Proving $f(x,y)=left ( frac{1}{4}sin(x+y),1+frac{2}{3}arctan(x-y) right )$ is a contraction












0












$begingroup$


$f(x,y)=left ( frac{1}{4}sin(x+y),1+frac{2}{3}arctan(x-y) right )$



Prove that $f$ is a contraction



$mathbb{R}^2$ is equipped with $d((x,y),(x',y'))=|x-x'|+|y-y'|$



My problem is that I'm not able to find an upper bound of $|sin(x+y)-sin(x'+y')|$










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    $f(x,y)=left ( frac{1}{4}sin(x+y),1+frac{2}{3}arctan(x-y) right )$



    Prove that $f$ is a contraction



    $mathbb{R}^2$ is equipped with $d((x,y),(x',y'))=|x-x'|+|y-y'|$



    My problem is that I'm not able to find an upper bound of $|sin(x+y)-sin(x'+y')|$










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      $f(x,y)=left ( frac{1}{4}sin(x+y),1+frac{2}{3}arctan(x-y) right )$



      Prove that $f$ is a contraction



      $mathbb{R}^2$ is equipped with $d((x,y),(x',y'))=|x-x'|+|y-y'|$



      My problem is that I'm not able to find an upper bound of $|sin(x+y)-sin(x'+y')|$










      share|cite|improve this question











      $endgroup$




      $f(x,y)=left ( frac{1}{4}sin(x+y),1+frac{2}{3}arctan(x-y) right )$



      Prove that $f$ is a contraction



      $mathbb{R}^2$ is equipped with $d((x,y),(x',y'))=|x-x'|+|y-y'|$



      My problem is that I'm not able to find an upper bound of $|sin(x+y)-sin(x'+y')|$







      general-topology






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 16 at 3:29









      Andrews

      5191318




      5191318










      asked Jan 16 at 0:29









      Pedro AlvarèsPedro Alvarès

      636




      636






















          1 Answer
          1






          active

          oldest

          votes


















          0












          $begingroup$

          By MVT $|sin(A)-sin(B)|leq |A-B|$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            But A is a function of x and y
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37










          • $begingroup$
            Then what is ther derivative if sin(A)
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37











          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%2f3075170%2fproving-fx-y-left-frac14-sinxy-1-frac23-arctanx-y-right%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









          0












          $begingroup$

          By MVT $|sin(A)-sin(B)|leq |A-B|$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            But A is a function of x and y
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37










          • $begingroup$
            Then what is ther derivative if sin(A)
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37
















          0












          $begingroup$

          By MVT $|sin(A)-sin(B)|leq |A-B|$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            But A is a function of x and y
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37










          • $begingroup$
            Then what is ther derivative if sin(A)
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37














          0












          0








          0





          $begingroup$

          By MVT $|sin(A)-sin(B)|leq |A-B|$.






          share|cite|improve this answer









          $endgroup$



          By MVT $|sin(A)-sin(B)|leq |A-B|$.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Jan 16 at 0:32









          Kavi Rama MurthyKavi Rama Murthy

          61.6k42262




          61.6k42262












          • $begingroup$
            But A is a function of x and y
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37










          • $begingroup$
            Then what is ther derivative if sin(A)
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37


















          • $begingroup$
            But A is a function of x and y
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37










          • $begingroup$
            Then what is ther derivative if sin(A)
            $endgroup$
            – Pedro Alvarès
            Jan 16 at 0:37
















          $begingroup$
          But A is a function of x and y
          $endgroup$
          – Pedro Alvarès
          Jan 16 at 0:37




          $begingroup$
          But A is a function of x and y
          $endgroup$
          – Pedro Alvarès
          Jan 16 at 0:37












          $begingroup$
          Then what is ther derivative if sin(A)
          $endgroup$
          – Pedro Alvarès
          Jan 16 at 0:37




          $begingroup$
          Then what is ther derivative if sin(A)
          $endgroup$
          – Pedro Alvarès
          Jan 16 at 0:37


















          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%2f3075170%2fproving-fx-y-left-frac14-sinxy-1-frac23-arctanx-y-right%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

          'app-layout' is not a known element: how to share Component with different Modules

          android studio warns about leanback feature tag usage required on manifest while using Unity exported app?

          WPF add header to Image with URL pettitions [duplicate]