Commutator subgroup of cyclic group












2












$begingroup$


Find commutator subgroup of cyclic group.



I know that every cyclic group is abelian group and commutator subgroup of any abelian group is trivial group.
I just need help to prove this.










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$endgroup$








  • 2




    $begingroup$
    Please include the definitions you've learned: What is the commutator subgroup of a group? What do you mean by the "the commutator subgroup of any abelian group is the trivial group"? Remember, a cyclic group happens to be an abelian group.
    $endgroup$
    – Namaste
    Jan 25 at 18:11
















2












$begingroup$


Find commutator subgroup of cyclic group.



I know that every cyclic group is abelian group and commutator subgroup of any abelian group is trivial group.
I just need help to prove this.










share|cite|improve this question









$endgroup$








  • 2




    $begingroup$
    Please include the definitions you've learned: What is the commutator subgroup of a group? What do you mean by the "the commutator subgroup of any abelian group is the trivial group"? Remember, a cyclic group happens to be an abelian group.
    $endgroup$
    – Namaste
    Jan 25 at 18:11














2












2








2





$begingroup$


Find commutator subgroup of cyclic group.



I know that every cyclic group is abelian group and commutator subgroup of any abelian group is trivial group.
I just need help to prove this.










share|cite|improve this question









$endgroup$




Find commutator subgroup of cyclic group.



I know that every cyclic group is abelian group and commutator subgroup of any abelian group is trivial group.
I just need help to prove this.







abstract-algebra abelian-groups cyclic-groups






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asked Jan 25 at 18:06









user638212user638212

302




302








  • 2




    $begingroup$
    Please include the definitions you've learned: What is the commutator subgroup of a group? What do you mean by the "the commutator subgroup of any abelian group is the trivial group"? Remember, a cyclic group happens to be an abelian group.
    $endgroup$
    – Namaste
    Jan 25 at 18:11














  • 2




    $begingroup$
    Please include the definitions you've learned: What is the commutator subgroup of a group? What do you mean by the "the commutator subgroup of any abelian group is the trivial group"? Remember, a cyclic group happens to be an abelian group.
    $endgroup$
    – Namaste
    Jan 25 at 18:11








2




2




$begingroup$
Please include the definitions you've learned: What is the commutator subgroup of a group? What do you mean by the "the commutator subgroup of any abelian group is the trivial group"? Remember, a cyclic group happens to be an abelian group.
$endgroup$
– Namaste
Jan 25 at 18:11




$begingroup$
Please include the definitions you've learned: What is the commutator subgroup of a group? What do you mean by the "the commutator subgroup of any abelian group is the trivial group"? Remember, a cyclic group happens to be an abelian group.
$endgroup$
– Namaste
Jan 25 at 18:11










3 Answers
3






active

oldest

votes


















1












$begingroup$

Every cyclic group is abelian:



Indeed, if $G$ is cyclic, then there exists $a$ such that $G=left<aright>$.



Let $g,hin G$; then there exists $n,minmathbb Z$ such that $g=a^n$ and $h=a^m$. Therefore $$gh=(a^n)(a^m) = a^{n+m}=(a^m)(a^n) = hg$$



The commutator subgroup of every abelian group is trivial:



Indeed, the commutator subgroup is generated by elements of the form $[g,h]:=ghg^{-1}h^{-1}$ for $g,hin G$. If $g,h$ commutes, then $ghg^{-1}h^{-1}=gg^{-1}hh^{-1}= ecdot e = e$. Therefore, the commutator subgroup is trivial.






share|cite|improve this answer











$endgroup$





















    3












    $begingroup$

    The commutator is defined as $[a,b]=aba^{-1}b^{-1}$. Since the group is cyclic, it's Abelian. So, we have that $forall a,b: ab=ba$. This gives that $aba^{-1}b^{-1}=e$ always. So, the commutator subgroup is $e$.






