Proof that $\mathbb Q$ is not cyclic.
69046
Proof of $\mathbb{Q}$ is not cyclic
155219
Prove or Disprove: If every nontrivial subgroup of a group $G$ is cyclic, then $G$ is cyclic.
85586
Proving $\mathbb{Q}$ isn't homeomorphic to $\mathbb{Z}$
62635
Prove that the additive group $ℚ$ is not isomorphic with the multiplicative group $ℚ^*$.
48585
Proving that if $G/Z(G)$ is cyclic, then $G$ is abelian
86015
$\mathbb Q[x]/(x^2+1)$ is not isomorphic to $\mathbb Q[x]/(x^2+2)$
31511
A finite abelian group that does not contain a subgroup isomorphic to $\mathbb Z_p\oplus\mathbb Z_p$, for any prime $p$, is cyclic.
142894
Showing that a group of order $pq$ is cyclic if it has normal subgroups of order $p$ and $q$
17077
Prove or disprove: If $H$ and $G/H$ are cyclic, then $G$ is cyclic.
53432
What is the algebraic closure of $\mathbb F_q$?
46917
How to prove that $GL(n,\mathbb R)$ is not connected subset and open subset of$M_n (\mathbb{R})$
107716
Show that $G$ is cyclic
24561
$\mathbb S_n$ as semidirect product
125668
A proof that BS(1,2) is not polycyclic
119545
Nonzero rationals under multiplication are not a cyclic group
36011
Show that the product of two consecutive natural numbers is never a square.
110944
Proving that $AB-BA=cI$ for nontrivial $c \in \mathbb{C}$