Find an orthonormal basis in which $E$ is represented by matrix
6319
Finding an orthonormal basis for a matrix
61718
Can a basis for a vector space be made up of matrices instead of vectors?
113779
If $P$ is an orthogonal matrix its columns form an orthonormal set.
137209
Finding the Matrix of a Linear Operator Satisfying a Polynomial
16692
a representation condition of Hilbert space
16419
Is there any fast method of matrix exponentiation?
149219
If $A$ is a non-square matrix with orthonormal columns, what is $A^+$?
88386
Derivative of matrix exponential at $0$
93550
How to find the matrix representation of an operator from its action on a basis?
145885
Linear transformation preserving orthogonality
38412
Basis for tensor products
137180
Orthonormal basis with specific norm
152742
Finding a basis of an infinite-dimensional vector space?
121769
How to find the matrix representation of a linear tranformation
5506
Perturbation property of Orthonormal basis for Hilbert space
133711
Orthogonal basis for infinite-dimensional vector spaces
91257
Fourier basis functions