Respuesta :

Answer:

Step-by-step explanation:

We are given that G be  a finite group with [tex]x,y\in G[/tex] have two elements of order two.

We have to prove that <x,y> is either abelian or isomorphic  to a dihedral group.

<x,y> means the group generated by two elements of order 2.

We know that  [tex]z_n[/tex] is a cyclic group and  number of elements of order 2 is always odd in number and generated by one element  .So , given group is not isomorphic to [tex]Z_n[/tex]

But we are given that two elements of order 2 in given group

Therefore, group G can be [tex]K_4[/tex]or dihedral group

Because the groups generated by two elements of order 2 are [tex]K_4[/tex] and dihedral group.

We know that [tex]K_4[/tex] is abelian group of order 4 and every element of  [tex]K_4[/tex] is of order 2 except identity element and generated by 2 elements of order 2 and dihedral group can be  also generated by two elements of order 2

Hence, <x,y> is isomorphic to [tex]K_4[/tex] or [tex]D_2[/tex].