Maximize the following equation under a constraint












1












$begingroup$


Maximize $g(x,y)=x^4+y^4$ on $x^2+y^2=9$.



Our professor had sped through it and I didn't fully understand how they arrived at the answer. Some clarification on it would be greatly appreciated. I have attached the writing below:



enter image description here










share|cite|improve this question











$endgroup$

















    1












    $begingroup$


    Maximize $g(x,y)=x^4+y^4$ on $x^2+y^2=9$.



    Our professor had sped through it and I didn't fully understand how they arrived at the answer. Some clarification on it would be greatly appreciated. I have attached the writing below:



    enter image description here










    share|cite|improve this question











    $endgroup$















      1












      1








      1





      $begingroup$


      Maximize $g(x,y)=x^4+y^4$ on $x^2+y^2=9$.



      Our professor had sped through it and I didn't fully understand how they arrived at the answer. Some clarification on it would be greatly appreciated. I have attached the writing below:



      enter image description here










      share|cite|improve this question











      $endgroup$




      Maximize $g(x,y)=x^4+y^4$ on $x^2+y^2=9$.



      Our professor had sped through it and I didn't fully understand how they arrived at the answer. Some clarification on it would be greatly appreciated. I have attached the writing below:



      enter image description here







      multivariable-calculus






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 22 at 0:58









      David G. Stork

      11k41432




      11k41432










      asked Jan 21 at 23:25









      Random StudentRandom Student

      443




      443






















          2 Answers
          2






          active

          oldest

          votes


















          2












          $begingroup$

          $g(x,y) = x^4 + y^4 = x^4 + underbrace{big(sqrt{9-x^2}big)^4}_{from~constraint} = g(x)$



          $${d g(x) over d x} = 4 x^3-4 x left(9-x^2right) = 4x left( x^2 - left(9-x^2right) right) = 4 x^2 (2 x^2 - 9)$$



          Set this function of a single variable $x$ to equal $0$ (for an extremum) and thus find:



          $$left{{xto 0},left{xto -frac{3}{sqrt{2}}right},left{xto frac{3}{sqrt{2}}right}right}$$



          Then test each individually to see if it is a maximum, minimum or inflection point. (You can also calculate second-order derivatives to solve that problem, or plot the functions...)



          enter image description here



          It is clear that $x=0$ corresponds to a local maximum, while the other solutions correspond to local minima.



          By the way, the handwritten notes say "obviously $(0,0)$ is a minimum," which is false. That point does not obey the constraints and is hence invalid.






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            I'm sorry, I still can't quite understand, the values that you received are the max on the boundary of the graph or just random points on the graph? I'm quite new at this.
            $endgroup$
            – Random Student
            Jan 21 at 23:51












          • $begingroup$
            This approach misses the local extrema at $y=0$.
            $endgroup$
            – random
            Jan 22 at 12:46












          • $begingroup$
            @random: Huh? When $y=0$, $x=pm 3$.
            $endgroup$
            – David G. Stork
            Jan 22 at 17:33










          • $begingroup$
            From the symmetries in the original problem it follows that the local maximum of $g(x,y)$ at $(0,3)$ implies the existence of the same local maximum at $(3,0)$ and $(-3,0)$. The chosen parameterization of the upper half of the circle does show them by the value of g(x) at $x=-3$ and $x=3$, but the value of $g'(x)$ at those points is misleading.
            $endgroup$
            – random
            Jan 23 at 0:39





















          0












          $begingroup$

          Since we are finding a maximum on a circle centered at the origin it makes sense to convert both equations to polar coordinates:



          begin{eqnarray} g(r,theta)&=&(rcostheta)^4+(rsintheta)^4\
          &=&r^4(cos^4theta+sin^4theta)\
          frac{dg}{dr}&=&4r^3(cos^4theta+sin^4theta)=0\
          frac{dg}{dtheta}&=&-4r^4cos^3thetasintheta+4r^4sin^3thetacostheta\
          &=&-4r^4sinthetacostheta(cos^2theta-sin^2theta)\
          &=&-2r^4(2sinthetacostheta)(cos^2theta-sin^2theta)\
          &=&-2r^4sin(2theta)cos(2theta)\
          &=&-r^4sin(4theta)=0
          end{eqnarray}



          So extrema should occur when $sin(4theta)=0$. And $sin(4theta)=0$ only when $4theta$ is a whole multiple of $pi$. Thus you must check points of the circle corresponding to multiples of $dfrac{pi}{4}$.



