Prove $S_g$ retracts to $C$
113919
Surface of genus $g$ does not retract to circle (Hatcher exercise)
120968
Isomorphism of stabilizer over $S_n$ to $S_{n-1}$
15365
Proving that the triangle inequality holds for a metric on $\mathbb{C}$
63836
Show there exists $g:(0,1)\to\mathbb{R}^2$ such that $h\circ g$ constant, $g$ continuously differentiable and $g$ injective
45219
Proving that $C$ is a subset of $f^{-1}[f(C)]$
119793
Proving that $D_{12}\cong S_3 \times C_2$
44934
Show that every normal subgroup can be written as an intersection of $\ker \chi$'s for $\chi \in \operatorname{Irr}(G).$
129845
Prove that $T$ is a subgraph of $G$
52556
Isomorphism of $S^1$.
130081
Show that $A_n$ is the kernel of a group homomorphism of $S_n \rightarrow \{−1,1\}$.
27366
Prove that $g$ is tangent to the graph of $f$
93471
Space of homeomorphisms Homeo$(S^1)$ of $S^1$ deformation retracts onto $O(2)$
92033
Prove that $g$ is a submanifold: $g (t,u,v) = (t^2,u^2,v^2,\sqrt{2}uv, \sqrt{2}tv,\sqrt{2}tu)$
52095
Prove either $G=ST$ or |$G|\geq|S|+|T|$
126930
Finding all group homomorphisms of $S_n\to\mathbb{C}^*$ and $A_n\to\mathbb{C}^*$
7890
Prove the map $\Phi:G\to\operatorname{Aut}G$ with $g\mapsto (x\mapsto g^{-1}xg)$ is an homomorphism.
107163
Proof that $S_3$ isomorphic to $D_3$