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






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      asked May 6 '17 at 10:10









      Three OneFourThree OneFour

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      1099






















          2 Answers
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          $begingroup$

          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









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              2 Answers
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              2 Answers
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              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

                  74.4k42865




                  74.4k42865























                      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






























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