Find the dimension of a subspace and the orthogonality complement of another
41347
The dimension of the intersection of two vector subspaces
148595
Find Orthogonal complement
38516
Show a subset is subspace of a vectorspace and find the dimension
22295
Subspace of a separable space is separable
28819
A union of two subspaces not equal to the vector space.
10715
Orthogonal projection and two subspaces
67191
When is the union of a family of subspaces of a vector space also a subspace?
2109
Max dimension of a subspace of singular $n\times n$ matrices
1799
How many k-dimensional subspaces there are in n-dimensional vector space over $\mathbb F_p$?
129549
Showing that the orthogonal projection in a Hilbert space is compact iff the subspace is finite dimensional
78604
How to find basis of intersection of 2 vector spaces with given basis?
97994
Orthogonality Relations Exercise, Brezis' Book Functional Analysis
113326
Proving orthogonality of vectors in a complex vector space
39430
Orthogonal matrix and orthonormal columns
60069
Orthogonal parametrization
74623
Associative rule of subspaces and vector spaces: $(U+V) \cap W = U + (V \cap W)$
69893
An inner product space and its proper closed subspace with trivial orthogonal complement