    share|cite|improve this answer









    $endgroup$





















      1












      $begingroup$

      Forgive me if perhaps I misunderstood, but is there anything more to this question than:
      [$g,b$]=$g^{-1}b^{-1}gb$= $c^{-i}c^{-j}c^ic^j$=$e$ and thus the the commutator subgroup is the minimum subgroup on the set {$e$}, which is the trivial group.
      Of course, it would depend on how exactly the commutator was defined to you( maybe your professor defined it through quotients, which would yield another simple solution)






      share|cite|improve this answer











      $endgroup$













      • $begingroup$
        I don't understand your formula for $[gb]$.
        $endgroup$
        – Yanko
        Jan 25 at 19:36










      • $begingroup$
        Oh sorry i forgot the comma.
        $endgroup$
        – Marat Aliev
        Jan 25 at 20:26










      • $begingroup$
        That's not that. I don't understand where the $c$'s come from.
        $endgroup$
        – Yanko
        Jan 26 at 13:28






      • 1




        $begingroup$
        Oh, sorry forgot that as well. the $c$ is to denote the generator of the cyclic group. Needs another edit, sorry for the mistype
        $endgroup$
        – Marat Aliev
        Jan 26 at 18:35











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      3 Answers
      3






      active

      oldest

      votes








      3 Answers
      3






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes









      1












      $begingroup$

      Every cyclic group is abelian:



      Indeed, if $G$ is cyclic, then there exists $a$ such that $G=left<aright>$.



      Let $g,hin G$; then there exists $n,minmathbb Z$ such that $g=a^n$ and $h=a^m$. Therefore $$gh=(a^n)(a^m) = a^{n+m}=(a^m)(a^n) = hg$$



      The commutator subgroup of every abelian group is trivial:



      Indeed, the commutator subgroup is generated by elements of the form $[g,h]:=ghg^{-1}h^{-1}$ for $g,hin G$. If $g,h$ commutes, then $ghg^{-1}h^{-1}=gg^{-1}hh^{-1}= ecdot e = e$. Therefore, the commutator subgroup is trivial.






      share|cite|improve this answer











      $endgroup$


















        1












        $begingroup$

        Every cyclic group is abelian:



        Indeed, if $G$ is cyclic, then there exists $a$ such that $G=left<aright>$.



        Let $g,hin G$; then there exists $n,minmathbb Z$ such that $g=a^n$ and $h=a^m$. Therefore $$gh=(a^n)(a^m) = a^{n+m}=(a^m)(a^n) = hg$$



        The commutator subgroup of every abelian group is trivial:



        Indeed, the commutator subgroup is generated by elements of the form $[g,h]:=ghg^{-1}h^{-1}$ for $g,hin G$. If $g,h$ commutes, then $ghg^{-1}h^{-1}=gg^{-1}hh^{-1}= ecdot e = e$. Therefore, the commutator subgroup is trivial.






        share|cite|improve this answer











        $endgroup$
















          1












          1








          1





          $begingroup$

          Every cyclic group is abelian:



          Indeed, if $G$ is cyclic, then there exists $a$ such that $G=left<aright>$.



          Let $g,hin G$; then there exists $n,minmathbb Z$ such that $g=a^n$ and $h=a^m$. Therefore $$gh=(a^n)(a^m) = a^{n+m}=(a^m)(a^n) = hg$$



          The commutator subgroup of every abelian group is trivial:



          Indeed, the commutator subgroup is generated by elements of the form $[g,h]:=ghg^{-1}h^{-1}$ for $g,hin G$. If $g,h$ commutes, then $ghg^{-1}h^{-1}=gg^{-1}hh^{-1}= ecdot e = e$. Therefore, the commutator subgroup is trivial.






          share|cite|improve this answer











          $endgroup$



          Every cyclic group is abelian:



          Indeed, if $G$ is cyclic, then there exists $a$ such that $G=left<aright>$.



