Product of gcd and lcm for multivariate polynomials












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












    $begingroup$


    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






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Dec 6 '18 at 15:35









      Renato FaraoneRenato Faraone

      2,33111627




      2,33111627






















          1 Answer
          1






          active

          oldest

          votes


















          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









          $endgroup$













            Your Answer





            StackExchange.ifUsing("editor", function () {
            return StackExchange.using("mathjaxEditing", function () {
            StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
            StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
            });
            });
            }, "mathjax-editing");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "69"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            autoActivateHeartbeat: false,
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            noCode: true, onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3028637%2fproduct-of-gcd-and-lcm-for-multivariate-polynomials%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            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






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Mathematics Stack Exchange!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    Use MathJax to format equations. MathJax reference.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3028637%2fproduct-of-gcd-and-lcm-for-multivariate-polynomials%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    Ellipse (mathématiques)

                    Quarter-circle Tiles

                    Mont Emei