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












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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 $f'(z)$?










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    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






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      asked Dec 4 '18 at 11:50









      Daniel VainshteinDaniel Vainshtein

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          $begingroup$

          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).






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            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

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