Using the $varepsilon − N$ definition of the limit, prove that $lim limits_ntoinfty frac(n^2 + 1) (n^2 + 2) = 1$.Use the $varepsilon$-$delta$ definition of a limit to prove this.Prove limit doesn't exist using $delta$-$varepsilon$Can we prove that there is no limit at $x=0$ for $f(x)=1/x$ using epsilon-delta definition?Directly prove using the definition of convergence $limlimits_n to inftyfracn^2 +1 4n -1 = infty$How to prove $limlimits_nto infty(a_n+2b_n)=L+2M$ using the formal definition of limit of sequence?How to write $varepsilon$–$delta$ definition of $limlimits_ntoinftyf(a_n)=f(c)$?Proving the limit of $frac1n^2+n$ = 0 using the $epsilon$ - N definitionFormal limit definition in $limlimits_xto+infty fracx^2+29x=+infty$What exactly does the $varepsilon$-$delta$ definition of limits prove?Prove that the sequence converges to using the $varepsilon$-$N$ definition of a limit

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Using the $varepsilon − N$ definition of the limit, prove that $lim limits_ntoinfty frac(n^2 + 1) (n^2 + 2) = 1$.


Use the $varepsilon$-$delta$ definition of a limit to prove this.Prove limit doesn't exist using $delta$-$varepsilon$Can we prove that there is no limit at $x=0$ for $f(x)=1/x$ using epsilon-delta definition?Directly prove using the definition of convergence $limlimits_n to inftyfracn^2 +1 4n -1 = infty$How to prove $limlimits_nto infty(a_n+2b_n)=L+2M$ using the formal definition of limit of sequence?How to write $varepsilon$–$delta$ definition of $limlimits_ntoinftyf(a_n)=f(c)$?Proving the limit of $frac1n^2+n$ = 0 using the $epsilon$ - N definitionFormal limit definition in $limlimits_xto+infty fracx^2+29x=+infty$What exactly does the $varepsilon$-$delta$ definition of limits prove?Prove that the sequence converges to using the $varepsilon$-$N$ definition of a limit













-1












$begingroup$



Using the $ε − N$ definition of the limit, prove that
$displaystylelim limits_ntoinfty frac(n^2 + 1) (n^2 + 2) = 1$.




In other words, given $varepsilon> 0$, find explicitly a natural number $N$ which
satisfies the statement in the definition of the limit.










share|cite|improve this question









New contributor




john smith is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    What have you tried?
    $endgroup$
    – Kezer
    Mar 13 at 10:48










  • $begingroup$
    trying to divide top and bottom by n^2 but dont know what to do now
    $endgroup$
    – john smith
    Mar 13 at 10:51






  • 1




    $begingroup$
    Perhaps start by writing out the definition.
    $endgroup$
    – Kezer
    Mar 13 at 10:53










  • $begingroup$
    is that the epsilon >0 thing, then I say n> N?
    $endgroup$
    – john smith
    Mar 13 at 10:55










  • $begingroup$
    Yes, that's it.
    $endgroup$
    – frabala
    Mar 13 at 11:10















-1












$begingroup$



Using the $ε − N$ definition of the limit, prove that
$displaystylelim limits_ntoinfty frac(n^2 + 1) (n^2 + 2) = 1$.




In other words, given $varepsilon> 0$, find explicitly a natural number $N$ which
satisfies the statement in the definition of the limit.










share|cite|improve this question









New contributor




john smith is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    What have you tried?
    $endgroup$
    – Kezer
    Mar 13 at 10:48










  • $begingroup$
    trying to divide top and bottom by n^2 but dont know what to do now
    $endgroup$
    – john smith
    Mar 13 at 10:51






  • 1




    $begingroup$
    Perhaps start by writing out the definition.
    $endgroup$
    – Kezer
    Mar 13 at 10:53










  • $begingroup$
    is that the epsilon >0 thing, then I say n> N?
    $endgroup$
    – john smith
    Mar 13 at 10:55










  • $begingroup$
    Yes, that's it.
    $endgroup$
    – frabala
    Mar 13 at 11:10













-1












-1








-1





$begingroup$



Using the $ε − N$ definition of the limit, prove that
$displaystylelim limits_ntoinfty frac(n^2 + 1) (n^2 + 2) = 1$.




