Product of gcd and lcm for multivariate polynomials












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This maybe trivial but I don't know how to conclude the proof. Consider the ring of multivariate polynomials with field coefficients $K[X_1,dots,X_n]$. Take two nonzero polynomials $F$ and $G$ and prove:



$$FG=gcd(F,G)lcm(F,G)$$



Since such ring is not Bezout I don't know how to prove this. I managed to prove that their gcd and their lcm both divide their product but I don't know how to do the converse relation.










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    1












    $begingroup$


    This maybe trivial but I don't know how to conclude the proof. Consider the ring of multivariate polynomials with field coefficients $K[X_1,dots,X_n]$. Take two nonzero polynomials $F$ and $G$ and prove:



    $$FG=gcd(F,G)lcm(F,G)$$



    Since such ring is not Bezout I don't know how to prove this. I managed to prove that their gcd and their lcm both divide their product but I don't know how to do the converse relation.










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      This maybe trivial but I don't know how to conclude the proof. Consider the ring of multivariate polynomials with field coefficients $K[X_1,dots,X_n]$. Take two nonzero polynomials $F$ and $G$ and prove:



      $$FG=gcd(F,G)lcm(F,G)$$



      Since such ring is not Bezout I don't know how to prove this. I managed to prove that their gcd and their lcm both divide their product but I don't know how to do the converse relation.










      share|cite|improve this question









      $endgroup$




      This maybe trivial but I don't know how to conclude the proof. Consider the ring of multivariate polynomials with field coefficients $K[X_1,dots,X_n]$. Take two nonzero polynomials $F$ and $G$ and prove:



      $$FG=gcd(F,G)lcm(F,G)$$



      Since such ring is not Bezout I don't know how to prove this. I managed to prove that their gcd and their lcm both divide their product but I don't know how to do the converse relation.







      polynomials commutative-algebra greatest-common-divisor least-common-multiple






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      asked Dec 6 '18 at 15:35









      Renato FaraoneRenato Faraone

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          $begingroup$

          The ring is a UFD so a GCD domain. As proved here the identity holds true in any GCD domain.



          It can also be proved via prime factorizations, but that is less general than said proof using gcd laws.






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            1 Answer
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            1












            $begingroup$

            The ring is a UFD so a GCD domain. As proved here the identity holds true in any GCD domain.



            It can also be proved via prime factorizations, but that is less general than said proof using gcd laws.






            share|cite|improve this answer









            $endgroup$


















              1












              $begingroup$

              The ring is a UFD so a GCD domain. As proved here the identity holds true in any GCD domain.



              It can also be proved via prime factorizations, but that is less general than said proof using gcd laws.






              share|cite|improve this answer









              $endgroup$
















                1












                1








                1





                $begingroup$

                The ring is a UFD so a GCD domain. As proved here the identity holds true in any GCD domain.



                It can also be proved via prime factorizations, but that is less general than said proof using gcd laws.






                share|cite|improve this answer









                $endgroup$



                The ring is a UFD so a GCD domain. As proved here the identity holds true in any GCD domain.



                It can also be proved via prime factorizations, but that is less general than said proof using gcd laws.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Dec 6 '18 at 15:41









                Bill DubuqueBill Dubuque

                209k29191639




                209k29191639






























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