Any element $x \in D_{2n}$, represented as $rx=xr^{-1}$.
1990
Results for elements in Dihedral Groups: $x \notin \langle r\rangle  \Rightarrow rx = xr^{-1}$
86054
$r+r^{-1}$ integral implies $r^n+r^{-n}$ integral
86193
Rigorous proof that $dx dy=r\ dr\ d\theta$
39788
$a+1,a-1$ invertible for nilpotent element
98544
Prove that in any GCD domain every irreducible element is prime
37182
If an element has a unique right inverse, is it invertible?
62732
Prove：$x^d-1 \mid x^n-1$ iff $d \mid n$.
45523
Can the product of two non invertible elements in a ring be invertible?
14161
Proof of when is $A=X^TX$ invertible?
22758
If $\operatorname{ran} F \subseteq \operatorname{dom} G$, then $\operatorname{dom}(G \circ F) = \operatorname{dom} F$.
120245
Use integration by parts to express $I(2n) =$ Integral of $\tan^{2n}x\mathrm{d}x$ in terms of $I(2n − 2)$.
48537
If $\forall x \in R, x^2-x \in Z(G)$, than $R$ is commutative
33645
Proving that an integral domain has at most two elements that satisfy the equation $x^2 = 1$.
77193
Verify that R(p,2) = R(2,p) = p, where R is the Ramsey number
154945
$|px^2+qx+r|\le1$ for all $x$ in $[-1; 1]$, show that $|rx^2+qx+p|\le2$ for all $x$ in $[-1; 1]$
69349
If $A$ is positive definite, then $\int_{\mathbb{R}^n}\mathrm{e}^{-\langle Ax,x\rangle}\text{d}x=\left|\det\left({\pi}^{-1}A\right)\right|^{-1/2}$
97805
$n+1$ is a divisor of $\binom{2n} {n}$