A function $f\colon E\to F$ between finite sets is injective iff it is surjective iff it is bijective
88201
Suppose $X$ is a finite set and $f : X \to X$ is a function. Then $f$ is injective if and only if $f$ is surjective.
117502
Proving that a certain continuous function is surjective.
118192
Is there a bijective function $f: \mathbb{R}\to\mathbb{R}$ that is discontinuous?
11813
Injective functions also surjective?
21663
Bijection between power sets of sets implies bijection between sets?
133699
Proving that there is a bijection between $A$ and $B$.
24107
Bijection $f:\mathcal{P}(A)\to(A\to \{0,1\})$
49592
Show that, if $f:A\to B$ is a function, with $A$ and $B$ being finite sets, and $|A|=|B|$, then $f$ is one to one iff $f$ is onto.
10307
Show the inverse of a bijective function is bijective
38286
Proving the Cantor Pairing Function Bijective
124374
A bijective function between a square and its side
132868
Bijection between an infinite set and its union of a countably infinite set
23464
How to find a explicit bijection for some $f:A\times B \rightarrow B \times A$
16092
How to prove that the composition of two surjective functions is surjective
48765
Let $S$ and $T$ be finite non-empty sets such that $|S| = |T|$. Show that the function $f : S\to T$ is onto if and only if it is one-to-one.
20199
Find a surjective function $f:\mathbb{N}\to \mathbb{Q}$
88278
Show $S = f^{-1}(f(S))$ for all subsets $S$ iff $f$ is injective