construct a continuous function which vanishes at infinity











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I want to construct a continuous function $f$ on $mathbb{C}$ such that $f(0)=0 $ and $f$ vanishes at infinity.Can anyone give me some examples,thanks!










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  • 3




    $f(z)=dfrac{z}{e^z}$
    – Yadati Kiran
    Nov 18 at 10:51










  • This example is wrong. $f(2npi i)=2npi i $ which does not tend to $0$.
    – Kavi Rama Murthy
    Nov 18 at 11:53










  • What about $f(z) = 0$?
    – gerw
    Nov 18 at 19:28















up vote
-1
down vote

favorite












I want to construct a continuous function $f$ on $mathbb{C}$ such that $f(0)=0 $ and $f$ vanishes at infinity.Can anyone give me some examples,thanks!










share|cite|improve this question


















  • 3




    $f(z)=dfrac{z}{e^z}$
    – Yadati Kiran
    Nov 18 at 10:51










  • This example is wrong. $f(2npi i)=2npi i $ which does not tend to $0$.
    – Kavi Rama Murthy
    Nov 18 at 11:53










  • What about $f(z) = 0$?
    – gerw
    Nov 18 at 19:28













up vote
-1
down vote

favorite









up vote
-1
down vote

favorite











I want to construct a continuous function $f$ on $mathbb{C}$ such that $f(0)=0 $ and $f$ vanishes at infinity.Can anyone give me some examples,thanks!










share|cite|improve this question













I want to construct a continuous function $f$ on $mathbb{C}$ such that $f(0)=0 $ and $f$ vanishes at infinity.Can anyone give me some examples,thanks!







calculus complex-analysis functional-analysis functions






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asked Nov 18 at 10:48









mathrookie

709512




709512








  • 3




    $f(z)=dfrac{z}{e^z}$
    – Yadati Kiran
    Nov 18 at 10:51










  • This example is wrong. $f(2npi i)=2npi i $ which does not tend to $0$.
    – Kavi Rama Murthy
    Nov 18 at 11:53










  • What about $f(z) = 0$?
    – gerw
    Nov 18 at 19:28














  • 3




    $f(z)=dfrac{z}{e^z}$
    – Yadati Kiran
    Nov 18 at 10:51










  • This example is wrong. $f(2npi i)=2npi i $ which does not tend to $0$.
    – Kavi Rama Murthy
    Nov 18 at 11:53










  • What about $f(z) = 0$?
    – gerw
    Nov 18 at 19:28








3




3




$f(z)=dfrac{z}{e^z}$
– Yadati Kiran
Nov 18 at 10:51




$f(z)=dfrac{z}{e^z}$
– Yadati Kiran
Nov 18 at 10:51












This example is wrong. $f(2npi i)=2npi i $ which does not tend to $0$.
– Kavi Rama Murthy
Nov 18 at 11:53




This example is wrong. $f(2npi i)=2npi i $ which does not tend to $0$.
– Kavi Rama Murthy
Nov 18 at 11:53












What about $f(z) = 0$?
– gerw
Nov 18 at 19:28




What about $f(z) = 0$?
– gerw
Nov 18 at 19:28










1 Answer
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2
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accepted










$f(z)=z$ for $|z| <1$, $f(z)=frac z {|z|^{2}}$ if $|z| geq 1$.






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    1 Answer
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    active

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    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    2
    down vote



    accepted










    $f(z)=z$ for $|z| <1$, $f(z)=frac z {|z|^{2}}$ if $|z| geq 1$.






    share|cite|improve this answer

























      up vote
      2
      down vote



      accepted










      $f(z)=z$ for $|z| <1$, $f(z)=frac z {|z|^{2}}$ if $|z| geq 1$.






      share|cite|improve this answer























        up vote
        2
        down vote



        accepted







        up vote
        2
        down vote



        accepted






        $f(z)=z$ for $|z| <1$, $f(z)=frac z {|z|^{2}}$ if $|z| geq 1$.






        share|cite|improve this answer












        $f(z)=z$ for $|z| <1$, $f(z)=frac z {|z|^{2}}$ if $|z| geq 1$.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 18 at 11:56









        Kavi Rama Murthy

        41.7k31751




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