In other words, given $varepsilon> 0$, find explicitly a natural number $N$ which
satisfies the statement in the definition of the limit.










share|cite|improve this question









New contributor




john smith is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$





Using the $ε − N$ definition of the limit, prove that
$displaystylelim limits_ntoinfty frac(n^2 + 1) (n^2 + 2) = 1$.




In other words, given $varepsilon> 0$, find explicitly a natural number $N$ which
satisfies the statement in the definition of the limit.







limits epsilon-delta






share|cite|improve this question









New contributor




john smith is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|cite|improve this question









New contributor




john smith is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|cite|improve this question




share|cite|improve this question








edited Mar 13 at 10:57









Yadati Kiran

2,1061621




2,1061621






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asked Mar 13 at 10:40









john smithjohn smith

64




64




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john smith is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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  • 1




    $begingroup$
    What have you tried?
    $endgroup$
    – Kezer
    Mar 13 at 10:48










  • $begingroup$
    trying to divide top and bottom by n^2 but dont know what to do now
    $endgroup$
    – john smith
    Mar 13 at 10:51






  • 1




    $begingroup$
    Perhaps start by writing out the definition.
    $endgroup$
    – Kezer
    Mar 13 at 10:53










  • $begingroup$
    is that the epsilon >0 thing, then I say n> N?
    $endgroup$
    – john smith
    Mar 13 at 10:55










  • $begingroup$
    Yes, that's it.
    $endgroup$
    – frabala
    Mar 13 at 11:10












  • 1




    $begingroup$
    What have you tried?
    $endgroup$
    – Kezer
    Mar 13 at 10:48










  • $begingroup$
    trying to divide top and bottom by n^2 but dont know what to do now
    $endgroup$
    – john smith
    Mar 13 at 10:51






  • 1




    $begingroup$
    Perhaps start by writing out the definition.
    $endgroup$
    – Kezer
    Mar 13 at 10:53










  • $begingroup$
    is that the epsilon >0 thing, then I say n> N?
    $endgroup$
    – john smith
    Mar 13 at 10:55










  • $begingroup$
    Yes, that's it.
    $endgroup$
    – frabala
    Mar 13 at 11:10







1




1




$begingroup$
What have you tried?
$endgroup$
– Kezer
Mar 13 at 10:48




$begingroup$
What have you tried?
$endgroup$
– Kezer
Mar 13 at 10:48












$begingroup$
trying to divide top and bottom by n^2 but dont know what to do now
$endgroup$
– john smith
Mar 13 at 10:51




$begingroup$
trying to divide top and bottom by n^2 but dont know what to do now
$endgroup$
– john smith
Mar 13 at 10:51




1




1




$begingroup$
Perhaps start by writing out the definition.
$endgroup$
– Kezer
Mar 13 at 10:53




$begingroup$
Perhaps start by writing out the definition.
$endgroup$
– Kezer
Mar 13 at 10:53












$begingroup$
is that the epsilon >0 thing, then I say n> N?
$endgroup$
– john smith
Mar 13 at 10:55




$begingroup$
is that the epsilon >0 thing, then I say n> N?
$endgroup$
– john smith
Mar 13 at 10:55












$begingroup$
Yes, that's it.
$endgroup$
– frabala
Mar 13 at 11:10




$begingroup$
Yes, that's it.
$endgroup$
– frabala
Mar 13 at 11:10










3 Answers
3






active

oldest

votes


















0












$begingroup$

Let $varepsilon > 0$.



