g(y)$
62111
Functional Equation $f(mn)=f(m)f(n)$.
91947
Proof of $ f:I_n \rightarrow I_m \Rightarrow n = m$
28692
Find if set $I$ of all injective functions $\mathbb{N} \rightarrow \mathbb{N}$ is equinumerous to $\mathbb{R}$
71156
$f(x) = \frac {ax+b}{cx+d}$ , bijection $f: \Bbb R \to\Bbb R$?