Suppose $G=\langle a,b\rangle$ such that $|a|=2$. Prove that if $\langle a\rangle$ is normal in $G$, then $G$ is abelian.
Suppose$G=\langle a,b\rangle$ such that $|a|=2$ . Prove that if $\langle a\rangle$ is normal in $G$ , then $G$ is abelian.