Proof that the image of a closed cone under a linear transformation is a closed cone
47975
Closed cone in the euclidean space $\mathbb{R}^n$
50037
Proving that kernels of evaluation maps are generated by the $x_i - a_i$
32420
A complete orthonormal system contained in a dense sub-space.
117508
Prove that the closed unit ball of $L^2[a,b]$ is closed in $L^1[a,b]$
59424
Showing that $B=\{(x,y) \in \Bbb{R^2} \mid \ xy>0 \}$ is an open set
2575
Showing that $\mathbb{R}$ is connected
57406
Proving the volume of a cone
150861
Intuition about degenerate conics
10042
How to Show that Linear transformation is invertible?
62303
For $V$ vector space of dimension $n$ under $\mathbb C$ and $T: V \to V $ linear transformation , show $V= \ker T^n \oplus $ Im $T^n$
98759
Proof of "Dual normed vector space is complete"
90599
Trouble with proving $A$ is an integrally closed domain $\Rightarrow$ $A[t]$ is integrally closed domain
94378
Is Linear transformations $T_1,T_2 : \mathbb{R}^n\rightarrow \mathbb{R}^n$ Invertible?
127591
How to prove that the collection of rank-k matrices forms a closed subset of the space of matrices?
63104
Dual cone of $K = \{(x,t) \mid \| \boldsymbol{x} \|_1 \le t \}$
82355
When is the image of a linear operator (between Banach spaces) closed?
152364
How to compute the image of a polyhedron under a linear transformation