Uniform convergence of $sin(frac{x}{n}) , x>0$ [closed]











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I am having trouble in proving the uniform converge of $sin(frac{x}{n})$ for $x > 0$.










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closed as unclear what you're asking by gammatester, Bungo, T. Bongers, Jean-Claude Arbaut, Shailesh Nov 27 at 0:09


Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.















  • @hamam_Abdallah I have to prove it
    – Mikhail Terentyev
    Nov 26 at 18:37








  • 1




    Title and text are very different.
    – gammatester
    Nov 26 at 18:41










  • Welcome to Math StackExchange. Please explain your attempt at this and where you are stuck so that others can give an answer relevant to you.
    – Swapnil
    Nov 26 at 18:46










  • @gammatester It's my fault. I corrected question.
    – Mikhail Terentyev
    Nov 26 at 18:51






  • 1




    Sorry, but do you have any clue what you should do? How can you accept an answer, that does not handle your problem? This is your fault, because you edited the question in a way that it is now completely different. I voted to close the question.
    – gammatester
    Nov 26 at 19:25

















up vote
-3
down vote

favorite












I am having trouble in proving the uniform converge of $sin(frac{x}{n})$ for $x > 0$.










share|cite|improve this question















closed as unclear what you're asking by gammatester, Bungo, T. Bongers, Jean-Claude Arbaut, Shailesh Nov 27 at 0:09


Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.















  • @hamam_Abdallah I have to prove it
    – Mikhail Terentyev
    Nov 26 at 18:37








  • 1




    Title and text are very different.
    – gammatester
    Nov 26 at 18:41










  • Welcome to Math StackExchange. Please explain your attempt at this and where you are stuck so that others can give an answer relevant to you.
    – Swapnil
    Nov 26 at 18:46










  • @gammatester It's my fault. I corrected question.
    – Mikhail Terentyev
    Nov 26 at 18:51






  • 1




    Sorry, but do you have any clue what you should do? How can you accept an answer, that does not handle your problem? This is your fault, because you edited the question in a way that it is now completely different. I voted to close the question.
    – gammatester
    Nov 26 at 19:25















up vote
-3
down vote

favorite









up vote
-3
down vote

favorite











I am having trouble in proving the uniform converge of $sin(frac{x}{n})$ for $x > 0$.










share|cite|improve this question















I am having trouble in proving the uniform converge of $sin(frac{x}{n})$ for $x > 0$.







convergence






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share|cite|improve this question













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edited Nov 26 at 19:42









hamam_Abdallah

37.7k21634




37.7k21634










asked Nov 26 at 18:33









Mikhail Terentyev

32




32




closed as unclear what you're asking by gammatester, Bungo, T. Bongers, Jean-Claude Arbaut, Shailesh Nov 27 at 0:09


Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.






closed as unclear what you're asking by gammatester, Bungo, T. Bongers, Jean-Claude Arbaut, Shailesh Nov 27 at 0:09


Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.














  • @hamam_Abdallah I have to prove it
    – Mikhail Terentyev
    Nov 26 at 18:37








  • 1




    Title and text are very different.
    – gammatester
    Nov 26 at 18:41










  • Welcome to Math StackExchange. Please explain your attempt at this and where you are stuck so that others can give an answer relevant to you.
    – Swapnil
    Nov 26 at 18:46










  • @gammatester It's my fault. I corrected question.
    – Mikhail Terentyev
    Nov 26 at 18:51






  • 1




    Sorry, but do you have any clue what you should do? How can you accept an answer, that does not handle your problem? This is your fault, because you edited the question in a way that it is now completely different. I voted to close the question.
    – gammatester
    Nov 26 at 19:25




















  • @hamam_Abdallah I have to prove it
    – Mikhail Terentyev
    Nov 26 at 18:37








  • 1




    Title and text are very different.
    – gammatester
    Nov 26 at 18:41










  • Welcome to Math StackExchange. Please explain your attempt at this and where you are stuck so that others can give an answer relevant to you.
    – Swapnil
    Nov 26 at 18:46










  • @gammatester It's my fault. I corrected question.
    – Mikhail Terentyev
    Nov 26 at 18:51






