The Jacobian of $(x,y)mapsto (x+y^2,y+x^2)$ under the substitution $u=x+y^2$ and $v=y+x^2$.












-2












$begingroup$


I am given the map $(x,y)mapsto (x+y^2,y+x^2)$. I am unable to find the Jacobian by making the substitution $u=x+y^2$ and $v=y+x^2$. Any hints would be appreciated.



(I am trying to find whether the map is area preserving? I know "the map $f:mathbb{R}^ntomathbb{R}^n$ is area and orientation preserving iff the determinant of the Jacobian is $pm1$".)










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    What is the definition of Jacobian?
    $endgroup$
    – zoidberg
    Dec 9 '18 at 2:39
















-2












$begingroup$


I am given the map $(x,y)mapsto (x+y^2,y+x^2)$. I am unable to find the Jacobian by making the substitution $u=x+y^2$ and $v=y+x^2$. Any hints would be appreciated.



(I am trying to find whether the map is area preserving? I know "the map $f:mathbb{R}^ntomathbb{R}^n$ is area and orientation preserving iff the determinant of the Jacobian is $pm1$".)










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    What is the definition of Jacobian?
    $endgroup$
    – zoidberg
    Dec 9 '18 at 2:39














-2












-2








-2





$begingroup$


I am given the map $(x,y)mapsto (x+y^2,y+x^2)$. I am unable to find the Jacobian by making the substitution $u=x+y^2$ and $v=y+x^2$. Any hints would be appreciated.



(I am trying to find whether the map is area preserving? I know "the map $f:mathbb{R}^ntomathbb{R}^n$ is area and orientation preserving iff the determinant of the Jacobian is $pm1$".)










share|cite|improve this question











$endgroup$




I am given the map $(x,y)mapsto (x+y^2,y+x^2)$. I am unable to find the Jacobian by making the substitution $u=x+y^2$ and $v=y+x^2$. Any hints would be appreciated.



(I am trying to find whether the map is area preserving? I know "the map $f:mathbb{R}^ntomathbb{R}^n$ is area and orientation preserving iff the determinant of the Jacobian is $pm1$".)







multivariable-calculus transformation area






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 9 '18 at 2:32









Shaun

9,000113682




9,000113682










asked Dec 9 '18 at 1:56









Yadati KiranYadati Kiran

1,769619




1,769619








  • 1




    $begingroup$
    What is the definition of Jacobian?
    $endgroup$
    – zoidberg
    Dec 9 '18 at 2:39














  • 1




    $begingroup$
    What is the definition of Jacobian?
    $endgroup$
    – zoidberg
    Dec 9 '18 at 2:39








1




1




$begingroup$
What is the definition of Jacobian?
$endgroup$
– zoidberg
Dec 9 '18 at 2:39




$begingroup$
What is the definition of Jacobian?
$endgroup$
– zoidberg
Dec 9 '18 at 2:39










1 Answer
1






active

oldest

votes


















0












$begingroup$

The Jacobian of a multivariable function $f:mathbb{R}^2 rightarrow mathbb{R}^2$ such that $f(x,y)=(u(x,y),v(x,y))$ is:



$$textbf{J}(f(x,y)) = detbegin{pmatrix}
frac{partial u}{partial x} & frac{partial u}{partial y} \
frac{partial v}{partial x} & frac{partial v}{partial y} \
end{pmatrix}$$



where $det$ denotes the determinant of the matrix.



Calculating the partial derivatives of $u(x,y)=x+y^2$ and $v(x,y)=y+x^2$ we have that the Jacobian of your given function is:



$$detbegin{pmatrix}
1 & 2y \
2x & 1 \
end{pmatrix}=1-4xy$$






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%2f3031914%2fthe-jacobian-of-x-y-mapsto-xy2-yx2-under-the-substitution-u-xy2-an%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












    $begingroup$

    The Jacobian of a multivariable function $f:mathbb{R}^2 rightarrow mathbb{R}^2$ such that $f(x,y)=(u(x,y),v(x,y))$ is:



    $$textbf{J}(f(x,y)) = detbegin{pmatrix}
    frac{partial u}{partial x} & frac{partial u}{partial y} \
    frac{partial v}{partial x} & frac{partial v}{partial y} \
    end{pmatrix}$$



    where $det$ denotes the determinant of the matrix.



    Calculating the partial derivatives of $u(x,y)=x+y^2$ and $v(x,y)=y+x^2$ we have that the Jacobian of your given function is:



    $$detbegin{pmatrix}
    1 & 2y \
    2x & 1 \
    end{pmatrix}=1-4xy$$






    share|cite|improve this answer











    $endgroup$


















      0












      $begingroup$

      The Jacobian of a multivariable function $f:mathbb{R}^2 rightarrow mathbb{R}^2$ such that $f(x,y)=(u(x,y),v(x,y))$ is:



      $$textbf{J}(f(x,y)) = detbegin{pmatrix}
      frac{partial u}{partial x} & frac{partial u}{partial y} \
      frac{partial v}{partial x} & frac{partial v}{partial y} \
      end{pmatrix}$$



      where $det$ denotes the determinant of the matrix.



      Calculating the partial derivatives of $u(x,y)=x+y^2$ and $v(x,y)=y+x^2$ we have that the Jacobian of your given function is:



      $$detbegin{pmatrix}
      1 & 2y \
      2x & 1 \
      end{pmatrix}=1-4xy$$






      share|cite|improve this answer











      $endgroup$
















        0












        0








        0





        $begingroup$

        The Jacobian of a multivariable function $f:mathbb{R}^2 rightarrow mathbb{R}^2$ such that $f(x,y)=(u(x,y),v(x,y))$ is:



        $$textbf{J}(f(x,y)) = detbegin{pmatrix}
        frac{partial u}{partial x} & frac{partial u}{partial y} \
        frac{partial v}{partial x} & frac{partial v}{partial y} \
        end{pmatrix}$$



        where $det$ denotes the determinant of the matrix.



        Calculating the partial derivatives of $u(x,y)=x+y^2$ and $v(x,y)=y+x^2$ we have that the Jacobian of your given function is:



        $$detbegin{pmatrix}
        1 & 2y \
        2x & 1 \
        end{pmatrix}=1-4xy$$






        share|cite|improve this answer











        $endgroup$



        The Jacobian of a multivariable function $f:mathbb{R}^2 rightarrow mathbb{R}^2$ such that $f(x,y)=(u(x,y),v(x,y))$ is:



        $$textbf{J}(f(x,y)) = detbegin{pmatrix}
        frac{partial u}{partial x} & frac{partial u}{partial y} \
        frac{partial v}{partial x} & frac{partial v}{partial y} \
        end{pmatrix}$$



        where $det$ denotes the determinant of the matrix.



        Calculating the partial derivatives of $u(x,y)=x+y^2$ and $v(x,y)=y+x^2$ we have that the Jacobian of your given function is:



        $$detbegin{pmatrix}
        1 & 2y \
        2x & 1 \
        end{pmatrix}=1-4xy$$







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Dec 9 '18 at 3:45

























        answered Dec 9 '18 at 3:20









        MAXMAX

        19218




        19218






























            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%2f3031914%2fthe-jacobian-of-x-y-mapsto-xy2-yx2-under-the-substitution-u-xy2-an%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

            Quarter-circle Tiles

            build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

            Mont Emei