How to find the intersect point between two sine waves?












1












$begingroup$


I'm trying to find the points where (y = 2 sin x) and (x = 2 sin y) intersect, besides (0, 0).
I've managed to work out that 2 sin x should equal x.



My classpad can give me an answer that I believe is right, simply by looking at these two sine functions on a graph. But how can I go about solving this problem?



Thanks in advance.










share|cite|improve this question









$endgroup$

















    1












    $begingroup$


    I'm trying to find the points where (y = 2 sin x) and (x = 2 sin y) intersect, besides (0, 0).
    I've managed to work out that 2 sin x should equal x.



    My classpad can give me an answer that I believe is right, simply by looking at these two sine functions on a graph. But how can I go about solving this problem?



    Thanks in advance.










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      I'm trying to find the points where (y = 2 sin x) and (x = 2 sin y) intersect, besides (0, 0).
      I've managed to work out that 2 sin x should equal x.



      My classpad can give me an answer that I believe is right, simply by looking at these two sine functions on a graph. But how can I go about solving this problem?



      Thanks in advance.










      share|cite|improve this question









      $endgroup$




      I'm trying to find the points where (y = 2 sin x) and (x = 2 sin y) intersect, besides (0, 0).
      I've managed to work out that 2 sin x should equal x.



      My classpad can give me an answer that I believe is right, simply by looking at these two sine functions on a graph. But how can I go about solving this problem?



      Thanks in advance.







      trigonometry






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked May 6 '17 at 10:10









      Three OneFourThree OneFour

      1099




      1099






















          2 Answers
          2






          active

          oldest

          votes


















          0












          $begingroup$

          plugging $$x=2sin(y)$$ into your first equation you will get
          $$y=2sin(2sin(y))$$ this equation can only be solved by a numerical way,e.g. the Newton-Raphson method. one solution is given by $$1.895494267$$






          share|cite|improve this answer









          $endgroup$





















            0












            $begingroup$

            You can find the numerical value of the intersection with a common scientific calculator repeatedly calculating "sin" (take care that trigonometric functions are set to "rad") and multiplying the result by $2$ until the result stabilizes (at each iteration you get the same value). You can choose any starting point between $0$ and $pi$ (but staying close to $1.9$ will make the process shorter). You are in fact looking for the attractor point of the iterated function $y=2sin x$.






            share|cite|improve this answer









            $endgroup$













              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%2f2268316%2fhow-to-find-the-intersect-point-between-two-sine-waves%23new-answer', 'question_page');
              }
              );

              Post as a guest















              Required, but never shown

























              2 Answers
              2






              active

              oldest

              votes








              2 Answers
              2






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes









              0












              $begingroup$

              plugging $$x=2sin(y)$$ into your first equation you will get
              $$y=2sin(2sin(y))$$ this equation can only be solved by a numerical way,e.g. the Newton-Raphson method. one solution is given by $$1.895494267$$






              share|cite|improve this answer









              $endgroup$


















                0












                $begingroup$

                plugging $$x=2sin(y)$$ into your first equation you will get
                $$y=2sin(2sin(y))$$ this equation can only be solved by a numerical way,e.g. the Newton-Raphson method. one solution is given by $$1.895494267$$






                share|cite|improve this answer









                $endgroup$
















                  0












                  0








                  0





                  $begingroup$

                  plugging $$x=2sin(y)$$ into your first equation you will get
                  $$y=2sin(2sin(y))$$ this equation can only be solved by a numerical way,e.g. the Newton-Raphson method. one solution is given by $$1.895494267$$






                  share|cite|improve this answer









                  $endgroup$



                  plugging $$x=2sin(y)$$ into your first equation you will get
                  $$y=2sin(2sin(y))$$ this equation can only be solved by a numerical way,e.g. the Newton-Raphson method. one solution is given by $$1.895494267$$







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered May 6 '17 at 10:16









                  Dr. Sonnhard GraubnerDr. Sonnhard Graubner

                  73.7k42864




                  73.7k42864























                      0












                      $begingroup$

                      You can find the numerical value of the intersection with a common scientific calculator repeatedly calculating "sin" (take care that trigonometric functions are set to "rad") and multiplying the result by $2$ until the result stabilizes (at each iteration you get the same value). You can choose any starting point between $0$ and $pi$ (but staying close to $1.9$ will make the process shorter). You are in fact looking for the attractor point of the iterated function $y=2sin x$.






                      share|cite|improve this answer









                      $endgroup$


















                        0












                        $begingroup$

                        You can find the numerical value of the intersection with a common scientific calculator repeatedly calculating "sin" (take care that trigonometric functions are set to "rad") and multiplying the result by $2$ until the result stabilizes (at each iteration you get the same value). You can choose any starting point between $0$ and $pi$ (but staying close to $1.9$ will make the process shorter). You are in fact looking for the attractor point of the iterated function $y=2sin x$.






                        share|cite|improve this answer









                        $endgroup$
















                          0












                          0








                          0





                          $begingroup$

                          You can find the numerical value of the intersection with a common scientific calculator repeatedly calculating "sin" (take care that trigonometric functions are set to "rad") and multiplying the result by $2$ until the result stabilizes (at each iteration you get the same value). You can choose any starting point between $0$ and $pi$ (but staying close to $1.9$ will make the process shorter). You are in fact looking for the attractor point of the iterated function $y=2sin x$.






                          share|cite|improve this answer









                          $endgroup$



                          You can find the numerical value of the intersection with a common scientific calculator repeatedly calculating "sin" (take care that trigonometric functions are set to "rad") and multiplying the result by $2$ until the result stabilizes (at each iteration you get the same value). You can choose any starting point between $0$ and $pi$ (but staying close to $1.9$ will make the process shorter). You are in fact looking for the attractor point of the iterated function $y=2sin x$.







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered May 6 '17 at 13:02









                          lesath82lesath82

                          1,921226




                          1,921226






























                              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%2f2268316%2fhow-to-find-the-intersect-point-between-two-sine-waves%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

                              Wiesbaden

                              Marschland

                              Dieringhausen