Prove V is a convex set
6335
Proving that the set enclosed by an ellipse is convex
71829
Is closure of convex subset of $X$ is again a convex subset of $X$?
156101
Is the convex hull of closed set in $\mathbb R^{n}$ is closed?
40403
Show that the function is convex
9451
Show bounded and convex function on $\mathbb R$ is constant
142740
If $\varphi \in E'$ and $A$ is convex and open then $\varphi (A)$ is an open interval
57406
Proving the volume of a cone
113922
Proof that the intersection of any finite number of convex sets is a convex set
107321
How to show convexity of a ball in metric space?
89089
Prove that there is a unique inner product on $V$
116548
How to prove the real value function $f$ is convex on $[a,d]$ if $f$ is convex on both $[a,c]$ and $[b,d]$? ($a<b<c<d$).
78229
Proving that the tangent to a convex function is always below the function
15491
Prove that $f:\mathbb R^n\to\mathbb R$ is affine if and only if it is convex and concave
18763
injective holomorphic function on a convex set
124786
Prove that V contains a subspace of each dimension
77217
Proof that a coordinate-wise convex function is convex?
41520
Prove that $L(V,W)$ forms a vector space