Mod-01 Lec-36 Calculus of Variations - Three Lemmas and a Theorem

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  • Опубликовано: 29 мар 2015
  • Introduction to CFD by Prof M. Ramakrishna,Department of Aerospace Engineering,IIT Madras.For more details on NPTEL visit nptel.ac.in

Комментарии • 18

  • @GoutamDAS-ls1wb
    @GoutamDAS-ls1wb 3 года назад

    Excellent lectures--I wish I had you for my math classes. It took me a long time (I am 57+) but learning this lesson from Prof Ramakrishna was so gratifying. Thank you so very much for posting this on RUclips

  • @vivekkoul4428
    @vivekkoul4428 4 года назад +1

    A mind blowing teacher!!! So cool!! Exceptional lecture👍👍👍🙏

  • @sivaramasamy7489
    @sivaramasamy7489 6 лет назад +2

    What a lecture, exceptional

  • @vivekkoul4428
    @vivekkoul4428 4 года назад +1

    Where can I find the other lectures of the same series?

  • @emilioarguello9786
    @emilioarguello9786 Год назад

    Can anyone point me to the lecture where Professor Ramakrishna talks about Taylor Series. I would very much appreciate it.

  • @vivekkoul4428
    @vivekkoul4428 4 года назад

    My doubt is in the 1st lemma : if alpha(x) = 0 then whole integral will be zero no, because anything multiplied by zero is zero only.

  • @shalmam6372
    @shalmam6372 4 года назад

    I think u are a genius

  • @fosheimdet
    @fosheimdet 5 лет назад

    But at 12:24 you can still pick a alpha(x) such that the integral is zero. Just make it a sinus curve with a period of x2-x1 and a phase such that it is zero at x1. Am I missing something?

    • @jehushaphat
      @jehushaphat 4 года назад +1

      The issue is, would the integral be GUARANTEED to be zero for ANY h(x) i give you? The answer is no.

    • @redouanehemi9693
      @redouanehemi9693 4 года назад

      @@jehushaphat thnks for u both

  • @GoutamDAS-ls1wb
    @GoutamDAS-ls1wb 3 года назад

    If h(x) = sin(x) and the interval is [0, 2*pi]; then we know that integral( sin(x)cos(x) dx) in the interval = 0 but that does not mean cos(x) = 0 everywhere?? Can someone please clarify?

    • @claudiocan41
      @claudiocan41 3 года назад

      cos(x) is right for sin(x), and satisfy the integlal, but dosen't work for all the functions in C. Remember that you are working with a space of functions and the condition have to work every posible function in C. a(x)=0 satisfy the condition for every h(x) in C.

    • @GoutamDAS-ls1wb
      @GoutamDAS-ls1wb 3 года назад +1

      ​@@claudiocan41 I figured that out reading the Lemma very carefully. I wish this was emphasized in the lemma and the case of orthogonal functions discussed. But I guess mathematicians read very carefully because ideas are represented very succinctly. I am a 57+ lifelong learner trying to learn advanced math on my own. No mathematicians in my social circle and so your response was invaluable--thanx a bunch!

    • @claudiocan41
      @claudiocan41 3 года назад

      @@GoutamDAS-ls1wb That's nice. Any case, do you know why the second lemma is general for any function ? I know that the derivation is right but why chosing that h(x) works for every function in C1

    • @GoutamDAS-ls1wb
      @GoutamDAS-ls1wb 3 года назад

      @@claudiocan41 Thank you for your prompt response. It is great RUclips allows people from all across the world to assist each other. I am in the process of understanding the second lemma. Thanks a bunch once again!

    • @GoutamDAS-ls1wb
      @GoutamDAS-ls1wb 3 года назад +1

      @@claudiocan41 I understand the second lemma now. I would have done it differently--using integration by parts and then using Lemma_1 to show that since (alpha(x))' would have to be zero then alpha(x) must be a constant.

  • @albertogotta4983
    @albertogotta4983 8 лет назад

    che ce frega de leo messi noi c'avemo padoiiiiiin!