          You should find that the minima occur when $theta$ is an odd multiple of $dfrac{pi}{4}$ and the maxima will occur when $theta$ is an even multiple of $dfrac{pi}{4}$ (i.e. a multiple of $dfrac{pi}{2})$.



          $$gleft(3,frac{pi}{4}right)=gleft(3,frac{3pi}{4}right)=gleft(3,frac{5pi}{4}right)=gleft(3,frac{7pi}{4}right)=left(pmfrac{3}{sqrt{2}}right)^4+left(pmfrac{3}{sqrt{2}}right)^4=frac{81}{2}$$



          $$g(3,0)=gleft(3,frac{pi}{2}right)=gleft(3,piright)=gleft(3,frac{3pi}{2}right)=3^4=81$$






          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%2f3082550%2fmaximize-the-following-equation-under-a-constraint%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









            2












            $begingroup$

            $g(x,y) = x^4 + y^4 = x^4 + underbrace{big(sqrt{9-x^2}big)^4}_{from~constraint} = g(x)$



            $${d g(x) over d x} = 4 x^3-4 x left(9-x^2right) = 4x left( x^2 - left(9-x^2right) right) = 4 x^2 (2 x^2 - 9)$$



            Set this function of a single variable $x$ to equal $0$ (for an extremum) and thus find:



            $$left{{xto 0},left{xto -frac{3}{sqrt{2}}right},left{xto frac{3}{sqrt{2}}right}right}$$



            Then test each individually to see if it is a maximum, minimum or inflection point. (You can also calculate second-order derivatives to solve that problem, or plot the functions...)



            enter image description here



            It is clear that $x=0$ corresponds to a local maximum, while the other solutions correspond to local minima.



            By the way, the handwritten notes say "obviously $(0,0)$ is a minimum," which is false. That point does not obey the constraints and is hence invalid.






            share|cite|improve this answer











            $endgroup$













            • $begingroup$
              I'm sorry, I still can't quite understand, the values that you received are the max on the boundary of the graph or just random points on the graph? I'm quite new at this.
              $endgroup$
              – Random Student
              Jan 21 at 23:51












            • $begingroup$
              This approach misses the local extrema at $y=0$.
              $endgroup$
              – random
              Jan 22 at 12:46












            • $begingroup$
              @random: Huh? When $y=0$, $x=pm 3$.
              $endgroup$
              – David G. Stork
              Jan 22 at 17:33










            • $begingroup$
              From the symmetries in the original problem it follows that the local maximum of $g(x,y)$ at $(0,3)$ implies the existence of the same local maximum at $(3,0)$ and $(-3,0)$. The chosen parameterization of the upper half of the circle does show them by the value of g(x) at $x=-3$ and $x=3$, but the value of $g'(x)$ at those points is misleading.
              $endgroup$
              – random
              Jan 23 at 0:39


















            2












            $begingroup$

            $g(x,y) = x^4 + y^4 = x^4 + underbrace{big(sqrt{9-x^2}big)^4}_{from~constraint} = g(x)$



            $${d g(x) over d x} = 4 x^3-4 x left(9-x^2right) = 4x left( x^2 - left(9-x^2right) right) = 4 x^2 (2 x^2 - 9)$$



            Set this function of a single variable $x$ to equal $0$ (for an extremum) and thus find:



            $$left{{xto 0},left{xto -frac{3}{sqrt{2}}right},left{xto frac{3}{sqrt{2}}right}right}$$



            Then test each individually to see if it is a maximum, minimum or inflection point. (You can also calculate second-order derivatives to solve that problem, or plot the functions...)



            enter image description here



            It is clear that $x=0$ corresponds to a local maximum, while the other solutions correspond to local minima.



            By the way, the handwritten notes say "obviously $(0,0)$ is a minimum," which is false. That point does not obey the constraints and is hence invalid.






            share|cite|improve this answer











            $endgroup$













            • $begingroup$
              I'm sorry, I still can't quite understand, the values that you received are the max on the boundary of the graph or just random points on the graph? I'm quite new at this.
              $endgroup$
              – Random Student
              Jan 21 at 23:51












            • $begingroup$
              This approach misses the local extrema at $y=0$.
              $endgroup$
              – random
              Jan 22 at 12:46












            • $begingroup$
              @random: Huh? When $y=0$, $x=pm 3$.
              $endgroup$
              – David G. Stork
              Jan 22 at 17:33










            • $begingroup$
              From the symmetries in the original problem it follows that the local maximum of $g(x,y)$ at $(0,3)$ implies the existence of the same local maximum at $(3,0)$ and $(-3,0)$. The chosen parameterization of the upper half of the circle does show them by the value of g(x) at $x=-3$ and $x=3$, but the value of $g'(x)$ at those points is misleading.
              $endgroup$
              – random
              Jan 23 at 0:39
















