Finding discrete solutions to inequality involving Exponential Integral












1












$begingroup$


I want to identify the least natural number $n$ (of course, it suffices to solve this problem for the reals, and then take the floor) such that



$$-c text{Ei}left(-e^{frac{a-d}{c}} (n+1)right)+a-b (n+1)+c log (n+1)+gamma c < 0,$$



where $text{Ei}$ is the exponential integral, $a,b, c, d$ are arbitrary real constants, and $gamma$ is the Euler-Mascheroni constant.



I have tried moving the terms around etc., to no avail; Mathematica also does not seem able to solve this.



I was wondering if there are any easy ways to solve this, or at least simplify it?










share|cite|improve this question









$endgroup$

















    1












    $begingroup$


    I want to identify the least natural number $n$ (of course, it suffices to solve this problem for the reals, and then take the floor) such that



    $$-c text{Ei}left(-e^{frac{a-d}{c}} (n+1)right)+a-b (n+1)+c log (n+1)+gamma c < 0,$$



    where $text{Ei}$ is the exponential integral, $a,b, c, d$ are arbitrary real constants, and $gamma$ is the Euler-Mascheroni constant.



    I have tried moving the terms around etc., to no avail; Mathematica also does not seem able to solve this.



    I was wondering if there are any easy ways to solve this, or at least simplify it?










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      I want to identify the least natural number $n$ (of course, it suffices to solve this problem for the reals, and then take the floor) such that



      $$-c text{Ei}left(-e^{frac{a-d}{c}} (n+1)right)+a-b (n+1)+c log (n+1)+gamma c < 0,$$



      where $text{Ei}$ is the exponential integral, $a,b, c, d$ are arbitrary real constants, and $gamma$ is the Euler-Mascheroni constant.



      I have tried moving the terms around etc., to no avail; Mathematica also does not seem able to solve this.



      I was wondering if there are any easy ways to solve this, or at least simplify it?










      share|cite|improve this question









      $endgroup$




      I want to identify the least natural number $n$ (of course, it suffices to solve this problem for the reals, and then take the floor) such that



      $$-c text{Ei}left(-e^{frac{a-d}{c}} (n+1)right)+a-b (n+1)+c log (n+1)+gamma c < 0,$$



      where $text{Ei}$ is the exponential integral, $a,b, c, d$ are arbitrary real constants, and $gamma$ is the Euler-Mascheroni constant.



      I have tried moving the terms around etc., to no avail; Mathematica also does not seem able to solve this.



      I was wondering if there are any easy ways to solve this, or at least simplify it?







      inequality optimization integral-inequality discrete-optimization functional-inequalities






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Jan 1 at 16:45









      jackson5jackson5

      618513




      618513






















          0






          active

          oldest

          votes











          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',
          autoActivateHeartbeat: false,
          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%2f3058643%2ffinding-discrete-solutions-to-inequality-involving-exponential-integral%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















          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.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3058643%2ffinding-discrete-solutions-to-inequality-involving-exponential-integral%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

          Quarter-circle Tiles

          build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

          Mont Emei