Define $$N = lfloor sqrtfrac1varepsilon-2rfloor +1$$



For all $n geq N$, you have then $$n geq sqrtfrac1varepsilon-2$$
so
$$n^2+2 geq frac1varepsilon$$



so $$frac1n^2+2 leq varepsilon$$



so
$$left| fracn^2+1n^2+2 - 1 right| leq varepsilon$$



By the definition of the limit, this shows that
$$fracn^2+1n^2+2 rightarrow 1 $$






share|cite|improve this answer









$endgroup$




















    0












    $begingroup$

    $$|a_n-1|=1over n^2+2$$therefore if $n>1over sqrtepsilon$ we obtain $$n^2+2>1over epsilon+2>1over epsilon$$and $$|a_n-1|<epsilon$$ hence the result.






    share|cite|improve this answer









    $endgroup$




















      0












      $begingroup$

      First of all rewrite the expression:
      $a_n := fracn^2+1n^2+2 = 1-frac1n^2+2$.



      Choose $N in mathbbN$ and let $n geq N$. Then we have:



      $ Big | a_n -1 Big | = frac1n^2+2 leq frac1n^2 leq frac1N^2$



      Do you have an idea how to choose $N in mathbbN$ from this inequality?






      share|cite|improve this answer










      New contributor




      GordonFreeman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      $endgroup$












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        3 Answers
        3






        active

        oldest

        votes








        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        0












        $begingroup$

        Let $varepsilon > 0$.



        Define $$N = lfloor sqrtfrac1varepsilon-2rfloor +1$$



        For all $n geq N$, you have then $$n geq sqrtfrac1varepsilon-2$$
        so
        $$n^2+2 geq frac1varepsilon$$



        so $$frac1n^2+2 leq varepsilon$$



        so
        $$left| fracn^2+1n^2+2 - 1 right| leq varepsilon$$



        By the definition of the limit, this shows that
        $$fracn^2+1n^2+2 rightarrow 1 $$






        share|cite|improve this answer









        $endgroup$

















          0












          $begingroup$

          Let $varepsilon > 0$.



          Define $$N = lfloor sqrtfrac1varepsilon-2rfloor +1$$



          For all $n geq N$, you have then $$n geq sqrtfrac1varepsilon-2$$
          so
          $$n^2+2 geq frac1varepsilon$$



          so $$frac1n^2+2 leq varepsilon$$



          so
          $$left| fracn^2+1n^2+2 - 1 right| leq varepsilon$$



          By the definition of the limit, this shows that
          $$fracn^2+1n^2+2 rightarrow 1 $$






          share|cite|improve this answer









          $endgroup$















            0












            0








            0





            $begingroup$

            Let $varepsilon > 0$.



            Define $$N = lfloor sqrtfrac1varepsilon-2rfloor +1$$



            For all $n geq N$, you have then $$n geq sqrtfrac1varepsilon-2$$
            so
            $$n^2+2 geq frac1varepsilon$$



            so $$frac1n^2+2 leq varepsilon$$



            so
            $$left| fracn^2+1n^2+2 - 1 right| leq varepsilon$$



            By the definition of the limit, this shows that
            $$fracn^2+1n^2+2 rightarrow 1 $$






            share|cite|improve this answer









            $endgroup$



            Let $varepsilon > 0$.



            Define $$N = lfloor sqrtfrac1varepsilon-2rfloor +1$$



            For all $n geq N$, you have then $$n geq sqrtfrac1varepsilon-2$$
            so
            $$n^2+2 geq frac1varepsilon$$



            so $$frac1n^2+2 leq varepsilon$$



            so
            $$left| fracn^2+1n^2+2 - 1 right| leq varepsilon$$



            By the definition of the limit, this shows that
            $$fracn^2+1n^2+2 rightarrow 1 $$







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Mar 13 at 11:48









            TheSilverDoeTheSilverDoe

            4,085114




            4,085114





















                0












                $begingroup$

                $$|a_n-1|=1over n^2+2$$therefore if $n>1over sqrtepsilon$ we obtain $$n^2+2>1over epsilon+2>1over epsilon$$and $$|a_n-1|<epsilon$$ hence the result.






