exercise on convergent sequences The Next CEO of Stack OverflowCompleteness and Cauchy SequencesBounded sequence and every convergent subsequence converges to LProve that a metric space is countably compact if and only if every infinite sequence in $X$ has a convergent subsequence.Prove that if every PROPER sub sequence of a sequence is convergent , then the sequence is convergentSequence of elements having a convergent subsequence -NBHM $2014$Convergent sequences out of bounded sequencesBolzano-Weierstrass for metric spacesA map between metric spaces preserving convergent sequences is continuousConvergent sequences in a metric spaceConvergent and Cauchy sequences in metric spaces

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exercise on convergent sequences



The Next CEO of Stack OverflowCompleteness and Cauchy SequencesBounded sequence and every convergent subsequence converges to LProve that a metric space is countably compact if and only if every infinite sequence in $X$ has a convergent subsequence.Prove that if every PROPER sub sequence of a sequence is convergent , then the sequence is convergentSequence of elements having a convergent subsequence -NBHM $2014$Convergent sequences out of bounded sequencesBolzano-Weierstrass for metric spacesA map between metric spaces preserving convergent sequences is continuousConvergent sequences in a metric spaceConvergent and Cauchy sequences in metric spaces










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How can I prove that a sequence in a metric space converges to an element iff every sub-sequence has a sub-sub-sequence convergent to that element.
Thank for the help!!










share|cite|improve this question











$endgroup$











  • $begingroup$
    I think "succession" should be "sequence".
    $endgroup$
    – zhw.
    Mar 18 at 18:42















0












$begingroup$


How can I prove that a sequence in a metric space converges to an element iff every sub-sequence has a sub-sub-sequence convergent to that element.
Thank for the help!!










share|cite|improve this question











$endgroup$











  • $begingroup$
    I think "succession" should be "sequence".
    $endgroup$
    – zhw.
    Mar 18 at 18:42













0












0








0





$begingroup$


How can I prove that a sequence in a metric space converges to an element iff every sub-sequence has a sub-sub-sequence convergent to that element.
Thank for the help!!










share|cite|improve this question











$endgroup$




How can I prove that a sequence in a metric space converges to an element iff every sub-sequence has a sub-sub-sequence convergent to that element.
Thank for the help!!







real-analysis analysis convergence metric-spaces






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Mar 19 at 10:12







Alessandro Pecile

















asked Mar 18 at 16:05









Alessandro PecileAlessandro Pecile

755




755











  • $begingroup$
    I think "succession" should be "sequence".
    $endgroup$
    – zhw.
    Mar 18 at 18:42
















  • $begingroup$
    I think "succession" should be "sequence".
    $endgroup$
    – zhw.
    Mar 18 at 18:42















$begingroup$
I think "succession" should be "sequence".
$endgroup$
– zhw.
Mar 18 at 18:42




$begingroup$
I think "succession" should be "sequence".
$endgroup$
– zhw.
Mar 18 at 18:42










1 Answer
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Hint: If $x_n$ does not converge to $L,$ then for some $epsilon>0,$ there is no $N$ such that $nge N$ implies $d(x_n,L) <epsilon.$ Argue that this implies there is a subsequence $x_n_k$ such that $d(x_n_k,L) geepsilon$ for all $k.$






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    1 Answer
    1






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    active

    oldest

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    1












    $begingroup$

    Hint: If $x_n$ does not converge to $L,$ then for some $epsilon>0,$ there is no $N$ such that $nge N$ implies $d(x_n,L) <epsilon.$ Argue that this implies there is a subsequence $x_n_k$ such that $d(x_n_k,L) geepsilon$ for all $k.$






    share|cite|improve this answer









    $endgroup$

















      1












      $begingroup$

      Hint: If $x_n$ does not converge to $L,$ then for some $epsilon>0,$ there is no $N$ such that $nge N$ implies $d(x_n,L) <epsilon.$ Argue that this implies there is a subsequence $x_n_k$ such that $d(x_n_k,L) geepsilon$ for all $k.$






      share|cite|improve this answer









      $endgroup$















        1












        1








        1





        $begingroup$

        Hint: If $x_n$ does not converge to $L,$ then for some $epsilon>0,$ there is no $N$ such that $nge N$ implies $d(x_n,L) <epsilon.$ Argue that this implies there is a subsequence $x_n_k$ such that $d(x_n_k,L) geepsilon$ for all $k.$






        share|cite|improve this answer









        $endgroup$



        Hint: If $x_n$ does not converge to $L,$ then for some $epsilon>0,$ there is no $N$ such that $nge N$ implies $d(x_n,L) <epsilon.$ Argue that this implies there is a subsequence $x_n_k$ such that $d(x_n_k,L) geepsilon$ for all $k.$







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Mar 18 at 18:49









        zhw.zhw.

        74.8k43175




        74.8k43175



























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