Calculate a Line Integral of differentiable form of degree $1$.integral of a 2-form over an oriented...

Having the player face themselves after the mid-game

Was this cameo in Captain Marvel computer generated?

Is it appropriate to ask a former professor to order a library book for me through ILL?

Precision notation for voltmeters

Did Amazon pay $0 in taxes last year?

Giving a career talk in my old university, how prominently should I tell students my salary?

What should I do when a paper is published similar to my PhD thesis without citation?

Short story about cities being connected by a conveyor belt

Does the US political system, in principle, allow for a no-party system?

How spaceships determine each other's mass in space?

How do you use environments that have the same name within a single latex document?

When Central Limit Theorem breaks down

Ultrafilters as a double dual

Why aren't there more Gauls like Obelix?

How can I portion out frozen cookie dough?

Should I apply for my boss's promotion?

Insult for someone who "doesn't know anything"

How to write a chaotic neutral protagonist and prevent my readers from thinking they are evil?

How to make sure I'm assertive enough in contact with subordinates?

How does learning spells work when leveling a multiclass character?

Can I challenge the interviewer to give me a proper technical feedback?

If nine coins are tossed, what is the probability that the number of heads is even?

Help! My Character is too much for her story!

Why does a car's steering wheel get lighter with increasing speed



Calculate a Line Integral of differentiable form of degree $1$.


integral of a 2-form over an oriented manifoldUsing Stokes's theorem to calculate a value of integralDifferential forms and determinantsAn Integral InequalityProving a formula for the exterior derivative of a specific $k$-form, given in base representationCalculate the integral using Green's TheoremCalculate $domega$ of an $n-1$ forms $omega$$d(Iomega) + I(domega) = omega$ for differential formsCalculus with Differential Forms.$f^{*}omega = det(df)dx_{1}wedge cdots wedge dx_{n}$ for $f(x_{1},…,x_{n}) = (y_{1},…,y_{n})$ and $omega = dy_{1}wedge cdots dy_{n}$













1












$begingroup$



Show that the form $omega = 2xy^3dx + 3x^2y^2dy$ is closed and calculate $int_{c}omega$, where $c$ is given by $y=x^2$, $(0,0)$ to $(x,y)$.




My attempt.



$begin{eqnarray*}
domega &=& d(2xy^3)wedge dx + d(3x^2y^2)wedge dy\
&=& (2y^3dx + 6xy^2dy)wedge dx + (6xy^2dx + 6xy^2dy)dy\
& = & -6xy^2dxwedge dy + 6xy^2dxwedge dy\
&=& 0.
end{eqnarray*}$



Now, by definition



$$int_{c}omega = int_{a}^{b}left(sum_{i}a_{i}(t)frac{dx_{i}}{dt}right)dt$$



where $omega = sum_{i}a_{i}dx_{i}$. Then



$$sum_{i}a_{i}(t)frac{dx_{i}}{dt} = 2x(t)y(t)^3frac{dx}{dt} + 3x(t)^2y(t)^2frac{dy}{dt}.$$



We can write $c: [0,x] to {(x,x^2)}$ given by $c(t) = (t,t^2)$, by taking $x(t) = t$ and $y(t) = t^2$. So, we have



$begin{eqnarray*}
int_{c}omega &=& int_{0}^{x}left(2x(t)y(t)^3x'(t) + 3x(t)^2y(t)^2y'(t)right)dt\
&=& int_{0}^{x}2t^{7}dt + int_{0}^{x}6t^{7}dt\
& = & frac{t^{8}}{4}Bigg|_{0}^{x} + frac{3t^{8}}{4}Bigg|_{0}^{x}\
& = & t^{8}Bigg|_{0}^{x}\
&=& x^{8}
end{eqnarray*}$



Is correct? This is my first problem about Line Integrals on $1$-forms.










share|cite|improve this question









$endgroup$

















    1












    $begingroup$



    Show that the form $omega = 2xy^3dx + 3x^2y^2dy$ is closed and calculate $int_{c}omega$, where $c$ is given by $y=x^2$, $(0,0)$ to $(x,y)$.




    My attempt.



    $begin{eqnarray*}
    domega &=& d(2xy^3)wedge dx + d(3x^2y^2)wedge dy\
    &=& (2y^3dx + 6xy^2dy)wedge dx + (6xy^2dx + 6xy^2dy)dy\
    & = & -6xy^2dxwedge dy + 6xy^2dxwedge dy\
    &=& 0.
    end{eqnarray*}$



    Now, by definition



    $$int_{c}omega = int_{a}^{b}left(sum_{i}a_{i}(t)frac{dx_{i}}{dt}right)dt$$



    where $omega = sum_{i}a_{i}dx_{i}$. Then



    $$sum_{i}a_{i}(t)frac{dx_{i}}{dt} = 2x(t)y(t)^3frac{dx}{dt} + 3x(t)^2y(t)^2frac{dy}{dt}.$$



    We can write $c: [0,x] to {(x,x^2)}$ given by $c(t) = (t,t^2)$, by taking $x(t) = t$ and $y(t) = t^2$. So, we have



    $begin{eqnarray*}
    int_{c}omega &=& int_{0}^{x}left(2x(t)y(t)^3x'(t) + 3x(t)^2y(t)^2y'(t)right)dt\
    &=& int_{0}^{x}2t^{7}dt + int_{0}^{x}6t^{7}dt\
    & = & frac{t^{8}}{4}Bigg|_{0}^{x} + frac{3t^{8}}{4}Bigg|_{0}^{x}\
    & = & t^{8}Bigg|_{0}^{x}\
    &=& x^{8}
    end{eqnarray*}$



    Is correct? This is my first problem about Line Integrals on $1$-forms.










