Confused by an unusual form of Taylor's theorem The 2019 Stack Overflow Developer Survey Results Are InTaylor's Theorem Problemprove or disprove an inequality on bounds of derivatives for radial functionsTaylor's Theorem expansionImage of Jordan measurable set under a diffeomorphism.A different form of Taylor's TheoremStrange form of Taylor's Theorem for linearizationCoherence between Hamiltonian and Lagrangian in form of an inequality (Evans PDE)A closed form for $int_0^pi lvert sin(m t) cos(n t) rvert , mathrmd t$Taylor's formula and multi-indices

How to save as into a customized destination on macOS?

Why is the maximum length of OpenWrt’s root password 8 characters?

Where to refill my bottle in India?

What does ひと匙 mean in this manga and has it been used colloquially?

How to support a colleague who finds meetings extremely tiring?

How to manage monthly salary

Why isn't the circumferential light around the M87 black hole's event horizon symmetric?

Is flight data recorder erased after every flight?

Right tool to dig six foot holes?

What to do when moving next to a bird sanctuary with a loosely-domesticated cat?

Why can Shazam fly?

How technical should a Scrum Master be to effectively remove impediments?

Pokemon Turn Based battle (Python)

Output the Arecibo Message

Did 3000BC Egyptians use meteoric iron weapons?

Reference request: Oldest number theory books with (unsolved) exercises?

How come people say “Would of”?

What could be the right powersource for 15 seconds lifespan disposable giant chainsaw?

Return to UK after being refused entry years previously

What are the motivations for publishing new editions of an existing textbook, beyond new discoveries in a field?

Deal with toxic manager when you can't quit

Does a dangling wire really electrocute me if I'm standing in water?

Loose spokes after only a few rides

Lightning Grid - Columns and Rows?



Confused by an unusual form of Taylor's theorem



The 2019 Stack Overflow Developer Survey Results Are InTaylor's Theorem Problemprove or disprove an inequality on bounds of derivatives for radial functionsTaylor's Theorem expansionImage of Jordan measurable set under a diffeomorphism.A different form of Taylor's TheoremStrange form of Taylor's Theorem for linearizationCoherence between Hamiltonian and Lagrangian in form of an inequality (Evans PDE)A closed form for $int_0^pi lvert sin(m t) cos(n t) rvert , mathrmd t$Taylor's formula and multi-indices










0












$begingroup$


I'm reading up on manifolds and encountered this proposition:




If $g:mathbbR^ntomathbbR$ is a $C^k$ function ($kgeq 2$) on some convex open subset $UsubseteqmathbbR^n$ about $pinmathbbR^n$, then for every $qin U$ we have
$$g(q)=g(p) + partial_ig rvert_p(q_i-p_i) + (q_i-p_i)(q_j-p_j)int_0^1partial_i,j^2 grvert_(1-t)p+tq,dt$$
in the Einstein summation notation, where the integral is a function $h:UtomathbbR$ of $q$. In particular, when $k=infty$, i.e. $g$ is smooth, so too is the integral $h$.




I'm familiar with the following form of Taylor's theorem, in multi-index notation:




beginalign
f(vecx) &= f(veca) +
sum_1leq lvert alpha rvertleq k (D^alphaf)(veca)(vecx-veca)^alpha \ &+
sum_lvertalpharvertleq k+1 dfrack+1alpha!(vecx-veca)^alpha int_0^1 (1-t)^k (D^alphaf) left( (1-t)veca + tvecx right),dt
endalign




It would seem that the first proposition is truncating the terms in the second involving derivatives of order higher than 2. How are the two results related and/or how does the first follow from the second?










share|cite|improve this question









$endgroup$
















    0












    $begingroup$


    I'm reading up on manifolds and encountered this proposition:




    If $g:mathbbR^ntomathbbR$ is a $C^k$ function ($kgeq 2$) on some convex open subset $UsubseteqmathbbR^n$ about $pinmathbbR^n$, then for every $qin U$ we have
    $$g(q)=g(p) + partial_ig rvert_p(q_i-p_i) + (q_i-p_i)(q_j-p_j)int_0^1partial_i,j^2 grvert_(1-t)p+tq,dt$$
    in the Einstein summation notation, where the integral is a function $h:UtomathbbR$ of $q$. In particular, when $k=infty$, i.e. $g$ is smooth, so too is the integral $h$.




