Proving $AB = BA$ when $A$ is the Identity matrix times a scalar.
59041
Centre of $GL_n(\mathbb R)$
141173
Are there matrices such that $AB=I$ and $BA \neq I$
26570
Prove $\operatorname{rank}(AB) = \operatorname{rank}(B)$
138342
Proof of a matrix exponential identity
14646
Prove $\det(kA)=k^n\det A$
140252
Matrices - Conditions for $AB+BA=0$
20110
How to prove $(AB)^T=B^T A^T$
145876
$AB-BA=A$ implies $A$ is singular and $A$ is nilpotent.
7712
How to prove the both identity (matrix)
85167
When A and B are of different order given the $\det(AB)$,then calculate $\det(BA)$
123044
Commutative matrices are multiples of the identity
50266
In the following figure prove that: $AK||BC$
146795
Proof If $AB-I$ Invertible then $BA-I$ invertible.
80544
Need verification - Prove a Hermitian matrix $(\textbf{A}^\ast = \textbf{A})$ has only real eigenvalues
98135
Show that the determinant of $A$ is equal to the product of its eigenvalues
130281
Proving $a^ab^b + a^bb^a \le 1$, given $a + b = 1$
101040
Prove the equality: $\det\left[\begin{smallmatrix} -2a &a+b &a+c \\ b+a&-2b &b+c \\ c+a&c+b &-2c \end{smallmatrix}\right] = 4(a+b)(b+c)(c+a)$