Prove: $ b_n underset{ntoinfty}{longrightarrow} L, text{as} b_n = frac{sum_{k=1}^{n}t_{k}cdot...











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Given $(a_{n})_{n=1}^infty$ , a sequence that converges to $L$ ($L$ is not necessarily $in mathbb{R}$).



Let $left(t_{n}right)$ be a positive sequence such that:



$$ sum_{k=1}^{n}t_{k} underset{ntoinfty}{longrightarrow} infty$$



We'll define:



$$ b_n = frac{sum_{k=1}^{n}t_{k}cdot {a_k}}{sum_{k=1}^{n}t_{k}} $$



Prove: $ b_n underset{ntoinfty}{longrightarrow} L$.










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    up vote
    0
    down vote

    favorite












    Given $(a_{n})_{n=1}^infty$ , a sequence that converges to $L$ ($L$ is not necessarily $in mathbb{R}$).



    Let $left(t_{n}right)$ be a positive sequence such that:



    $$ sum_{k=1}^{n}t_{k} underset{ntoinfty}{longrightarrow} infty$$



    We'll define:



    $$ b_n = frac{sum_{k=1}^{n}t_{k}cdot {a_k}}{sum_{k=1}^{n}t_{k}} $$



    Prove: $ b_n underset{ntoinfty}{longrightarrow} L$.










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      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      Given $(a_{n})_{n=1}^infty$ , a sequence that converges to $L$ ($L$ is not necessarily $in mathbb{R}$).



      Let $left(t_{n}right)$ be a positive sequence such that:



      $$ sum_{k=1}^{n}t_{k} underset{ntoinfty}{longrightarrow} infty$$



      We'll define:



      $$ b_n = frac{sum_{k=1}^{n}t_{k}cdot {a_k}}{sum_{k=1}^{n}t_{k}} $$



      Prove: $ b_n underset{ntoinfty}{longrightarrow} L$.










      share|cite|improve this question















      Given $(a_{n})_{n=1}^infty$ , a sequence that converges to $L$ ($L$ is not necessarily $in mathbb{R}$).



      Let $left(t_{n}right)$ be a positive sequence such that:



      $$ sum_{k=1}^{n}t_{k} underset{ntoinfty}{longrightarrow} infty$$



      We'll define:



      $$ b_n = frac{sum_{k=1}^{n}t_{k}cdot {a_k}}{sum_{k=1}^{n}t_{k}} $$



      Prove: $ b_n underset{ntoinfty}{longrightarrow} L$.







      calculus sequences-and-series






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      edited Nov 16 at 12:12

























      asked Nov 15 at 13:06









      Jneven

      680320




      680320






















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          It is an easy consquence of Theorem of Stolz : https://en.wikipedia.org/wiki/Stolz%E2%80%93Ces%C3%A0ro_theorem






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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










            It is an easy consquence of Theorem of Stolz : https://en.wikipedia.org/wiki/Stolz%E2%80%93Ces%C3%A0ro_theorem






            share|cite|improve this answer

























              up vote
              2
              down vote



              accepted










              It is an easy consquence of Theorem of Stolz : https://en.wikipedia.org/wiki/Stolz%E2%80%93Ces%C3%A0ro_theorem






              share|cite|improve this answer























                up vote
                2
                down vote



                accepted







                up vote
                2
                down vote



                accepted






                It is an easy consquence of Theorem of Stolz : https://en.wikipedia.org/wiki/Stolz%E2%80%93Ces%C3%A0ro_theorem






                share|cite|improve this answer












                It is an easy consquence of Theorem of Stolz : https://en.wikipedia.org/wiki/Stolz%E2%80%93Ces%C3%A0ro_theorem







                share|cite|improve this answer












                share|cite|improve this answer



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                answered Nov 16 at 12:09









                MotylaNogaTomkaMazura

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