C($mathbb{R}$) is complete under the discrete metric.












0












$begingroup$


Examine if the space $X=C(mathbb{R})$ endowed with the discrete metric $d_0$ is complete or not.



We know that $(X,d_0)$ is complete if every Cauchy sequence is finally constant. We want to construct a function $f(x_n),Cauchy$ such that $f(x_n)rightarrow f(x_0)$ and also $f$ is continuous.



Is this gonna work?










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    Examine if the space $X=C(mathbb{R})$ endowed with the discrete metric $d_0$ is complete or not.



    We know that $(X,d_0)$ is complete if every Cauchy sequence is finally constant. We want to construct a function $f(x_n),Cauchy$ such that $f(x_n)rightarrow f(x_0)$ and also $f$ is continuous.



    Is this gonna work?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Examine if the space $X=C(mathbb{R})$ endowed with the discrete metric $d_0$ is complete or not.



      We know that $(X,d_0)$ is complete if every Cauchy sequence is finally constant. We want to construct a function $f(x_n),Cauchy$ such that $f(x_n)rightarrow f(x_0)$ and also $f$ is continuous.



      Is this gonna work?










      share|cite|improve this question











      $endgroup$




      Examine if the space $X=C(mathbb{R})$ endowed with the discrete metric $d_0$ is complete or not.



      We know that $(X,d_0)$ is complete if every Cauchy sequence is finally constant. We want to construct a function $f(x_n),Cauchy$ such that $f(x_n)rightarrow f(x_0)$ and also $f$ is continuous.



      Is this gonna work?







      metric-spaces cauchy-sequences complete-spaces






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 7 at 13:49









      José Carlos Santos

      153k22123225




      153k22123225










      asked Oct 11 '18 at 11:29









      argiriskarargiriskar

      1409




      1409






















          1 Answer
          1






          active

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          5












          $begingroup$

          If you endow any set with that discrete metric, it becomes a complete metric space, because any Cauchy sequence is constant then, if $n$ is large enough.






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            I don't know if i used the right word because i tranlated the problem from Greek. But it basically asks you to prove that C($mathbb{R}$),$d_0$) is complete or not.
            $endgroup$
            – argiriskar
            Oct 11 '18 at 11:36












          • $begingroup$
            This post answers your question. In order for a metric space to be complete, every Cauchy sequence must converges (with respect to the metric defined on the space). Every Cauchy sequence in your space must be constant for $n$ large enough, so it converges.
            $endgroup$
            – nicomezi
            Oct 11 '18 at 11:42











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          1 Answer
          1






          active

          oldest

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          active

          oldest

          votes






          active

          oldest

          votes









          5












          $begingroup$

          If you endow any set with that discrete metric, it becomes a complete metric space, because any Cauchy sequence is constant then, if $n$ is large enough.






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            I don't know if i used the right word because i tranlated the problem from Greek. But it basically asks you to prove that C($mathbb{R}$),$d_0$) is complete or not.
            $endgroup$
            – argiriskar
            Oct 11 '18 at 11:36












          • $begingroup$
            This post answers your question. In order for a metric space to be complete, every Cauchy sequence must converges (with respect to the metric defined on the space). Every Cauchy sequence in your space must be constant for $n$ large enough, so it converges.
            $endgroup$
            – nicomezi
            Oct 11 '18 at 11:42
















          5












          $begingroup$

          If you endow any set with that discrete metric, it becomes a complete metric space, because any Cauchy sequence is constant then, if $n$ is large enough.






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            I don't know if i used the right word because i tranlated the problem from Greek. But it basically asks you to prove that C($mathbb{R}$),$d_0$) is complete or not.
            $endgroup$
            – argiriskar
            Oct 11 '18 at 11:36












          • $begingroup$
            This post answers your question. In order for a metric space to be complete, every Cauchy sequence must converges (with respect to the metric defined on the space). Every Cauchy sequence in your space must be constant for $n$ large enough, so it converges.
            $endgroup$
            – nicomezi
            Oct 11 '18 at 11:42














          5












          5








          5





          $begingroup$

          If you endow any set with that discrete metric, it becomes a complete metric space, because any Cauchy sequence is constant then, if $n$ is large enough.






          share|cite|improve this answer











          $endgroup$



          If you endow any set with that discrete metric, it becomes a complete metric space, because any Cauchy sequence is constant then, if $n$ is large enough.







          share|cite|improve this answer














          share|cite|improve this answer



          share|cite|improve this answer








          edited Jan 7 at 13:48

























          answered Oct 11 '18 at 11:31









          José Carlos SantosJosé Carlos Santos

          153k22123225




          153k22123225












          • $begingroup$
            I don't know if i used the right word because i tranlated the problem from Greek. But it basically asks you to prove that C($mathbb{R}$),$d_0$) is complete or not.
            $endgroup$
            – argiriskar
            Oct 11 '18 at 11:36












          • $begingroup$
            This post answers your question. In order for a metric space to be complete, every Cauchy sequence must converges (with respect to the metric defined on the space). Every Cauchy sequence in your space must be constant for $n$ large enough, so it converges.
            $endgroup$
            – nicomezi
            Oct 11 '18 at 11:42


















          • $begingroup$
            I don't know if i used the right word because i tranlated the problem from Greek. But it basically asks you to prove that C($mathbb{R}$),$d_0$) is complete or not.
            $endgroup$
            – argiriskar
            Oct 11 '18 at 11:36












          • $begingroup$
            This post answers your question. In order for a metric space to be complete, every Cauchy sequence must converges (with respect to the metric defined on the space). Every Cauchy sequence in your space must be constant for $n$ large enough, so it converges.
            $endgroup$
            – nicomezi
            Oct 11 '18 at 11:42
















          $begingroup$
          I don't know if i used the right word because i tranlated the problem from Greek. But it basically asks you to prove that C($mathbb{R}$),$d_0$) is complete or not.
          $endgroup$
          – argiriskar
          Oct 11 '18 at 11:36






          $begingroup$
          I don't know if i used the right word because i tranlated the problem from Greek. But it basically asks you to prove that C($mathbb{R}$),$d_0$) is complete or not.
          $endgroup$
          – argiriskar
          Oct 11 '18 at 11:36














          $begingroup$
          This post answers your question. In order for a metric space to be complete, every Cauchy sequence must converges (with respect to the metric defined on the space). Every Cauchy sequence in your space must be constant for $n$ large enough, so it converges.
          $endgroup$
          – nicomezi
          Oct 11 '18 at 11:42




          $begingroup$
          This post answers your question. In order for a metric space to be complete, every Cauchy sequence must converges (with respect to the metric defined on the space). Every Cauchy sequence in your space must be constant for $n$ large enough, so it converges.
          $endgroup$
          – nicomezi
          Oct 11 '18 at 11:42


















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