Proof that for every Meromorphic function, it`s derevative is also Meromorphic












0












$begingroup$


for $f(z)$ Meromorphic we know that $f(z)$ on $Omega$ - an open set ,is Holomorphic on $Omega/A$ when $A$ is discrete set of the poles of $f(z)$.



I know that $f'(z)$ is also Holomorphic on $Omega/A$ because $f(z)$ analytic on this set.
Would it be enough to write $f(z)=frac {g(z)}{h(z)}$ and $g(z),h(z)$ are holomorphic functions on $Bbb C$, and then $f'(z)=frac {g'(z)h(z)-g(z)h'(z)}{(h(z))^2}$
so we know that the set of zeros of $f(z), f'(z)$ denominator is the same, so we know this set is A and it's elements are poles for $f(z)$ and $f'(z)$?










share|cite|improve this question









$endgroup$

















    0












    $begingroup$


    for $f(z)$ Meromorphic we know that $f(z)$ on $Omega$ - an open set ,is Holomorphic on $Omega/A$ when $A$ is discrete set of the poles of $f(z)$.



    I know that $f'(z)$ is also Holomorphic on $Omega/A$ because $f(z)$ analytic on this set.
    Would it be enough to write $f(z)=frac {g(z)}{h(z)}$ and $g(z),h(z)$ are holomorphic functions on $Bbb C$, and then $f'(z)=frac {g'(z)h(z)-g(z)h'(z)}{(h(z))^2}$
    so we know that the set of zeros of $f(z), f'(z)$ denominator is the same, so we know this set is A and it's elements are poles for $f(z)$ and $f'(z)$?










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      for $f(z)$ Meromorphic we know that $f(z)$ on $Omega$ - an open set ,is Holomorphic on $Omega/A$ when $A$ is discrete set of the poles of $f(z)$.



      I know that $f'(z)$ is also Holomorphic on $Omega/A$ because $f(z)$ analytic on this set.
      Would it be enough to write $f(z)=frac {g(z)}{h(z)}$ and $g(z),h(z)$ are holomorphic functions on $Bbb C$, and then $f'(z)=frac {g'(z)h(z)-g(z)h'(z)}{(h(z))^2}$
      so we know that the set of zeros of $f(z), f'(z)$ denominator is the same, so we know this set is A and it's elements are poles for $f(z)$ and $f'(z)$?










      share|cite|improve this question









      $endgroup$




      for $f(z)$ Meromorphic we know that $f(z)$ on $Omega$ - an open set ,is Holomorphic on $Omega/A$ when $A$ is discrete set of the poles of $f(z)$.



      I know that $f'(z)$ is also Holomorphic on $Omega/A$ because $f(z)$ analytic on this set.
      Would it be enough to write $f(z)=frac {g(z)}{h(z)}$ and $g(z),h(z)$ are holomorphic functions on $Bbb C$, and then $f'(z)=frac {g'(z)h(z)-g(z)h'(z)}{(h(z))^2}$
      so we know that the set of zeros of $f(z), f'(z)$ denominator is the same, so we know this set is A and it's elements are poles for $f(z)$ and $f'(z)$?







      complex-analysis meromorphic-functions






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Dec 4 '18 at 11:50









      Daniel VainshteinDaniel Vainshtein

      19011




      19011






















          1 Answer
          1






          active

          oldest

          votes


















          0












          $begingroup$

          Yes, that would be enough. When you differentiate a meromorphic function, your are not adding any new poles, and the original poels remain poles (that is, they don't become essential singularities).






          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%2f3025470%2fproof-that-for-every-meromorphic-function-its-derevative-is-also-meromorphic%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









            0












            $begingroup$

            Yes, that would be enough. When you differentiate a meromorphic function, your are not adding any new poles, and the original poels remain poles (that is, they don't become essential singularities).






            share|cite|improve this answer









            $endgroup$


















              0












              $begingroup$

              Yes, that would be enough. When you differentiate a meromorphic function, your are not adding any new poles, and the original poels remain poles (that is, they don't become essential singularities).






              share|cite|improve this answer









              $endgroup$
















                0












                0








                0





                $begingroup$

                Yes, that would be enough. When you differentiate a meromorphic function, your are not adding any new poles, and the original poels remain poles (that is, they don't become essential singularities).






                share|cite|improve this answer









                $endgroup$



                Yes, that would be enough. When you differentiate a meromorphic function, your are not adding any new poles, and the original poels remain poles (that is, they don't become essential singularities).







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Dec 4 '18 at 11:52









                José Carlos SantosJosé Carlos Santos

                158k22126228




                158k22126228






























                    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%2f3025470%2fproof-that-for-every-meromorphic-function-its-derevative-is-also-meromorphic%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

                    Plaza Victoria

                    In PowerPoint, is there a keyboard shortcut for bulleted / numbered list?

                    How to put 3 figures in Latex with 2 figures side by side and 1 below these side by side images but in...