Caley Hamilton why is det (A-A)=0 not a proof?
35155
To prove Cayley-Hamilton theorem, why can't we substitute $A$ for $\lambda$ in $p(\lambda) = \det(\lambda I - A)$?
103061
Why is it true that $\mathrm{adj}(A)A = \det(A) \cdot I$?
35897
Proof of: $AB=0 \Rightarrow Rank(A)+Rank(B) \leq n$
121706
Show $\text{det}(A)$ is divisible by $2^{n-1}$
97990
Why can the row-reduced echelon matrix $R$ only be identity matrix?
60900
If $A^2=-I$, Prove that $\det{A}=1$
125348
Does $\det(A + B) = \det(A) + \det(B)$ hold?
22666
Proving that if $A^n = 0$, then $I - A$ is invertible and $(I - A)^{-1} = I + A + \cdots + A^{n-1}$
86125
If $A$ is idempotent, then the eigenvalues of $A$ are $0$ or $1$
111339
Why the determinant of even-sized magic matrices are zero? Anything special?
155864
Prove or disprove: if $y'=y-y^2$ and $y(0)=a$ where $00$
47829
Prove that $\operatorname{trace}(A^TA) = 0\ \iff\ A = 0$.
150715
Prove that the determinant of skew-symmetric matrices of odd order is zero
57981
Alternative proof of $a\times0= 0$
57771
Let $A\in M_{n\times n}(\Bbb R)$ so that $I\notin span(A,A^2,...,A^n)$. Prove that $\det(A)=0$.
32929
Questions about proving $\lnot \lnot a = a$
31783
Is this proof of $ab = 0$ correct?