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$



      Show that the form $omega = 2xy^3dx + 3x^2y^2dy$ is closed and calculate $int_{c}omega$, where $c$ is given by $y=x^2$, $(0,0)$ to $(x,y)$.




      My attempt.



      $begin{eqnarray*}
      domega &=& d(2xy^3)wedge dx + d(3x^2y^2)wedge dy\
      &=& (2y^3dx + 6xy^2dy)wedge dx + (6xy^2dx + 6xy^2dy)dy\
      & = & -6xy^2dxwedge dy + 6xy^2dxwedge dy\
      &=& 0.
      end{eqnarray*}$



      Now, by definition



      $$int_{c}omega = int_{a}^{b}left(sum_{i}a_{i}(t)frac{dx_{i}}{dt}right)dt$$



      where $omega = sum_{i}a_{i}dx_{i}$. Then



      $$sum_{i}a_{i}(t)frac{dx_{i}}{dt} = 2x(t)y(t)^3frac{dx}{dt} + 3x(t)^2y(t)^2frac{dy}{dt}.$$



      We can write $c: [0,x] to {(x,x^2)}$ given by $c(t) = (t,t^2)$, by taking $x(t) = t$ and $y(t) = t^2$. So, we have



      $begin{eqnarray*}
      int_{c}omega &=& int_{0}^{x}left(2x(t)y(t)^3x'(t) + 3x(t)^2y(t)^2y'(t)right)dt\
      &=& int_{0}^{x}2t^{7}dt + int_{0}^{x}6t^{7}dt\
      & = & frac{t^{8}}{4}Bigg|_{0}^{x} + frac{3t^{8}}{4}Bigg|_{0}^{x}\
      & = & t^{8}Bigg|_{0}^{x}\
      &=& x^{8}
      end{eqnarray*}$



      Is correct? This is my first problem about Line Integrals on $1$-forms.










      share|cite|improve this question









      $endgroup$





      Show that the form $omega = 2xy^3dx + 3x^2y^2dy$ is closed and calculate $int_{c}omega$, where $c$ is given by $y=x^2$, $(0,0)$ to $(x,y)$.




      My attempt.



      $begin{eqnarray*}
      domega &=& d(2xy^3)wedge dx + d(3x^2y^2)wedge dy\
      &=& (2y^3dx + 6xy^2dy)wedge dx + (6xy^2dx + 6xy^2dy)dy\
      & = & -6xy^2dxwedge dy + 6xy^2dxwedge dy\
      &=& 0.
      end{eqnarray*}$



      Now, by definition



      $$int_{c}omega = int_{a}^{b}left(sum_{i}a_{i}(t)frac{dx_{i}}{dt}right)dt$$



      where $omega = sum_{i}a_{i}dx_{i}$. Then



      $$sum_{i}a_{i}(t)frac{dx_{i}}{dt} = 2x(t)y(t)^3frac{dx}{dt} + 3x(t)^2y(t)^2frac{dy}{dt}.$$



      We can write $c: [0,x] to {(x,x^2)}$ given by $c(t) = (t,t^2)$, by taking $x(t) = t$ and $y(t) = t^2$. So, we have



      $begin{eqnarray*}
      int_{c}omega &=& int_{0}^{x}left(2x(t)y(t)^3x'(t) + 3x(t)^2y(t)^2y'(t)right)dt\
      &=& int_{0}^{x}2t^{7}dt + int_{0}^{x}6t^{7}dt\
      & = & frac{t^{8}}{4}Bigg|_{0}^{x} + frac{3t^{8}}{4}Bigg|_{0}^{x}\
      & = & t^{8}Bigg|_{0}^{x}\
      &=& x^{8}
      end{eqnarray*}$



      Is correct? This is my first problem about Line Integrals on $1$-forms.







      real-analysis integration differential-forms






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked yesterday









      Lucas CorrêaLucas Corrêa

      1,6321321




      1,6321321






















          1 Answer
          1






          active

          oldest

          votes


















          1












          $begingroup$

          The differential form is even exact:
          $$
          omega = 2xy^3,dx + 3x^2y^2,dy
          = frac{partial(x^2y^3)}{partial x} dx + frac{partial(x^2y^3)}{partial y} dy
          = d(x^2y^3).
          $$

          From this follows that $omega$ is closed, since $d^2omega = 0$ for any differential form $omega.$



