Sequence limit with form $infty cdot 0$ [closed]












1














Compute $lim_{ntoinfty} 2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}$.



I tried to reduce this to $e$ raised to some power, but I didn't succeed.










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closed as off-topic by amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser Nov 27 at 4:14


This question appears to be off-topic. The users who voted to close gave this specific reason:


  • "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser

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    1














    Compute $lim_{ntoinfty} 2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}$.



    I tried to reduce this to $e$ raised to some power, but I didn't succeed.










    share|cite|improve this question















    closed as off-topic by amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser Nov 27 at 4:14


    This question appears to be off-topic. The users who voted to close gave this specific reason:


    • "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser

    If this question can be reworded to fit the rules in the help center, please edit the question.
















      1












      1








      1







      Compute $lim_{ntoinfty} 2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}$.



      I tried to reduce this to $e$ raised to some power, but I didn't succeed.










      share|cite|improve this question















      Compute $lim_{ntoinfty} 2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}$.



      I tried to reduce this to $e$ raised to some power, but I didn't succeed.







      calculus algebra-precalculus limits






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      edited Nov 26 at 16:56









      Servaes

      22.3k33793




      22.3k33793










      asked Nov 26 at 16:50









      user69503

      626




      626




      closed as off-topic by amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser Nov 27 at 4:14


      This question appears to be off-topic. The users who voted to close gave this specific reason:


      • "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser

      If this question can be reworded to fit the rules in the help center, please edit the question.




      closed as off-topic by amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser Nov 27 at 4:14


      This question appears to be off-topic. The users who voted to close gave this specific reason:


      • "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – amWhy, Shailesh, Cesareo, Jyrki Lahtonen, KReiser

      If this question can be reworded to fit the rules in the help center, please edit the question.






















          2 Answers
          2






          active

          oldest

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          5














          HINT: Note that for all $ngeq0$ we have
          $$2^n cdotleft(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=frac{1}{2}left(frac{4n^2+8n+2}{4n^2+12n+8}right)^{n+1}.$$






          share|cite|improve this answer





















          • Very good hint at the key point!
            – gimusi
            Nov 26 at 17:19



















          1














          HINT



          We have that



          $$2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=$$$$=frac12 cdot left(frac{4n^2+8n+4}{4n^2+12n+8}right)^{n+1}=frac12 cdot left(frac{4n^2+12n+8-4n-4}{4n^2+12n+8}right)^{n+1}=$$



          $$=frac12 cdot left[left(1-frac{4n+4}{4n^2+12n+8}right)^{frac{4n^2+12n+8}{4n+4}}right]^{frac{(4n+4)(n+1)}{4n^2+12n+8}}$$






          share|cite|improve this answer























          • The first linebreak is in a rather unfortunate place. The last expression terrifies me.
            – Servaes
            Nov 26 at 17:17












          • @Servaes Yes you are right! I fix that
            – gimusi
            Nov 26 at 17:18










          • @Servaes That's only apparently terrifiant :)
            – gimusi
            Nov 26 at 17:24


















          2 Answers
          2






          active

          oldest

          votes








          2 Answers
          2






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          5














          HINT: Note that for all $ngeq0$ we have
          $$2^n cdotleft(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=frac{1}{2}left(frac{4n^2+8n+2}{4n^2+12n+8}right)^{n+1}.$$






          share|cite|improve this answer





















          • Very good hint at the key point!
            – gimusi
            Nov 26 at 17:19
















          5














          HINT: Note that for all $ngeq0$ we have
          $$2^n cdotleft(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=frac{1}{2}left(frac{4n^2+8n+2}{4n^2+12n+8}right)^{n+1}.$$






          share|cite|improve this answer





















          • Very good hint at the key point!
            – gimusi
            Nov 26 at 17:19














          5












          5








          5






          HINT: Note that for all $ngeq0$ we have
          $$2^n cdotleft(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=frac{1}{2}left(frac{4n^2+8n+2}{4n^2+12n+8}right)^{n+1}.$$






          share|cite|improve this answer












          HINT: Note that for all $ngeq0$ we have
          $$2^n cdotleft(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=frac{1}{2}left(frac{4n^2+8n+2}{4n^2+12n+8}right)^{n+1}.$$







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Nov 26 at 16:52









          Servaes

          22.3k33793




          22.3k33793












          • Very good hint at the key point!
            – gimusi
            Nov 26 at 17:19


















          • Very good hint at the key point!
            – gimusi
            Nov 26 at 17:19
