    I'm familiar with the following form of Taylor's theorem, in multi-index notation:




    beginalign
    f(vecx) &= f(veca) +
    sum_1leq lvert alpha rvertleq k (D^alphaf)(veca)(vecx-veca)^alpha \ &+
    sum_lvertalpharvertleq k+1 dfrack+1alpha!(vecx-veca)^alpha int_0^1 (1-t)^k (D^alphaf) left( (1-t)veca + tvecx right),dt
    endalign




    It would seem that the first proposition is truncating the terms in the second involving derivatives of order higher than 2. How are the two results related and/or how does the first follow from the second?










    share|cite|improve this question









    $endgroup$














      0












      0








      0





      $begingroup$


      I'm reading up on manifolds and encountered this proposition:




      If $g:mathbbR^ntomathbbR$ is a $C^k$ function ($kgeq 2$) on some convex open subset $UsubseteqmathbbR^n$ about $pinmathbbR^n$, then for every $qin U$ we have
      $$g(q)=g(p) + partial_ig rvert_p(q_i-p_i) + (q_i-p_i)(q_j-p_j)int_0^1partial_i,j^2 grvert_(1-t)p+tq,dt$$
      in the Einstein summation notation, where the integral is a function $h:UtomathbbR$ of $q$. In particular, when $k=infty$, i.e. $g$ is smooth, so too is the integral $h$.




      I'm familiar with the following form of Taylor's theorem, in multi-index notation:




      beginalign
      f(vecx) &= f(veca) +
      sum_1leq lvert alpha rvertleq k (D^alphaf)(veca)(vecx-veca)^alpha \ &+
      sum_lvertalpharvertleq k+1 dfrack+1alpha!(vecx-veca)^alpha int_0^1 (1-t)^k (D^alphaf) left( (1-t)veca + tvecx right),dt
      endalign




      It would seem that the first proposition is truncating the terms in the second involving derivatives of order higher than 2. How are the two results related and/or how does the first follow from the second?










      share|cite|improve this question









      $endgroup$




      I'm reading up on manifolds and encountered this proposition:




      If $g:mathbbR^ntomathbbR$ is a $C^k$ function ($kgeq 2$) on some convex open subset $UsubseteqmathbbR^n$ about $pinmathbbR^n$, then for every $qin U$ we have
      $$g(q)=g(p) + partial_ig rvert_p(q_i-p_i) + (q_i-p_i)(q_j-p_j)int_0^1partial_i,j^2 grvert_(1-t)p+tq,dt$$
      in the Einstein summation notation, where the integral is a function $h:UtomathbbR$ of $q$. In particular, when $k=infty$, i.e. $g$ is smooth, so too is the integral $h$.




      I'm familiar with the following form of Taylor's theorem, in multi-index notation:




      beginalign
      f(vecx) &= f(veca) +
      sum_1leq lvert alpha rvertleq k (D^alphaf)(veca)(vecx-veca)^alpha \ &+
      sum_lvertalpharvertleq k+1 dfrack+1alpha!(vecx-veca)^alpha int_0^1 (1-t)^k (D^alphaf) left( (1-t)veca + tvecx right),dt
      endalign




      It would seem that the first proposition is truncating the terms in the second involving derivatives of order higher than 2. How are the two results related and/or how does the first follow from the second?







      calculus taylor-expansion






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Mar 23 at 18:05









      terrygarciaterrygarcia

      17211




      17211




















          0






          active

          oldest

          votes












          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%2f3159648%2fconfused-by-an-unusual-form-of-taylors-theorem%23new-answer', 'question_page');

          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes















          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%2f3159648%2fconfused-by-an-unusual-form-of-taylors-theorem%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

          How should I support this large drywall patch? Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern) Announcing the arrival of Valued Associate #679: Cesar Manara Unicorn Meta Zoo #1: Why another podcast?How do I cover large gaps in drywall?How do I keep drywall around a patch from crumbling?Can I glue a second layer of drywall?How to patch long strip on drywall?Large drywall patch: how to avoid bulging seams?Drywall Mesh Patch vs. Bulge? To remove or not to remove?How to fix this drywall job?Prep drywall before backsplashWhat's the best way to fix this horrible drywall patch job?Drywall patching using 3M Patch Plus Primer

          random experiment with two different functions on unit interval Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)Random variable and probability space notionsRandom Walk with EdgesFinding functions where the increase over a random interval is Poisson distributedNumber of days until dayCan an observed event in fact be of zero probability?Unit random processmodels of coins and uniform distributionHow to get the number of successes given $n$ trials , probability $P$ and a random variable $X$Absorbing Markov chain in a computer. Is “almost every” turned into always convergence in computer executions?Stopped random walk is not uniformly integrable

          Lowndes Grove History Architecture References Navigation menu32°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661132°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661178002500"National Register Information System"Historic houses of South Carolina"Lowndes Grove""+32° 48' 6.00", −79° 57' 58.00""Lowndes Grove, Charleston County (260 St. Margaret St., Charleston)""Lowndes Grove"The Charleston ExpositionIt Happened in South Carolina"Lowndes Grove (House), Saint Margaret Street & Sixth Avenue, Charleston, Charleston County, SC(Photographs)"Plantations of the Carolina Low Countrye