Prove that unity of two subspaces is a subspace if and only if one is a subspace of the other
11301
Union of two vector subspaces not a subspace?
105367
Proving $||\vec{a}+\vec{b}|| = ||\vec{a}-\vec{b}|| \iff \vec{a} \perp \vec{b}$
139979
Proof there is a rational between any two reals
33642
Finite dimensional subspace of $C([0,1])$
91022
How do I prove that a subspace of a vector space $X$ is the null space of some linear functional on $X$?
4717
The union of linear subspaces is not necessarily a subspace
4319
Vector space can be written as direct sum of subspaces
56399
Proof for $A \cup B = B$ if and only if $A \subset B$
70413
A vector space over $R$ is not a countable union of proper subspaces
102371
Proving that two vector spaces of equal dimension are isomorphic
18572
Union of a family of connected pairwise not disjoint subspaces is connected
120641
Intersection of three vector subspaces
43504
Proving the existence of a complement subspace $U' \subset V$.
128990
Prove that, at least one of the matrices $A+B$ and $A-B$ has to be singular
73690
If $\mathbb R^3\setminus V$ connected where $V$ is the subspace generated by $\{(1,1,1),(0,1,1)\} $
6547
Given $3$-dimensional subspaces $V, W \subset \Bbb R^5$, there is a nonzero vector in $V \cap W$
63442
Show that if $U$ is an open connected subspace of $\mathbb{R}^2$, then $U$ is path connected