Evaluate $int{frac{e^{2x}} {sqrt{1-e^x}}} dx$











up vote
3
down vote

favorite












Evaluate $$displaystyleint{frac{e^{2x}} {sqrt{1-e^x}}} dx.$$



I tried to solve by using integration by parts, but I couldn't find a solution. What method should I use to integrate this?










share|cite|improve this question
























  • Welcome to Stack Exchange. Can you tell us what you tried to do to solve this problem?
    – Asimov
    May 19 '14 at 1:39






  • 1




    Is that supposed to be $e^{2x}$ or $e^2x$, as this drastically changes the difficulty of the integral
    – Triatticus
    May 19 '14 at 1:45

















up vote
3
down vote

favorite












Evaluate $$displaystyleint{frac{e^{2x}} {sqrt{1-e^x}}} dx.$$



I tried to solve by using integration by parts, but I couldn't find a solution. What method should I use to integrate this?










share|cite|improve this question
























  • Welcome to Stack Exchange. Can you tell us what you tried to do to solve this problem?
    – Asimov
    May 19 '14 at 1:39






  • 1




    Is that supposed to be $e^{2x}$ or $e^2x$, as this drastically changes the difficulty of the integral
    – Triatticus
    May 19 '14 at 1:45















up vote
3
down vote

favorite









up vote
3
down vote

favorite











Evaluate $$displaystyleint{frac{e^{2x}} {sqrt{1-e^x}}} dx.$$



I tried to solve by using integration by parts, but I couldn't find a solution. What method should I use to integrate this?










share|cite|improve this question















Evaluate $$displaystyleint{frac{e^{2x}} {sqrt{1-e^x}}} dx.$$



I tried to solve by using integration by parts, but I couldn't find a solution. What method should I use to integrate this?







integration indefinite-integrals






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 24 at 6:17









Martin Sleziak

44.5k7115268




44.5k7115268










asked May 19 '14 at 1:24









user151911

162




162












  • Welcome to Stack Exchange. Can you tell us what you tried to do to solve this problem?
    – Asimov
    May 19 '14 at 1:39






  • 1




    Is that supposed to be $e^{2x}$ or $e^2x$, as this drastically changes the difficulty of the integral
    – Triatticus
    May 19 '14 at 1:45




















  • Welcome to Stack Exchange. Can you tell us what you tried to do to solve this problem?
    – Asimov
    May 19 '14 at 1:39






  • 1




    Is that supposed to be $e^{2x}$ or $e^2x$, as this drastically changes the difficulty of the integral
    – Triatticus
    May 19 '14 at 1:45


















Welcome to Stack Exchange. Can you tell us what you tried to do to solve this problem?
– Asimov
May 19 '14 at 1:39




Welcome to Stack Exchange. Can you tell us what you tried to do to solve this problem?
– Asimov
May 19 '14 at 1:39




1




1




Is that supposed to be $e^{2x}$ or $e^2x$, as this drastically changes the difficulty of the integral
– Triatticus
May 19 '14 at 1:45






Is that supposed to be $e^{2x}$ or $e^2x$, as this drastically changes the difficulty of the integral
– Triatticus
May 19 '14 at 1:45












3 Answers
3






active

oldest

votes

















up vote
6
down vote













Hint: Let $u=1-e^{x}$${}{}{}{}{}{}{}$






share|cite|improve this answer





















  • by substitution ? But this integral its in the "integral by parts list", sorry bad english I tried u = (1-e^x)^-1/2
    – user151911
    May 19 '14 at 1:43






  • 1




    An alternative way to solve this using integration by parts is to notice that $frac{e^{2x}}{sqrt{1-e^{x}}}=frac{e^{x}}{sqrt{1-e^{x}}}e^{x}=bigg(frac{d}{dx}(2 sqrt{1-e^{x}})bigg)e^{x}$
    – user71352
    May 19 '14 at 1:46




















up vote
0
down vote













$$
intfrac{e^x}{sqrt{1-e^x}}underbrace{Big(e^x , dxBig)}_{text{HINT}}
$$



After that substitution (the one that is hinted at), use another substitution, namely a rationalizing substitution.






share|cite|improve this answer




























    up vote
    0
    down vote













    $$I=intfrac{e^{2x}}{(1-e^x)^{1/2}}dx$$
    $$I=intfrac{e^x}{(1-e^x)^{1/2}}e^xdx$$
    Substitution: $u^2=1-e^xRightarrow -2udu=e^xdx$.
    $$I=intfrac{1-u^2}{(u^2)^{1/2}}(-2)udu$$
    $$I=-2int(1-u^2)du$$
    $$I=2int(u^2-1)du$$
    $$I=2int u^2du-2int du$$
    $$I=frac{2u^4}{4}-2u$$
    $$I=frac{(1-e^x)^2}{2}-2sqrt{1-e^x}+C$$






