Arithmetic mean geometric mean inequality unclearproving inequality?Practicing the arithmetic-geometric means...

Do the temporary hit points from the Battlerager barbarian's Reckless Abandon stack if I make multiple attacks on my turn?

Was Spock the First Vulcan in Starfleet?

Why are there no referendums in the US?

Is expanding the research of a group into machine learning as a PhD student risky?

Is this apparent Class Action settlement a spam message?

Opposite of a diet

How can I kill an app using Terminal?

Is the destination of a commercial flight important for the pilot?

Implement the Thanos sorting algorithm

What is the intuitive meaning of having a linear relationship between the logs of two variables?

Return the Closest Prime Number

Arithmetic mean geometric mean inequality unclear

Is exact Kanji stroke length important?

Increase performance creating Mandelbrot set in python

What is the difference between "behavior" and "behaviour"?

How to run a prison with the smallest amount of guards?

Different result between scanning in Epson's "color negative film" mode and scanning in positive -> invert curve in post?

How does Loki do this?

How to Reset Passwords on Multiple Websites Easily?

How easy is it to start Magic from scratch?

Hostile work environment after whistle-blowing on coworker and our boss. What do I do?

Short story about space worker geeks who zone out by 'listening' to radiation from stars

System.debug(JSON.Serialize(o)) Not longer shows full string

How to pronounce the slash sign



Arithmetic mean geometric mean inequality unclear


proving inequality?Practicing the arithmetic-geometric means inequalityArithmetic Mean and Geometric Mean Question, Guidance NeededHow prove Reversing the Arithmetic mean – Geometric mean inequality?Mean Value Theorem and Inequality.Using arithmetic mean>geometric meanNesbitt's Inequality $frac{a}{b+c}+frac{b}{c+a}+frac{c}{a+b}geqfrac{3}{2}$Problem in Arithmetic Mean - Geometric Mean inequalityProving Cauchy-Schwarz with Arithmetic Geometric meanInequality involving a kind of Harmonic mean













2












$begingroup$


I know that the AM-GM inequality takes the form $$ frac{x + y}{2} geq sqrt{xy},$$ but I read in a book another form which is $$ frac{x^2 + y^2}{2} geq |xy|,$$ but I am wondering how the second comes from the first? could anyone explain this for me please?










share|cite|improve this question











$endgroup$

















    2












    $begingroup$


    I know that the AM-GM inequality takes the form $$ frac{x + y}{2} geq sqrt{xy},$$ but I read in a book another form which is $$ frac{x^2 + y^2}{2} geq |xy|,$$ but I am wondering how the second comes from the first? could anyone explain this for me please?










    share|cite|improve this question











    $endgroup$















      2












      2








      2


      1



      $begingroup$


      I know that the AM-GM inequality takes the form $$ frac{x + y}{2} geq sqrt{xy},$$ but I read in a book another form which is $$ frac{x^2 + y^2}{2} geq |xy|,$$ but I am wondering how the second comes from the first? could anyone explain this for me please?










      share|cite|improve this question











      $endgroup$




      I know that the AM-GM inequality takes the form $$ frac{x + y}{2} geq sqrt{xy},$$ but I read in a book another form which is $$ frac{x^2 + y^2}{2} geq |xy|,$$ but I am wondering how the second comes from the first? could anyone explain this for me please?







      calculus inequality






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited 5 hours ago









      Bernard

      123k741117




      123k741117










      asked 5 hours ago









      hopefullyhopefully

      279114




      279114






















          2 Answers
          2






          active

          oldest

          votes


















          6












          $begingroup$

          If you plug $x=X^2$, $y=Y^2$ into the first inequality you get
          $$frac{X^2+Y^2}{2} ge sqrt{X^2Y^2} = sqrt{(XY)^2}=|XY|,$$
          which is the second inequality (modulo capitalization).






          share|cite|improve this answer









          $endgroup$





















            5












            $begingroup$

            The AM-GM inequality for $n$ non-negative values is



            $frac1{n}(sum_{k=1}^n x_k)
            ge (prod_{k=1}^n x_k)^{1/n}
            $
            .



            This can be rewritten in two ways.



            First,
            by simple algebra,



            $(sum_{k=1}^n x_i)^n
            ge n^n(prod_{k=1}^n x_k)
            $
            .



            Second,
            letting $x_k = y_k^n$,
            this becomes



            $frac1{n}(sum_{k=1}^n y_k^n)
            ge prod_{k=1}^n y_k
            $
            .



            It is useful to recognize
            these disguises.






