Is $f : A \to P(A), a \mapsto \{a\}$ injective or surjective?
69852
Confused on Injection and Surjection Question - Not sure how to justify
64583
Number of surjective functions from A to B
63146
Proof of properties of injective and surjective functions.
21707
Constructing a Bijective function via an injective and surjective one.
37308
Let $f:K\to K$ with $\|f(x)-f(y)\|\geq ||x-y||$ for all $x,y$. Show that equality holds and that $f$ is surjective.
29154
$f$ is continuous and open implies $f$ injective
21391
Proving Functions are Surjective
72251
$g\circ f$ is Surjective and $g$ is Injective then Prove that $f$ is surjective
16610
Surjectivity of a map from a space to itself
124333
A bijection between $\mathbb{N}$ and $\mathbb{P}(\mathbb{N})$?
34260
Injective function from $\mathbb{R}^2$ to $\mathbb{R}$?
130363
Prove composition of two surjections is surjection
45380
Surjectivity implies injectivity and conversely
152438
Is the composition of two injective functions injective?
155063
Is Cl(f(A)) a subset of f(Cl(A))?
93040
$f$ is surjective iff it has a right inverse: using the axiom of choice and errors in ProofWiki
148500
Understanding this theorem and how to go about proving it surjectivity?