    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%2f801006%2fevaluate-int-frace2x-sqrt1-ex-dx%23new-answer', 'question_page');
      }
      );

      Post as a guest















      Required, but never shown

























      3 Answers
      3






      active

      oldest

      votes








      3 Answers
      3






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes








      up vote
      6
      down vote













      Hint: Let $u=1-e^{x}$${}{}{}{}{}{}{}$






      share|cite|improve this answer





















      • by substitution ? But this integral its in the "integral by parts list", sorry bad english I tried u = (1-e^x)^-1/2
        – user151911
        May 19 '14 at 1:43






      • 1




        An alternative way to solve this using integration by parts is to notice that $frac{e^{2x}}{sqrt{1-e^{x}}}=frac{e^{x}}{sqrt{1-e^{x}}}e^{x}=bigg(frac{d}{dx}(2 sqrt{1-e^{x}})bigg)e^{x}$
        – user71352
        May 19 '14 at 1:46

















      up vote
      6
      down vote













      Hint: Let $u=1-e^{x}$${}{}{}{}{}{}{}$






      share|cite|improve this answer





















      • by substitution ? But this integral its in the "integral by parts list", sorry bad english I tried u = (1-e^x)^-1/2
        – user151911
        May 19 '14 at 1:43






      • 1




        An alternative way to solve this using integration by parts is to notice that $frac{e^{2x}}{sqrt{1-e^{x}}}=frac{e^{x}}{sqrt{1-e^{x}}}e^{x}=bigg(frac{d}{dx}(2 sqrt{1-e^{x}})bigg)e^{x}$
        – user71352
        May 19 '14 at 1:46















      up vote
      6
      down vote










      up vote
      6
      down vote









      Hint: Let $u=1-e^{x}$${}{}{}{}{}{}{}$






      share|cite|improve this answer












      Hint: Let $u=1-e^{x}$${}{}{}{}{}{}{}$







      share|cite|improve this answer












      share|cite|improve this answer



      share|cite|improve this answer










      answered May 19 '14 at 1:38









      user71352

      11.3k21025




      11.3k21025












      • by substitution ? But this integral its in the "integral by parts list", sorry bad english I tried u = (1-e^x)^-1/2
        – user151911
        May 19 '14 at 1:43






      • 1




        An alternative way to solve this using integration by parts is to notice that $frac{e^{2x}}{sqrt{1-e^{x}}}=frac{e^{x}}{sqrt{1-e^{x}}}e^{x}=bigg(frac{d}{dx}(2 sqrt{1-e^{x}})bigg)e^{x}$
        – user71352
        May 19 '14 at 1:46




















      • by substitution ? But this integral its in the "integral by parts list", sorry bad english I tried u = (1-e^x)^-1/2
        – user151911
        May 19 '14 at 1:43






      • 1




        An alternative way to solve this using integration by parts is to notice that $frac{e^{2x}}{sqrt{1-e^{x}}}=frac{e^{x}}{sqrt{1-e^{x}}}e^{x}=bigg(frac{d}{dx}(2 sqrt{1-e^{x}})bigg)e^{x}$
        – user71352
        May 19 '14 at 1:46


















      by substitution ? But this integral its in the "integral by parts list", sorry bad english I tried u = (1-e^x)^-1/2
      – user151911
      May 19 '14 at 1:43




      by substitution ? But this integral its in the "integral by parts list", sorry bad english I tried u = (1-e^x)^-1/2
      – user151911
      May 19 '14 at 1:43




      1




      1




      An alternative way to solve this using integration by parts is to notice that $frac{e^{2x}}{sqrt{1-e^{x}}}=frac{e^{x}}{sqrt{1-e^{x}}}e^{x}=bigg(frac{d}{dx}(2 sqrt{1-e^{x}})bigg)e^{x}$
      – user71352
      May 19 '14 at 1:46






      An alternative way to solve this using integration by parts is to notice that $frac{e^{2x}}{sqrt{1-e^{x}}}=frac{e^{x}}{sqrt{1-e^{x}}}e^{x}=bigg(frac{d}{dx}(2 sqrt{1-e^{x}})bigg)e^{x}$
      – user71352
      May 19 '14 at 1:46












      up vote
      0
      down vote













      $$
      intfrac{e^x}{sqrt{1-e^x}}underbrace{Big(e^x , dxBig)}_{text{HINT}}
      $$



      After that substitution (the one that is hinted at), use another substitution, namely a rationalizing substitution.






      share|cite|improve this answer

























        up vote
        0
        down vote













        $$
        intfrac{e^x}{sqrt{1-e^x}}underbrace{Big(e^x , dxBig)}_{text{HINT}}
        $$



