Find A such that $A^2 \neq I$ but $A^4 = I$
129583
Find 3x3 real matrix A such that $A^2 \neq I$ and $A^4 = I$, where I is identity matrix.
94700
Integer solutions for $x^3+2=y^2$?
18125
Counterexamples to the converse to Lagrange's Theorem different from $A_{4}$.
55206
Prove that the equation $x^4+(2k^2)x^2+2k^4$ is not a perfect square
10828
If $A^2 = I$, then $A$ is diagonalizable, and is $I$ if $1$ is its only eigenvalue
16852
$|e^a-e^b| \leq |a-b|$ for complex numbers with non-positive real parts
15191
If $a^2$ divides $b^2$, then $a$ divides $b$
72092
If $A^2 = I$, $B^2=I$ and $(AB)^2=I$, then $AB = BA$
107990
Does there exist an integer $x$ satisfying the following congruences?
60900
If $A^2=-I$, Prove that $\det{A}=1$
87029
Solve $y^2=x^3-4$ in $x,y\in \mathbb{Z}$
52930
Prove or disprove : $a^3\mid b^2 \Rightarrow a\mid b$
20834
Integer solutions to $c=a^2-b^2$
125164
How to prove the existence of $b$ in $Q$ such that $a<b^2<c$ in $Q$?
127901
If $x^2+y^2 \equiv 0\pmod{p}$, then $p \equiv 1 \pmod{4}$
126711
What is the square matrix $A$ equal to if $A=A^2$
114822
Prove or disprove an inequality involving complex numbers