          Therefore we can calculate the integral as
          $$
          int_c omega
          = int_{(0,0)}^{(x,x^2)} d(x^2y^3)
          = x^2y^3 {Bigg|}_{(0,0)}^{(x,x^2)}
          = x^2(x^2)^3 - 0^2 cdot 0^3
          = x^8.
          $$



          Thus, your result is correct.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you! Your approach is very clever!
            $endgroup$
            – Lucas Corrêa
            yesterday











          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%2f3139355%2fcalculate-a-line-integral-of-differentiable-form-of-degree-1%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









          1












          $begingroup$

          The differential form is even exact:
          $$
          omega = 2xy^3,dx + 3x^2y^2,dy
          = frac{partial(x^2y^3)}{partial x} dx + frac{partial(x^2y^3)}{partial y} dy
          = d(x^2y^3).
          $$

          From this follows that $omega$ is closed, since $d^2omega = 0$ for any differential form $omega.$



          Therefore we can calculate the integral as
          $$
          int_c omega
          = int_{(0,0)}^{(x,x^2)} d(x^2y^3)
          = x^2y^3 {Bigg|}_{(0,0)}^{(x,x^2)}
          = x^2(x^2)^3 - 0^2 cdot 0^3
          = x^8.
          $$



          Thus, your result is correct.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you! Your approach is very clever!
            $endgroup$
            – Lucas Corrêa
            yesterday
















          1












          $begingroup$

          The differential form is even exact:
          $$
          omega = 2xy^3,dx + 3x^2y^2,dy
          = frac{partial(x^2y^3)}{partial x} dx + frac{partial(x^2y^3)}{partial y} dy
          = d(x^2y^3).
          $$

          From this follows that $omega$ is closed, since $d^2omega = 0$ for any differential form $omega.$



          Therefore we can calculate the integral as
          $$
          int_c omega
          = int_{(0,0)}^{(x,x^2)} d(x^2y^3)
          = x^2y^3 {Bigg|}_{(0,0)}^{(x,x^2)}
          = x^2(x^2)^3 - 0^2 cdot 0^3
          = x^8.
          $$



          Thus, your result is correct.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you! Your approach is very clever!
            $endgroup$
            – Lucas Corrêa
            yesterday














          1












          1








          1





          $begingroup$

          The differential form is even exact:
          $$
          omega = 2xy^3,dx + 3x^2y^2,dy
          = frac{partial(x^2y^3)}{partial x} dx + frac{partial(x^2y^3)}{partial y} dy
          = d(x^2y^3).
          $$

          From this follows that $omega$ is closed, since $d^2omega = 0$ for any differential form $omega.$



          Therefore we can calculate the integral as
          $$
          int_c omega
          = int_{(0,0)}^{(x,x^2)} d(x^2y^3)
          = x^2y^3 {Bigg|}_{(0,0)}^{(x,x^2)}
          = x^2(x^2)^3 - 0^2 cdot 0^3
          = x^8.
          $$



          Thus, your result is correct.






          share|cite|improve this answer









          $endgroup$



          The differential form is even exact:
          $$
          omega = 2xy^3,dx + 3x^2y^2,dy
          = frac{partial(x^2y^3)}{partial x} dx + frac{partial(x^2y^3)}{partial y} dy
          = d(x^2y^3).
          $$

          From this follows that $omega$ is closed, since $d^2omega = 0$ for any differential form $omega.$



          Therefore we can calculate the integral as
          $$
          int_c omega
          = int_{(0,0)}^{(x,x^2)} d(x^2y^3)
          = x^2y^3 {Bigg|}_{(0,0)}^{(x,x^2)}
          = x^2(x^2)^3 - 0^2 cdot 0^3
          = x^8.
          $$



          Thus, your result is correct.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered yesterday









          md2perpemd2perpe

          8,21111028




          8,21111028












          • $begingroup$
            Thank you! Your approach is very clever!
            $endgroup$
            – Lucas Corrêa
            yesterday


















          • $begingroup$
            Thank you! Your approach is very clever!
            $endgroup$
            – Lucas Corrêa
            yesterday
















          $begingroup$
          Thank you! Your approach is very clever!
          $endgroup$
          – Lucas Corrêa
          yesterday




          $begingroup$
          Thank you! Your approach is very clever!
          $endgroup$
          – Lucas Corrêa
          yesterday


















          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%2f3139355%2fcalculate-a-line-integral-of-differentiable-form-of-degree-1%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

          Nidaros erkebispedøme

          Birsay

          Where did Arya get these scars? Unicorn Meta Zoo #1: Why another podcast? Announcing the arrival of Valued Associate #679: Cesar Manara Favourite questions and answers from the 1st quarter of 2019Why did Arya refuse to end it?Has the pronunciation of Arya Stark's name changed?Has Arya forgiven people?Why did Arya Stark lose her vision?Why can Arya still use the faces?Has the Narrow Sea become narrower?Does Arya Stark know how to make poisons outside of the House of Black and White?Why did Nymeria leave Arya?Why did Arya not kill the Lannister soldiers she encountered in the Riverlands?What is the current canonical age of Sansa, Bran and Arya Stark?