Show that there exits infinitely many functions $f:\mathbb{N}\to\mathbb{N}$
130636
A result of Erdős on increasing multiplicative functions
124562
$f:\mathbb{R}^n \to \mathbb{R}$ has expansion $\sum_i g_i(x)x^i$
132384
Defining indefinitely many functions
138026
To show that $n!f(x) \in \mathbb{Z}[x]$
76148
Show that $\exists c \in \mathbb{R} : f(c) = 0$
62709
Functions that are sets of all function - proofs
48891
Show that: lim$_{n\rightarrow \infty}\,f(x_n)=f(\text{lim}_{n \rightarrow \infty} \, x_n)$
103625
Number of increasing functions from $\{1,2,\dots, n\}$ to itself.
57282
A Riemann integrable function must have infinitely many points of continuity
58597
A characterization of functions from $\mathbb R^n$ to $\mathbb R^m$ which are continuous
128350
Number of non-decreasing functions between two finite sets
64583
Number of surjective functions from A to B
40566
Counting surjective functions
33157
Proof that an infinite subset of $\mathbb{N}$ is countable
117793
Finding a function $\mathbb{N} \to \mathbb{N}$ that is surjective but not injective.
28399
Showing $f$ is constant
53168
Surjective, Injective, Bijective Functions from $\mathbb Z$ to itself