Question

The set Z left (Gright) =left g in G:xg=gxfor all x in Gright is called ______
a.element
b.order
c.coset
d.centre

Answer 1

$Z(G)=\{g\in G: \ xg=gx, \ \forall x\in G\}$ is called the center of $G$ .

Answer: d.