          Very good hint at the key point!
          – gimusi
          Nov 26 at 17:19




          Very good hint at the key point!
          – gimusi
          Nov 26 at 17:19











          1














          HINT



          We have that



          $$2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=$$$$=frac12 cdot left(frac{4n^2+8n+4}{4n^2+12n+8}right)^{n+1}=frac12 cdot left(frac{4n^2+12n+8-4n-4}{4n^2+12n+8}right)^{n+1}=$$



          $$=frac12 cdot left[left(1-frac{4n+4}{4n^2+12n+8}right)^{frac{4n^2+12n+8}{4n+4}}right]^{frac{(4n+4)(n+1)}{4n^2+12n+8}}$$






          share|cite|improve this answer























          • The first linebreak is in a rather unfortunate place. The last expression terrifies me.
            – Servaes
            Nov 26 at 17:17












          • @Servaes Yes you are right! I fix that
            – gimusi
            Nov 26 at 17:18










          • @Servaes That's only apparently terrifiant :)
            – gimusi
            Nov 26 at 17:24
















          1














          HINT



          We have that



          $$2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=$$$$=frac12 cdot left(frac{4n^2+8n+4}{4n^2+12n+8}right)^{n+1}=frac12 cdot left(frac{4n^2+12n+8-4n-4}{4n^2+12n+8}right)^{n+1}=$$



          $$=frac12 cdot left[left(1-frac{4n+4}{4n^2+12n+8}right)^{frac{4n^2+12n+8}{4n+4}}right]^{frac{(4n+4)(n+1)}{4n^2+12n+8}}$$






          share|cite|improve this answer























          • The first linebreak is in a rather unfortunate place. The last expression terrifies me.
            – Servaes
            Nov 26 at 17:17












          • @Servaes Yes you are right! I fix that
            – gimusi
            Nov 26 at 17:18










          • @Servaes That's only apparently terrifiant :)
            – gimusi
            Nov 26 at 17:24














          1












          1








          1






          HINT



          We have that



          $$2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=$$$$=frac12 cdot left(frac{4n^2+8n+4}{4n^2+12n+8}right)^{n+1}=frac12 cdot left(frac{4n^2+12n+8-4n-4}{4n^2+12n+8}right)^{n+1}=$$



          $$=frac12 cdot left[left(1-frac{4n+4}{4n^2+12n+8}right)^{frac{4n^2+12n+8}{4n+4}}right]^{frac{(4n+4)(n+1)}{4n^2+12n+8}}$$






          share|cite|improve this answer














          HINT



          We have that



          $$2^n cdot left(frac{2n^2+4n+1}{4n^2+12n+8}right)^{n+1}=$$$$=frac12 cdot left(frac{4n^2+8n+4}{4n^2+12n+8}right)^{n+1}=frac12 cdot left(frac{4n^2+12n+8-4n-4}{4n^2+12n+8}right)^{n+1}=$$



          $$=frac12 cdot left[left(1-frac{4n+4}{4n^2+12n+8}right)^{frac{4n^2+12n+8}{4n+4}}right]^{frac{(4n+4)(n+1)}{4n^2+12n+8}}$$







          share|cite|improve this answer














          share|cite|improve this answer



          share|cite|improve this answer








          edited Nov 26 at 17:18

























          answered Nov 26 at 17:10









          gimusi

          1




          1












          • The first linebreak is in a rather unfortunate place. The last expression terrifies me.
            – Servaes
            Nov 26 at 17:17












          • @Servaes Yes you are right! I fix that
            – gimusi
            Nov 26 at 17:18










          • @Servaes That's only apparently terrifiant :)
            – gimusi
            Nov 26 at 17:24


















          • The first linebreak is in a rather unfortunate place. The last expression terrifies me.
            – Servaes
            Nov 26 at 17:17












          • @Servaes Yes you are right! I fix that
            – gimusi
            Nov 26 at 17:18










          • @Servaes That's only apparently terrifiant :)
            – gimusi
            Nov 26 at 17:24
















          The first linebreak is in a rather unfortunate place. The last expression terrifies me.
          – Servaes
          Nov 26 at 17:17






          The first linebreak is in a rather unfortunate place. The last expression terrifies me.
          – Servaes
          Nov 26 at 17:17














          @Servaes Yes you are right! I fix that
          – gimusi
          Nov 26 at 17:18




          @Servaes Yes you are right! I fix that
          – gimusi
          Nov 26 at 17:18












          @Servaes That's only apparently terrifiant :)
          – gimusi
          Nov 26 at 17:24




          @Servaes That's only apparently terrifiant :)
          – gimusi
          Nov 26 at 17:24



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