            2












            2








            2





            $begingroup$

            $g(x,y) = x^4 + y^4 = x^4 + underbrace{big(sqrt{9-x^2}big)^4}_{from~constraint} = g(x)$



            $${d g(x) over d x} = 4 x^3-4 x left(9-x^2right) = 4x left( x^2 - left(9-x^2right) right) = 4 x^2 (2 x^2 - 9)$$



            Set this function of a single variable $x$ to equal $0$ (for an extremum) and thus find:



            $$left{{xto 0},left{xto -frac{3}{sqrt{2}}right},left{xto frac{3}{sqrt{2}}right}right}$$



            Then test each individually to see if it is a maximum, minimum or inflection point. (You can also calculate second-order derivatives to solve that problem, or plot the functions...)



            enter image description here



            It is clear that $x=0$ corresponds to a local maximum, while the other solutions correspond to local minima.



            By the way, the handwritten notes say "obviously $(0,0)$ is a minimum," which is false. That point does not obey the constraints and is hence invalid.






            share|cite|improve this answer











            $endgroup$



            $g(x,y) = x^4 + y^4 = x^4 + underbrace{big(sqrt{9-x^2}big)^4}_{from~constraint} = g(x)$



            $${d g(x) over d x} = 4 x^3-4 x left(9-x^2right) = 4x left( x^2 - left(9-x^2right) right) = 4 x^2 (2 x^2 - 9)$$



            Set this function of a single variable $x$ to equal $0$ (for an extremum) and thus find:



            $$left{{xto 0},left{xto -frac{3}{sqrt{2}}right},left{xto frac{3}{sqrt{2}}right}right}$$



            Then test each individually to see if it is a maximum, minimum or inflection point. (You can also calculate second-order derivatives to solve that problem, or plot the functions...)



            enter image description here



            It is clear that $x=0$ corresponds to a local maximum, while the other solutions correspond to local minima.



            By the way, the handwritten notes say "obviously $(0,0)$ is a minimum," which is false. That point does not obey the constraints and is hence invalid.







            share|cite|improve this answer














            share|cite|improve this answer



            share|cite|improve this answer








            edited Jan 22 at 1:18

























            answered Jan 21 at 23:32









            David G. StorkDavid G. Stork

            11k41432




            11k41432












            • $begingroup$
              I'm sorry, I still can't quite understand, the values that you received are the max on the boundary of the graph or just random points on the graph? I'm quite new at this.
              $endgroup$
              – Random Student
              Jan 21 at 23:51












            • $begingroup$
              This approach misses the local extrema at $y=0$.
              $endgroup$
              – random
              Jan 22 at 12:46












            • $begingroup$
              @random: Huh? When $y=0$, $x=pm 3$.
              $endgroup$
              – David G. Stork
              Jan 22 at 17:33










            • $begingroup$
              From the symmetries in the original problem it follows that the local maximum of $g(x,y)$ at $(0,3)$ implies the existence of the same local maximum at $(3,0)$ and $(-3,0)$. The chosen parameterization of the upper half of the circle does show them by the value of g(x) at $x=-3$ and $x=3$, but the value of $g'(x)$ at those points is misleading.
              $endgroup$
              – random
              Jan 23 at 0:39




















            • $begingroup$
              I'm sorry, I still can't quite understand, the values that you received are the max on the boundary of the graph or just random points on the graph? I'm quite new at this.
              $endgroup$
              – Random Student
              Jan 21 at 23:51












            • $begingroup$
              This approach misses the local extrema at $y=0$.
              $endgroup$
              – random
              Jan 22 at 12:46












            • $begingroup$
              @random: Huh? When $y=0$, $x=pm 3$.
              $endgroup$
              – David G. Stork
              Jan 22 at 17:33










            • $begingroup$
              From the symmetries in the original problem it follows that the local maximum of $g(x,y)$ at $(0,3)$ implies the existence of the same local maximum at $(3,0)$ and $(-3,0)$. The chosen parameterization of the upper half of the circle does show them by the value of g(x) at $x=-3$ and $x=3$, but the value of $g'(x)$ at those points is misleading.
              $endgroup$
              – random
              Jan 23 at 0:39


















            $begingroup$
            I'm sorry, I still can't quite understand, the values that you received are the max on the boundary of the graph or just random points on the graph? I'm quite new at this.
            $endgroup$
            – Random Student
            Jan 21 at 23:51






            $begingroup$
            I'm sorry, I still can't quite understand, the values that you received are the max on the boundary of the graph or just random points on the graph? I'm quite new at this.
            $endgroup$
            – Random Student
            Jan 21 at 23:51














