If $A^2=I$ and $\lambda \not =-1$, then $A=I$
100107
How can I prove that a linear map $T:V\to V$ such that $T^2 = I$ is equal to the Identity map?
6169
If $ A^3=A$ prove that $Ker\left(A-I\right)+Im\left(A-I\right)=V$
118304
If $A^2 = I$ (Identity Matrix) then $A = \pm I$
43913
Prove that if $A^*+A=AA^*$ then $A$ is normal
32929
Questions about proving $\lnot \lnot a = a$
32965
Proving that for infinite $\kappa$, $|[\kappa]^\lambda|=\kappa^\lambda$
64747
If $A^m=I$ then A is Diagonalizable
118283
Show that if $A^{n}=I$ then $A$ is diagonalizable.
60348
How do I prove $F(a)=F(a^2)?$
88982
Prove that for any two sets $A$ and $B$, $A\notin B$ or $B\notin A$
12927
$A^2+B^2=AB$ and $BA-AB$ is non-singular
141628
How did the equation $|A- \lambda I| = 0$ came for finding Eigen values of a Matrix
147627
Relation between condition numbers $\kappa(A^T A)$ and $\kappa(A)$
5526
Prove that $ℤ[i]^*= \{1,-1,i,-i\}$
4952
Let $A$ be a diagonalizable matrix and $\lambda$ be an eigenvalue of A. Prove that rank($\lambda I - A$) = rank(($\lambda I - A)^2$).
42334
Does $\lambda$ $\mathbf u$ $= 0$ imply $\lambda = 0$ or $\mathbf u$ $= 0$?
135694
Proving $\kappa^{\lambda} = |\{X: X \subseteq \kappa, |X|=\lambda\}|$