Map of degree two from $S^2$ to the torus $T^2$.
100736
Why every map $f : S^n \to T^n (n>1)$ has topological degree zero?
64993
Connectedness of the $S^2$ sphere
135059
Prove that the unit circle, $S^1:=\{(x,y)\in \mathbb{R}^2: x^2+y^2=1\}$, Is a one-dimensional manifold
67234
The function $G: x \mapsto 2^{x^2}$ maps $\mathbb{R}$ onto $\{ x \in \mathbb{R} : x \geq 1 \}$
103081
Square-tiling a torus
53327
$C_2 \times C_2$ and $C_4$
127436
Conformal Maps onto the Unit Disc in $\mathbb{C}$
18141
Embedding $S_n$ into $A_{n+2}$
154837
mapping properties of $(1−z)^i$
100107
How can I prove that a linear map $T:V\to V$ such that $T^2 = I$ is equal to the Identity map?
57816
$(S^1 \times [0,1])/\sim$ homeomorphic to unit disk $ D^2$
52517
Construction of $\mathbb{CP}^2$ from $S^2\times S^2$
45432
Showing that $f:(0,2\pi]\to S^1$ is not a homeomorphism
117151
Conformal automorphism of unit disk that interchanges two given points
157597
Homeomorphism between $\mathbb{Q}$ and $\mathbb{Q}(>0)$, and $\mathbb{Q}(\ge 0)$
41872
Show that $\mathbb{R}^2$ is not homeomorphic to $\mathbb{R}^2 \setminus\{(0,0)\}$
16789
Prove that $T^2$ is the zero transformation if and only if $\mathrm{range}(T) \subseteq \ker(T)$.