Show that a star convex set $X \subset \mathbb{R^n}$ is simply connected.
33527
Star convex set is simply connected.
116851
Show that f(x) is convex
158399
Show that $\{(x_1,x_2):x_1x_2\geq4,x_1>0,x_2>0\}$ is a convex set
116382
Showing convexity of a function with the restriction over an arbitrary line
113922
Proof that the intersection of any finite number of convex sets is a convex set
115695
If $X$ is a connected subset of a connected space $M$ then the complement of a component of $M \setminus X$ is connected
69497
Show that the set of all $n \times n$ orthogonal matrices, $O(n)$, is a compact subset of $\mbox{GL} (n,\mathbb R)$
157218
If $E\subseteq X$ is connected, $E\cap A\neq\emptyset$ and $E\cap(X\setminus A)\neq\emptyset$ then $E\cap\partial A\neq\emptyset$
53132
A convex subset of a set has 'smaller' boundary than the set?
55486
Topological proof to show a complement set of a set is polygonally connected
9451
Show bounded and convex function on $\mathbb R$ is constant
106718
Prove if C is midpoint convex and closed then its a convex set
57514
The Minkowski sum of two convex sets is convex
158850
Is it true that a boundary of a simply connected and bounded set is connected in $\mathbb{C}$?
31266
Proof of "the continuous image of a connected set is connected"
60887
$d_A(x) = \inf_{a \in A} \|x-a\|$ is convex if and only if $A$ is convex
26919
Intersection of Connected Sets