            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%2f3165273%2farithmetic-mean-geometric-mean-inequality-unclear%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









              6












              $begingroup$

              If you plug $x=X^2$, $y=Y^2$ into the first inequality you get
              $$frac{X^2+Y^2}{2} ge sqrt{X^2Y^2} = sqrt{(XY)^2}=|XY|,$$
              which is the second inequality (modulo capitalization).






              share|cite|improve this answer









              $endgroup$


















                6












                $begingroup$

                If you plug $x=X^2$, $y=Y^2$ into the first inequality you get
                $$frac{X^2+Y^2}{2} ge sqrt{X^2Y^2} = sqrt{(XY)^2}=|XY|,$$
                which is the second inequality (modulo capitalization).






                share|cite|improve this answer









                $endgroup$
















                  6












                  6








                  6





                  $begingroup$

                  If you plug $x=X^2$, $y=Y^2$ into the first inequality you get
                  $$frac{X^2+Y^2}{2} ge sqrt{X^2Y^2} = sqrt{(XY)^2}=|XY|,$$
                  which is the second inequality (modulo capitalization).






                  share|cite|improve this answer









                  $endgroup$



                  If you plug $x=X^2$, $y=Y^2$ into the first inequality you get
                  $$frac{X^2+Y^2}{2} ge sqrt{X^2Y^2} = sqrt{(XY)^2}=|XY|,$$
                  which is the second inequality (modulo capitalization).







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered 5 hours ago









                  jgonjgon

                  16k32143




                  16k32143























                      5












                      $begingroup$

                      The AM-GM inequality for $n$ non-negative values is



                      $frac1{n}(sum_{k=1}^n x_k)
                      ge (prod_{k=1}^n x_k)^{1/n}
                      $
                      .



                      This can be rewritten in two ways.



                      First,
                      by simple algebra,



                      $(sum_{k=1}^n x_i)^n
                      ge n^n(prod_{k=1}^n x_k)
                      $
                      .



                      Second,
                      letting $x_k = y_k^n$,
                      this becomes



                      $frac1{n}(sum_{k=1}^n y_k^n)
                      ge prod_{k=1}^n y_k
                      $
                      .



                      It is useful to recognize
                      these disguises.






                      share|cite|improve this answer









                      $endgroup$


















                        5












                        $begingroup$

                        The AM-GM inequality for $n$ non-negative values is



                        $frac1{n}(sum_{k=1}^n x_k)
                        ge (prod_{k=1}^n x_k)^{1/n}
                        $
                        .



                        This can be rewritten in two ways.



                        First,
                        by simple algebra,



                        $(sum_{k=1}^n x_i)^n
                        ge n^n(prod_{k=1}^n x_k)
                        $
                        .



                        Second,
                        letting $x_k = y_k^n$,
                        this becomes



                        $frac1{n}(sum_{k=1}^n y_k^n)
                        ge prod_{k=1}^n y_k
                        $
                        .



                        It is useful to recognize
                        these disguises.






                        share|cite|improve this answer









                        $endgroup$
















                          5












                          5








                          5





                          $begingroup$

                          The AM-GM inequality for $n$ non-negative values is



                          $frac1{n}(sum_{k=1}^n x_k)
                          ge (prod_{k=1}^n x_k)^{1/n}
                          $
                          .



                          This can be rewritten in two ways.



                          First,
                          by simple algebra,



                          $(sum_{k=1}^n x_i)^n
                          ge n^n(prod_{k=1}^n x_k)
                          $
                          .



                          Second,
                          letting $x_k = y_k^n$,
                          this becomes



                          $frac1{n}(sum_{k=1}^n y_k^n)
                          ge prod_{k=1}^n y_k
                          $
                          .



                          It is useful to recognize
                          these disguises.






                          share|cite|improve this answer









                          $endgroup$



                          The AM-GM inequality for $n$ non-negative values is



                          $frac1{n}(sum_{k=1}^n x_k)
                          ge (prod_{k=1}^n x_k)^{1/n}
                          $
                          .



                          This can be rewritten in two ways.



                          First,
                          by simple algebra,



                          $(sum_{k=1}^n x_i)^n
                          ge n^n(prod_{k=1}^n x_k)
                          $
                          .



                          Second,
                          letting $x_k = y_k^n$,
                          this becomes



                          $frac1{n}(sum_{k=1}^n y_k^n)
                          ge prod_{k=1}^n y_k
                          $
                          .



                          It is useful to recognize
                          these disguises.







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered 5 hours ago









                          marty cohenmarty cohen

                          74.9k549130




                          74.9k549130






























                              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%2f3165273%2farithmetic-mean-geometric-mean-inequality-unclear%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

                              El tren de la libertad Índice Antecedentes "Porque yo decido" Desarrollo de la...

                              Puerta de Hutt Referencias Enlaces externos Menú de navegación15°58′00″S 5°42′00″O /...

                              Castillo d'Acher Características Menú de navegación