                share|cite|improve this answer









                $endgroup$

















                  0












                  $begingroup$

                  $$|a_n-1|=1over n^2+2$$therefore if $n>1over sqrtepsilon$ we obtain $$n^2+2>1over epsilon+2>1over epsilon$$and $$|a_n-1|<epsilon$$ hence the result.






                  share|cite|improve this answer









                  $endgroup$















                    0












                    0








                    0





                    $begingroup$

                    $$|a_n-1|=1over n^2+2$$therefore if $n>1over sqrtepsilon$ we obtain $$n^2+2>1over epsilon+2>1over epsilon$$and $$|a_n-1|<epsilon$$ hence the result.






                    share|cite|improve this answer









                    $endgroup$



                    $$|a_n-1|=1over n^2+2$$therefore if $n>1over sqrtepsilon$ we obtain $$n^2+2>1over epsilon+2>1over epsilon$$and $$|a_n-1|<epsilon$$ hence the result.







                    share|cite|improve this answer












                    share|cite|improve this answer



                    share|cite|improve this answer










                    answered Mar 13 at 12:39









                    Mostafa AyazMostafa Ayaz

                    16.5k3939




                    16.5k3939





















                        0












                        $begingroup$

                        First of all rewrite the expression:
                        $a_n := fracn^2+1n^2+2 = 1-frac1n^2+2$.



                        Choose $N in mathbbN$ and let $n geq N$. Then we have:



                        $ Big | a_n -1 Big | = frac1n^2+2 leq frac1n^2 leq frac1N^2$



                        Do you have an idea how to choose $N in mathbbN$ from this inequality?






                        share|cite|improve this answer










                        New contributor




                        GordonFreeman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                        Check out our Code of Conduct.






                        $endgroup$

















                          0












                          $begingroup$

                          First of all rewrite the expression:
                          $a_n := fracn^2+1n^2+2 = 1-frac1n^2+2$.



                          Choose $N in mathbbN$ and let $n geq N$. Then we have:



                          $ Big | a_n -1 Big | = frac1n^2+2 leq frac1n^2 leq frac1N^2$



                          Do you have an idea how to choose $N in mathbbN$ from this inequality?






                          share|cite|improve this answer










                          New contributor




                          GordonFreeman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                          Check out our Code of Conduct.






                          $endgroup$















                            0












                            0








                            0





                            $begingroup$

                            First of all rewrite the expression:
                            $a_n := fracn^2+1n^2+2 = 1-frac1n^2+2$.



                            Choose $N in mathbbN$ and let $n geq N$. Then we have:



                            $ Big | a_n -1 Big | = frac1n^2+2 leq frac1n^2 leq frac1N^2$



                            Do you have an idea how to choose $N in mathbbN$ from this inequality?






                            share|cite|improve this answer










                            New contributor




                            GordonFreeman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                            Check out our Code of Conduct.






                            $endgroup$



                            First of all rewrite the expression:
                            $a_n := fracn^2+1n^2+2 = 1-frac1n^2+2$.



                            Choose $N in mathbbN$ and let $n geq N$. Then we have:



                            $ Big | a_n -1 Big | = frac1n^2+2 leq frac1n^2 leq frac1N^2$



                            Do you have an idea how to choose $N in mathbbN$ from this inequality?







                            share|cite|improve this answer










                            New contributor




                            GordonFreeman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                            Check out our Code of Conduct.









                            share|cite|improve this answer



                            share|cite|improve this answer








                            edited Mar 13 at 12:51





















                            New contributor




                            GordonFreeman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                            Check out our Code of Conduct.









                            answered Mar 13 at 12:24









                            GordonFreemanGordonFreeman

                            63




                            63




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                            GordonFreeman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                            Check out our Code of Conduct.




















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