Operations and Identities
76547
Why are addition and multiplication commutative, but not exponentiation?
138279
Multiplicative order and powers
127664
Inverse elements in the absence of identities/associativity.
46825
The identity det(A) = exp(Tr(ln(A)) for A general
44484
Combinatorial identity $i{n \choose i } =n {n-1 \choose i - 1}$
149686
Combinatorics and trigonometry identity
74611
$\operatorname{Adj} (\mathbf I_n x-\mathbf A)$ when $\operatorname{rank}(\mathbf A)\le n-2$
123483
Prove that $\operatorname{rank}(A) + \operatorname{rank}(B) \ge \operatorname{rank}(A + B)$
106643
problem using identity theorem
89177
$\operatorname{adj}(AB) = \operatorname{adj} B \operatorname{adj} A$
45725
Derivation of an identity with beta function.
102935
Trace and determinant of composition of a left-multiplication and a right-multiplication on a space of matrices
5758
Prove that $I+\lambda A$,$I+\lambda B$,$I+\lambda C$ are invertible and A=B=C
46732
Constructing a function with Flat and OneIdentity attribute with the property that otimes[a]:>a
135799
Trying to understand nested loops, identity matrix
117688
Prove that $\def\Aut{\operatorname{Aut}}\Aut(\mathbf{Z_{n}})\simeq \mathbf{Z_{n}^{*}}$
108688
An identity involving products of sums