            $begingroup$
            This approach misses the local extrema at $y=0$.
            $endgroup$
            – random
            Jan 22 at 12:46






            $begingroup$
            This approach misses the local extrema at $y=0$.
            $endgroup$
            – random
            Jan 22 at 12:46














            $begingroup$
            @random: Huh? When $y=0$, $x=pm 3$.
            $endgroup$
            – David G. Stork
            Jan 22 at 17:33




            $begingroup$
            @random: Huh? When $y=0$, $x=pm 3$.
            $endgroup$
            – David G. Stork
            Jan 22 at 17:33












            $begingroup$
            From the symmetries in the original problem it follows that the local maximum of $g(x,y)$ at $(0,3)$ implies the existence of the same local maximum at $(3,0)$ and $(-3,0)$. The chosen parameterization of the upper half of the circle does show them by the value of g(x) at $x=-3$ and $x=3$, but the value of $g'(x)$ at those points is misleading.
            $endgroup$
            – random
            Jan 23 at 0:39






            $begingroup$
            From the symmetries in the original problem it follows that the local maximum of $g(x,y)$ at $(0,3)$ implies the existence of the same local maximum at $(3,0)$ and $(-3,0)$. The chosen parameterization of the upper half of the circle does show them by the value of g(x) at $x=-3$ and $x=3$, but the value of $g'(x)$ at those points is misleading.
            $endgroup$
            – random
            Jan 23 at 0:39













            0












            $begingroup$

            Since we are finding a maximum on a circle centered at the origin it makes sense to convert both equations to polar coordinates:



            begin{eqnarray} g(r,theta)&=&(rcostheta)^4+(rsintheta)^4\
            &=&r^4(cos^4theta+sin^4theta)\
            frac{dg}{dr}&=&4r^3(cos^4theta+sin^4theta)=0\
            frac{dg}{dtheta}&=&-4r^4cos^3thetasintheta+4r^4sin^3thetacostheta\
            &=&-4r^4sinthetacostheta(cos^2theta-sin^2theta)\
            &=&-2r^4(2sinthetacostheta)(cos^2theta-sin^2theta)\
            &=&-2r^4sin(2theta)cos(2theta)\
            &=&-r^4sin(4theta)=0
            end{eqnarray}



            So extrema should occur when $sin(4theta)=0$. And $sin(4theta)=0$ only when $4theta$ is a whole multiple of $pi$. Thus you must check points of the circle corresponding to multiples of $dfrac{pi}{4}$.



            You should find that the minima occur when $theta$ is an odd multiple of $dfrac{pi}{4}$ and the maxima will occur when $theta$ is an even multiple of $dfrac{pi}{4}$ (i.e. a multiple of $dfrac{pi}{2})$.



            $$gleft(3,frac{pi}{4}right)=gleft(3,frac{3pi}{4}right)=gleft(3,frac{5pi}{4}right)=gleft(3,frac{7pi}{4}right)=left(pmfrac{3}{sqrt{2}}right)^4+left(pmfrac{3}{sqrt{2}}right)^4=frac{81}{2}$$



            $$g(3,0)=gleft(3,frac{pi}{2}right)=gleft(3,piright)=gleft(3,frac{3pi}{2}right)=3^4=81$$






            share|cite|improve this answer











            $endgroup$


















              0












              $begingroup$

              Since we are finding a maximum on a circle centered at the origin it makes sense to convert both equations to polar coordinates:



              begin{eqnarray} g(r,theta)&=&(rcostheta)^4+(rsintheta)^4\
              &=&r^4(cos^4theta+sin^4theta)\
              frac{dg}{dr}&=&4r^3(cos^4theta+sin^4theta)=0\
              frac{dg}{dtheta}&=&-4r^4cos^3thetasintheta+4r^4sin^3thetacostheta\
              &=&-4r^4sinthetacostheta(cos^2theta-sin^2theta)\
              &=&-2r^4(2sinthetacostheta)(cos^2theta-sin^2theta)\
              &=&-2r^4sin(2theta)cos(2theta)\
              &=&-r^4sin(4theta)=0
              end{eqnarray}



              So extrema should occur when $sin(4theta)=0$. And $sin(4theta)=0$ only when $4theta$ is a whole multiple of $pi$. Thus you must check points of the circle corresponding to multiples of $dfrac{pi}{4}$.