          Let $g,hin G$; then there exists $n,minmathbb Z$ such that $g=a^n$ and $h=a^m$. Therefore $$gh=(a^n)(a^m) = a^{n+m}=(a^m)(a^n) = hg$$



          The commutator subgroup of every abelian group is trivial:



          Indeed, the commutator subgroup is generated by elements of the form $[g,h]:=ghg^{-1}h^{-1}$ for $g,hin G$. If $g,h$ commutes, then $ghg^{-1}h^{-1}=gg^{-1}hh^{-1}= ecdot e = e$. Therefore, the commutator subgroup is trivial.







          share|cite|improve this answer














          share|cite|improve this answer



          share|cite|improve this answer








          edited Jan 25 at 19:16









          J. W. Tanner

          3,4601320




          3,4601320










          answered Jan 25 at 18:15









          YankoYanko

          7,9551830




          7,9551830























              3












              $begingroup$

              The commutator is defined as $[a,b]=aba^{-1}b^{-1}$. Since the group is cyclic, it's Abelian. So, we have that $forall a,b: ab=ba$. This gives that $aba^{-1}b^{-1}=e$ always. So, the commutator subgroup is $e$.






              share|cite|improve this answer









              $endgroup$


















                3












                $begingroup$

                The commutator is defined as $[a,b]=aba^{-1}b^{-1}$. Since the group is cyclic, it's Abelian. So, we have that $forall a,b: ab=ba$. This gives that $aba^{-1}b^{-1}=e$ always. So, the commutator subgroup is $e$.






                share|cite|improve this answer









                $endgroup$
















                  3












                  3








                  3





                  $begingroup$

                  The commutator is defined as $[a,b]=aba^{-1}b^{-1}$. Since the group is cyclic, it's Abelian. So, we have that $forall a,b: ab=ba$. This gives that $aba^{-1}b^{-1}=e$ always. So, the commutator subgroup is $e$.






                  share|cite|improve this answer









                  $endgroup$



                  The commutator is defined as $[a,b]=aba^{-1}b^{-1}$. Since the group is cyclic, it's Abelian. So, we have that $forall a,b: ab=ba$. This gives that $aba^{-1}b^{-1}=e$ always. So, the commutator subgroup is $e$.







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Jan 25 at 18:15









                  stressed outstressed out

                  6,5931939




                  6,5931939























                      1












                      $begingroup$

                      Forgive me if perhaps I misunderstood, but is there anything more to this question than:
                      [$g,b$]=$g^{-1}b^{-1}gb$= $c^{-i}c^{-j}c^ic^j$=$e$ and thus the the commutator subgroup is the minimum subgroup on the set {$e$}, which is the trivial group.
                      Of course, it would depend on how exactly the commutator was defined to you( maybe your professor defined it through quotients, which would yield another simple solution)






                      share|cite|improve this answer











                      $endgroup$













                      • $begingroup$
                        I don't understand your formula for $[gb]$.
                        $endgroup$
                        – Yanko
                        Jan 25 at 19:36










                      • $begingroup$
                        Oh sorry i forgot the comma.
                        $endgroup$
                        – Marat Aliev
                        Jan 25 at 20:26










                      • $begingroup$
                        That's not that. I don't understand where the $c$'s come from.
                        $endgroup$
                        – Yanko
                        Jan 26 at 13:28






                      • 1




                        $begingroup$
                        Oh, sorry forgot that as well. the $c$ is to denote the generator of the cyclic group. Needs another edit, sorry for the mistype
                        $endgroup$
                        – Marat Aliev
                        Jan 26 at 18:35
















                      1












                      $begingroup$

                      Forgive me if perhaps I misunderstood, but is there anything more to this question than:
                      [$g,b$]=$g^{-1}b^{-1}gb$= $c^{-i}c^{-j}c^ic^j$=$e$ and thus the the commutator subgroup is the minimum subgroup on the set {$e$}, which is the trivial group.
                      Of course, it would depend on how exactly the commutator was defined to you( maybe your professor defined it through quotients, which would yield another simple solution)






                      share|cite|improve this answer











                      $endgroup$













                      • $begingroup$
                        I don't understand your formula for $[gb]$.
                        $endgroup$
                        – Yanko
                        Jan 25 at 19:36










                      • $begingroup$
                        Oh sorry i forgot the comma.
                        $endgroup$
                        – Marat Aliev
                        Jan 25 at 20:26










                      • $begingroup$
                        That's not that. I don't understand where the $c$'s come from.
                        $endgroup$
                        – Yanko
                        Jan 26 at 13:28






                      • 1




                        $begingroup$
                        Oh, sorry forgot that as well. the $c$ is to denote the generator of the cyclic group. Needs another edit, sorry for the mistype
                        $endgroup$
                        – Marat Aliev
                        Jan 26 at 18:35