  • 1




    Sorry, but do you have any clue what you should do? How can you accept an answer, that does not handle your problem? This is your fault, because you edited the question in a way that it is now completely different. I voted to close the question.
    – gammatester
    Nov 26 at 19:25


















@hamam_Abdallah I have to prove it
– Mikhail Terentyev
Nov 26 at 18:37






@hamam_Abdallah I have to prove it
– Mikhail Terentyev
Nov 26 at 18:37






1




1




Title and text are very different.
– gammatester
Nov 26 at 18:41




Title and text are very different.
– gammatester
Nov 26 at 18:41












Welcome to Math StackExchange. Please explain your attempt at this and where you are stuck so that others can give an answer relevant to you.
– Swapnil
Nov 26 at 18:46




Welcome to Math StackExchange. Please explain your attempt at this and where you are stuck so that others can give an answer relevant to you.
– Swapnil
Nov 26 at 18:46












@gammatester It's my fault. I corrected question.
– Mikhail Terentyev
Nov 26 at 18:51




@gammatester It's my fault. I corrected question.
– Mikhail Terentyev
Nov 26 at 18:51




1




1




Sorry, but do you have any clue what you should do? How can you accept an answer, that does not handle your problem? This is your fault, because you edited the question in a way that it is now completely different. I voted to close the question.
– gammatester
Nov 26 at 19:25






Sorry, but do you have any clue what you should do? How can you accept an answer, that does not handle your problem? This is your fault, because you edited the question in a way that it is now completely different. I voted to close the question.
– gammatester
Nov 26 at 19:25












1 Answer
1






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oldest

votes

















up vote
0
down vote



accepted










We know that for $X>0,$ we have



$$|sin(X)|le X$$



thus for $x>0$ and $n>0$



$$|sin(frac{x}{n})|le frac xn$$



but
$$lim_{nto+infty}frac xn=0$$



therefore



$$lim_{nto+infty}sin(frac xn)=0$$



the convergence is uniform at $[0,a]$ but not at $[0,+infty)$ if you take $x_n=nfrac pi 2$.






share|cite|improve this answer






























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    0
    down vote



    accepted










    We know that for $X>0,$ we have



    $$|sin(X)|le X$$



    thus for $x>0$ and $n>0$



    $$|sin(frac{x}{n})|le frac xn$$



    but
    $$lim_{nto+infty}frac xn=0$$



    therefore



    $$lim_{nto+infty}sin(frac xn)=0$$



    the convergence is uniform at $[0,a]$ but not at $[0,+infty)$ if you take $x_n=nfrac pi 2$.






    share|cite|improve this answer



























      up vote
      0
      down vote



      accepted










      We know that for $X>0,$ we have



      $$|sin(X)|le X$$



      thus for $x>0$ and $n>0$



      $$|sin(frac{x}{n})|le frac xn$$



      but
      $$lim_{nto+infty}frac xn=0$$



      therefore



      $$lim_{nto+infty}sin(frac xn)=0$$



      the convergence is uniform at $[0,a]$ but not at $[0,+infty)$ if you take $x_n=nfrac pi 2$.






      share|cite|improve this answer

























        up vote
        0
        down vote



        accepted







        up vote
        0
        down vote



        accepted






        We know that for $X>0,$ we have



        $$|sin(X)|le X$$



        thus for $x>0$ and $n>0$



        $$|sin(frac{x}{n})|le frac xn$$



        but
        $$lim_{nto+infty}frac xn=0$$



        therefore



        $$lim_{nto+infty}sin(frac xn)=0$$



        the convergence is uniform at $[0,a]$ but not at $[0,+infty)$ if you take $x_n=nfrac pi 2$.






        share|cite|improve this answer














        We know that for $X>0,$ we have



        $$|sin(X)|le X$$



        thus for $x>0$ and $n>0$



        $$|sin(frac{x}{n})|le frac xn$$



        but
        $$lim_{nto+infty}frac xn=0$$



        therefore



        $$lim_{nto+infty}sin(frac xn)=0$$



        the convergence is uniform at $[0,a]$ but not at $[0,+infty)$ if you take $x_n=nfrac pi 2$.







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Nov 26 at 19:36

























        answered Nov 26 at 18:41









        hamam_Abdallah

        37.7k21634




        37.7k21634















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