$lim_{ntoinfty} n^{x}(a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=ae^x$











up vote
2
down vote

favorite












Let $ (a_{n})$ be positive sequence, $a,x in R quad $ and $ lim_{ntoinfty} n^{x}a_{n}=a$.



Prove that $lim_{ntoinfty} n^{x}(a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=ae^x$



I know that $lim_{ntoinfty} (a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=lim_{ntoinfty} a_{n}$ but don't have idea how to use it










share|cite|improve this question




























    up vote
    2
    down vote

    favorite












    Let $ (a_{n})$ be positive sequence, $a,x in R quad $ and $ lim_{ntoinfty} n^{x}a_{n}=a$.



    Prove that $lim_{ntoinfty} n^{x}(a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=ae^x$



    I know that $lim_{ntoinfty} (a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=lim_{ntoinfty} a_{n}$ but don't have idea how to use it










    share|cite|improve this question


























      up vote
      2
      down vote

      favorite









      up vote
      2
      down vote

      favorite











      Let $ (a_{n})$ be positive sequence, $a,x in R quad $ and $ lim_{ntoinfty} n^{x}a_{n}=a$.



      Prove that $lim_{ntoinfty} n^{x}(a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=ae^x$



      I know that $lim_{ntoinfty} (a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=lim_{ntoinfty} a_{n}$ but don't have idea how to use it










      share|cite|improve this question















      Let $ (a_{n})$ be positive sequence, $a,x in R quad $ and $ lim_{ntoinfty} n^{x}a_{n}=a$.



      Prove that $lim_{ntoinfty} n^{x}(a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=ae^x$



      I know that $lim_{ntoinfty} (a_{1}a_{2}ldots a_{n})^{frac{1}{n}}=lim_{ntoinfty} a_{n}$ but don't have idea how to use it







      limits






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited yesterday









      gimusi

      86k74292




      86k74292










      asked yesterday









      math.trouble

      455




      455






















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          3
          down vote



          accepted










          HINT



          By ratio root criteria we have



          $$frac{(n+1)^{x(n+1)}a_{1}a_{2}ldots a_{n+1}}{n^{xn}a_{1}a_{2}ldots a_{n}}=(n+1)^xa_{n+1}left(1+frac1nright)^{nx}$$






          share|cite|improve this answer





















            Your Answer





            StackExchange.ifUsing("editor", function () {
            return StackExchange.using("mathjaxEditing", function () {
            StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
            StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
            });
            });
            }, "mathjax-editing");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "69"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            noCode: true, onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














             

            draft saved


            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3006994%2flim-n-to-infty-nxa-1a-2-ldots-a-n-frac1n-aex%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            3
            down vote



            accepted










            HINT



            By ratio root criteria we have



            $$frac{(n+1)^{x(n+1)}a_{1}a_{2}ldots a_{n+1}}{n^{xn}a_{1}a_{2}ldots a_{n}}=(n+1)^xa_{n+1}left(1+frac1nright)^{nx}$$






            share|cite|improve this answer

























              up vote
              3
              down vote



              accepted










              HINT



              By ratio root criteria we have



              $$frac{(n+1)^{x(n+1)}a_{1}a_{2}ldots a_{n+1}}{n^{xn}a_{1}a_{2}ldots a_{n}}=(n+1)^xa_{n+1}left(1+frac1nright)^{nx}$$






              share|cite|improve this answer























                up vote
                3
                down vote



                accepted







                up vote
                3
                down vote



                accepted






                HINT



                By ratio root criteria we have



                $$frac{(n+1)^{x(n+1)}a_{1}a_{2}ldots a_{n+1}}{n^{xn}a_{1}a_{2}ldots a_{n}}=(n+1)^xa_{n+1}left(1+frac1nright)^{nx}$$






                share|cite|improve this answer












                HINT



                By ratio root criteria we have



                $$frac{(n+1)^{x(n+1)}a_{1}a_{2}ldots a_{n+1}}{n^{xn}a_{1}a_{2}ldots a_{n}}=(n+1)^xa_{n+1}left(1+frac1nright)^{nx}$$







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered yesterday









                gimusi

                86k74292




                86k74292






























                     

                    draft saved


                    draft discarded



















































                     


                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3006994%2flim-n-to-infty-nxa-1a-2-ldots-a-n-frac1n-aex%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    Berounka

                    Sphinx de Gizeh

                    Different font size/position of beamer's navigation symbols template's content depending on regular/plain...