A problem on norm preserving and angle preserving and their relations.
28719
Question about Angle-Preserving Operators
3420
Uniqueness of Extended Euclidean Algorithm
157213
Application of Luca's theorem
57619
Norms Induced by Inner Products and the Parallelogram Law
123505
how to prove vector norm equivalence in finite dimensional space($\mathbb{R}^{n}$)?
105781
Least squares problem with constraint on the unit sphere
16692
a representation condition of Hilbert space
75215
Properties of invertible matrices
5506
Perturbation property of Orthonormal basis for Hilbert space
143869
Showing that the norm of the canonical projection $X\to X/M$ is $1$
15417
Tricky problem on skew-symmetric matrices
31302
Hilbert Schmidt Norm-Rank-inequality
130436
bisectors of an angle in a triangle intersect at a single point - proof verification
32420
A complete orthonormal system contained in a dense sub-space.
122305
Proof of matrix norm property: submultiplicativity
112362
fixed point problem for orthogonal transformation
81879
$Av=λv$ basis proof problems