                      1












                      1








                      1





                      $begingroup$

                      Forgive me if perhaps I misunderstood, but is there anything more to this question than:
                      [$g,b$]=$g^{-1}b^{-1}gb$= $c^{-i}c^{-j}c^ic^j$=$e$ and thus the the commutator subgroup is the minimum subgroup on the set {$e$}, which is the trivial group.
                      Of course, it would depend on how exactly the commutator was defined to you( maybe your professor defined it through quotients, which would yield another simple solution)






                      share|cite|improve this answer











                      $endgroup$



                      Forgive me if perhaps I misunderstood, but is there anything more to this question than:
                      [$g,b$]=$g^{-1}b^{-1}gb$= $c^{-i}c^{-j}c^ic^j$=$e$ and thus the the commutator subgroup is the minimum subgroup on the set {$e$}, which is the trivial group.
                      Of course, it would depend on how exactly the commutator was defined to you( maybe your professor defined it through quotients, which would yield another simple solution)







                      share|cite|improve this answer














                      share|cite|improve this answer



                      share|cite|improve this answer








                      edited Jan 26 at 18:35

























                      answered Jan 25 at 18:17









                      Marat AlievMarat Aliev

                      1312




                      1312












                      • $begingroup$
                        I don't understand your formula for $[gb]$.
                        $endgroup$
                        – Yanko
                        Jan 25 at 19:36










                      • $begingroup$
                        Oh sorry i forgot the comma.
                        $endgroup$
                        – Marat Aliev
                        Jan 25 at 20:26










                      • $begingroup$
                        That's not that. I don't understand where the $c$'s come from.
                        $endgroup$
                        – Yanko
                        Jan 26 at 13:28






                      • 1




                        $begingroup$
                        Oh, sorry forgot that as well. the $c$ is to denote the generator of the cyclic group. Needs another edit, sorry for the mistype
                        $endgroup$
                        – Marat Aliev
                        Jan 26 at 18:35


















                      • $begingroup$
                        I don't understand your formula for $[gb]$.
                        $endgroup$
                        – Yanko
                        Jan 25 at 19:36










                      • $begingroup$
                        Oh sorry i forgot the comma.
                        $endgroup$
                        – Marat Aliev
                        Jan 25 at 20:26










                      • $begingroup$
                        That's not that. I don't understand where the $c$'s come from.
                        $endgroup$
                        – Yanko
                        Jan 26 at 13:28






                      • 1




                        $begingroup$
                        Oh, sorry forgot that as well. the $c$ is to denote the generator of the cyclic group. Needs another edit, sorry for the mistype
                        $endgroup$
                        – Marat Aliev
                        Jan 26 at 18:35
















                      $begingroup$
                      I don't understand your formula for $[gb]$.
                      $endgroup$
                      – Yanko
                      Jan 25 at 19:36




                      $begingroup$
                      I don't understand your formula for $[gb]$.
                      $endgroup$
                      – Yanko
                      Jan 25 at 19:36












                      $begingroup$
                      Oh sorry i forgot the comma.
                      $endgroup$
                      – Marat Aliev
                      Jan 25 at 20:26




                      $begingroup$
                      Oh sorry i forgot the comma.
                      $endgroup$
                      – Marat Aliev
                      Jan 25 at 20:26












                      $begingroup$
                      That's not that. I don't understand where the $c$'s come from.
                      $endgroup$
                      – Yanko
                      Jan 26 at 13:28




                      $begingroup$
                      That's not that. I don't understand where the $c$'s come from.
                      $endgroup$
                      – Yanko
                      Jan 26 at 13:28




                      1




                      1




                      $begingroup$
                      Oh, sorry forgot that as well. the $c$ is to denote the generator of the cyclic group. Needs another edit, sorry for the mistype
                      $endgroup$
                      – Marat Aliev
                      Jan 26 at 18:35




                      $begingroup$
                      Oh, sorry forgot that as well. the $c$ is to denote the generator of the cyclic group. Needs another edit, sorry for the mistype
                      $endgroup$
                      – Marat Aliev
                      Jan 26 at 18:35


















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