        After that substitution (the one that is hinted at), use another substitution, namely a rationalizing substitution.






        share|cite|improve this answer























          up vote
          0
          down vote










          up vote
          0
          down vote









          $$
          intfrac{e^x}{sqrt{1-e^x}}underbrace{Big(e^x , dxBig)}_{text{HINT}}
          $$



          After that substitution (the one that is hinted at), use another substitution, namely a rationalizing substitution.






          share|cite|improve this answer












          $$
          intfrac{e^x}{sqrt{1-e^x}}underbrace{Big(e^x , dxBig)}_{text{HINT}}
          $$



          After that substitution (the one that is hinted at), use another substitution, namely a rationalizing substitution.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered May 19 '14 at 2:52









          Michael Hardy

          1




          1






















              up vote
              0
              down vote













              $$I=intfrac{e^{2x}}{(1-e^x)^{1/2}}dx$$
              $$I=intfrac{e^x}{(1-e^x)^{1/2}}e^xdx$$
              Substitution: $u^2=1-e^xRightarrow -2udu=e^xdx$.
              $$I=intfrac{1-u^2}{(u^2)^{1/2}}(-2)udu$$
              $$I=-2int(1-u^2)du$$
              $$I=2int(u^2-1)du$$
              $$I=2int u^2du-2int du$$
              $$I=frac{2u^4}{4}-2u$$
              $$I=frac{(1-e^x)^2}{2}-2sqrt{1-e^x}+C$$






              share|cite|improve this answer

























                up vote
                0
                down vote













                $$I=intfrac{e^{2x}}{(1-e^x)^{1/2}}dx$$
                $$I=intfrac{e^x}{(1-e^x)^{1/2}}e^xdx$$
                Substitution: $u^2=1-e^xRightarrow -2udu=e^xdx$.
                $$I=intfrac{1-u^2}{(u^2)^{1/2}}(-2)udu$$
                $$I=-2int(1-u^2)du$$
                $$I=2int(u^2-1)du$$
                $$I=2int u^2du-2int du$$
                $$I=frac{2u^4}{4}-2u$$
                $$I=frac{(1-e^x)^2}{2}-2sqrt{1-e^x}+C$$






                share|cite|improve this answer























                  up vote
                  0
                  down vote










                  up vote
                  0
                  down vote









                  $$I=intfrac{e^{2x}}{(1-e^x)^{1/2}}dx$$
                  $$I=intfrac{e^x}{(1-e^x)^{1/2}}e^xdx$$
                  Substitution: $u^2=1-e^xRightarrow -2udu=e^xdx$.
                  $$I=intfrac{1-u^2}{(u^2)^{1/2}}(-2)udu$$
                  $$I=-2int(1-u^2)du$$
                  $$I=2int(u^2-1)du$$
                  $$I=2int u^2du-2int du$$
                  $$I=frac{2u^4}{4}-2u$$
                  $$I=frac{(1-e^x)^2}{2}-2sqrt{1-e^x}+C$$






                  share|cite|improve this answer












                  $$I=intfrac{e^{2x}}{(1-e^x)^{1/2}}dx$$
                  $$I=intfrac{e^x}{(1-e^x)^{1/2}}e^xdx$$
                  Substitution: $u^2=1-e^xRightarrow -2udu=e^xdx$.
                  $$I=intfrac{1-u^2}{(u^2)^{1/2}}(-2)udu$$
                  $$I=-2int(1-u^2)du$$
                  $$I=2int(u^2-1)du$$
                  $$I=2int u^2du-2int du$$
                  $$I=frac{2u^4}{4}-2u$$
                  $$I=frac{(1-e^x)^2}{2}-2sqrt{1-e^x}+C$$







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Nov 11 at 21:22









                  clathratus

                  2,141221




                  2,141221






























                      draft saved

                      draft discarded




















































                      Thanks for contributing an answer to Mathematics Stack Exchange!


                      • Please be sure to answer the question. Provide details and share your research!

                      But avoid



                      • Asking for help, clarification, or responding to other answers.

                      • Making statements based on opinion; back them up with references or personal experience.


                      Use MathJax to format equations. MathJax reference.


                      To learn more, see our tips on writing great answers.





                      Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                      Please pay close attention to the following guidance:


                      • Please be sure to answer the question. Provide details and share your research!

                      But avoid



                      • Asking for help, clarification, or responding to other answers.

                      • Making statements based on opinion; back them up with references or personal experience.


                      To learn more, see our tips on writing great answers.




                      draft saved


                      draft discarded














                      StackExchange.ready(
                      function () {
                      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f801006%2fevaluate-int-frace2x-sqrt1-ex-dx%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...