              You should find that the minima occur when $theta$ is an odd multiple of $dfrac{pi}{4}$ and the maxima will occur when $theta$ is an even multiple of $dfrac{pi}{4}$ (i.e. a multiple of $dfrac{pi}{2})$.



              $$gleft(3,frac{pi}{4}right)=gleft(3,frac{3pi}{4}right)=gleft(3,frac{5pi}{4}right)=gleft(3,frac{7pi}{4}right)=left(pmfrac{3}{sqrt{2}}right)^4+left(pmfrac{3}{sqrt{2}}right)^4=frac{81}{2}$$



              $$g(3,0)=gleft(3,frac{pi}{2}right)=gleft(3,piright)=gleft(3,frac{3pi}{2}right)=3^4=81$$






              share|cite|improve this answer











              $endgroup$
















                0












                0








                0





                $begingroup$

                Since we are finding a maximum on a circle centered at the origin it makes sense to convert both equations to polar coordinates:



                begin{eqnarray} g(r,theta)&=&(rcostheta)^4+(rsintheta)^4\
                &=&r^4(cos^4theta+sin^4theta)\
                frac{dg}{dr}&=&4r^3(cos^4theta+sin^4theta)=0\
                frac{dg}{dtheta}&=&-4r^4cos^3thetasintheta+4r^4sin^3thetacostheta\
                &=&-4r^4sinthetacostheta(cos^2theta-sin^2theta)\
                &=&-2r^4(2sinthetacostheta)(cos^2theta-sin^2theta)\
                &=&-2r^4sin(2theta)cos(2theta)\
                &=&-r^4sin(4theta)=0
                end{eqnarray}



                So extrema should occur when $sin(4theta)=0$. And $sin(4theta)=0$ only when $4theta$ is a whole multiple of $pi$. Thus you must check points of the circle corresponding to multiples of $dfrac{pi}{4}$.



                You should find that the minima occur when $theta$ is an odd multiple of $dfrac{pi}{4}$ and the maxima will occur when $theta$ is an even multiple of $dfrac{pi}{4}$ (i.e. a multiple of $dfrac{pi}{2})$.



                $$gleft(3,frac{pi}{4}right)=gleft(3,frac{3pi}{4}right)=gleft(3,frac{5pi}{4}right)=gleft(3,frac{7pi}{4}right)=left(pmfrac{3}{sqrt{2}}right)^4+left(pmfrac{3}{sqrt{2}}right)^4=frac{81}{2}$$



                $$g(3,0)=gleft(3,frac{pi}{2}right)=gleft(3,piright)=gleft(3,frac{3pi}{2}right)=3^4=81$$






                share|cite|improve this answer











                $endgroup$



                Since we are finding a maximum on a circle centered at the origin it makes sense to convert both equations to polar coordinates:



                begin{eqnarray} g(r,theta)&=&(rcostheta)^4+(rsintheta)^4\
                &=&r^4(cos^4theta+sin^4theta)\
                frac{dg}{dr}&=&4r^3(cos^4theta+sin^4theta)=0\
                frac{dg}{dtheta}&=&-4r^4cos^3thetasintheta+4r^4sin^3thetacostheta\
                &=&-4r^4sinthetacostheta(cos^2theta-sin^2theta)\
                &=&-2r^4(2sinthetacostheta)(cos^2theta-sin^2theta)\
                &=&-2r^4sin(2theta)cos(2theta)\
                &=&-r^4sin(4theta)=0
                end{eqnarray}



                So extrema should occur when $sin(4theta)=0$. And $sin(4theta)=0$ only when $4theta$ is a whole multiple of $pi$. Thus you must check points of the circle corresponding to multiples of $dfrac{pi}{4}$.



                You should find that the minima occur when $theta$ is an odd multiple of $dfrac{pi}{4}$ and the maxima will occur when $theta$ is an even multiple of $dfrac{pi}{4}$ (i.e. a multiple of $dfrac{pi}{2})$.



                $$gleft(3,frac{pi}{4}right)=gleft(3,frac{3pi}{4}right)=gleft(3,frac{5pi}{4}right)=gleft(3,frac{7pi}{4}right)=left(pmfrac{3}{sqrt{2}}right)^4+left(pmfrac{3}{sqrt{2}}right)^4=frac{81}{2}$$



                $$g(3,0)=gleft(3,frac{pi}{2}right)=gleft(3,piright)=gleft(3,frac{3pi}{2}right)=3^4=81$$







                share|cite|improve this answer














                share|cite|improve this answer



                share|cite|improve this answer








                edited Jan 26 at 20:37

























                answered Jan 22 at 0:15









                John Wayland BalesJohn Wayland Bales

                14.5k21238




                14.5k21238






























                    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%2f3082550%2fmaximize-the-following-equation-under-a-constraint%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

                    Mario Kart Wii

                    What does “Dominus providebit” mean?

                    Antonio Litta Visconti Arese