New posts in Normal Subgroups

Can a group have two different subgroups of index $2$?

$H$ is normal subgroup of $G$ iff $gHg^{-1}=H$ for every $g$ of $G$

Any Subgroup containing commutator subgroup is normal.

Are there any natural numbers $n$ that satisfy the condition $7921\sigma(n) = 15840n$?

Why in Quotient Group we need normal subgroup?

Are abelian subgroups normal?

Some Subgroup of Dihedral Group is Normal

lattice of subgroup

How do algebraists intuitively picture normal subgroups and ideals?

Prove that $G$ is an abelian group if $\{(g, g):g\in G\}$ is a normal subgroup.