Confusion about sum of vector subspaces
139988
Counter example for a result of intersection of subspaces
48579
How to find the orthogonal complement of a subspace?
33559
Product or sum of invertible matrix give an invertible matrix?
15576
Addition of two subspaces
23740
Confused about the definition of subspace
137873
Problems that involves two facts in the definition of vector spaces
13421
Let $X,Y,Z$ be subspaces of $V$ so that $X$ is a subspace of $Y$. Prove that $Y\cap (X+Z)=X+(Y\cap Z)$
64353
Does the set of matrix commutators form a subspace?
70413
A vector space over $R$ is not a countable union of proper subspaces
28819
A union of two subspaces not equal to the vector space.
120641
Intersection of three vector subspaces
18921
Linear Transformations: Proving 1 dimensional subspace goes to 1 dimensional
150135
The intersection of an infinite number of subspaces is a subspace
107056
Notation for Subspaces
15560
Prove that the union of three subspaces of $V$ is a subspace iff one of the subspaces contains the other two.
156985
Question Concerning Vectors
38516
Show a subset is subspace of a vectorspace and find the dimension