Proving a matrix is always symmetric
131611
$A^TA$ is always a symmetric matrix?
29788
Eigenvalues of a matrix whose square equals its transpose
3408
Do positive semidefinite matrices have to be symmetric?
15417
Tricky problem on skew-symmetric matrices
145397
How to prove that for every $i$, $a_i = i$
50404
How to prove a matrix is nilpotent?
42141
Proving Distributivity of Matrix Multiplication
86940
Proving an inequality in Eigenvalues of a matrix
30665
Elegant proofs that similar matrices have the same characteristic polynomial?
13723
Doubly stochastic matrix proof
124095
$A$ is a real orthogonal matrix, prove that $ (I+A)^{-1}(I-A)$ is skew-symmetric
87441
Proof involving matrix equation
123679
General Information about Eigenvalues for an 3x3 symmetric matrix
52564
$m\times n$ matrix with an even number of 1s in each row and column
20920
Determinant of a block skew-symmetric matrix
120186
Consistent linear system
87262
How to prove positive semidefiniteness of two matrices through Schur Complement?