The Commutator Subgroup is Normal.
49122
Why commutator subgroup is normal to G?
7973
Groups of order $pq$ have a proper normal subgroup
34902
If $H$ is a cyclic subgroup of $G$ and $H$ is normal in $G$, then every subgoup of $H$ is normal in $G$.
11731
Normal subgroups of $S_4$
139096
$|AxA|$ is a constant implies normal subgroup
23941
Normal Subgroups that Intersect Trivially
88199
The commutator subgroup of a quotient in terms of the commutator subgroup and the kernel
43651
Normal subgroups and factor groups
7108
Normal subgroup of prime index
123610
How to show that the commutator subgroup is a normal subgroup
142413
Normal Subgroups of $SU(n)$
128428
Why is the set of commutators not a subgroup?
97928
Normal subgroup of a normal subgroup
116786
normal subgroups of Alternating group
125498
Check whether subgroup is normal in $ S_4$
65037
$H$ is a maximal normal subgroup of $G$ if and only if $G/H$ is simple.
47731
Intersection of all $p$-Sylow subgroups is normal