Proving a Sequence Converges Advanced Calculus Example

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  • Опубліковано 24 гру 2024

КОМЕНТАРІ • 25

  • @TheMathSorcerer
    @TheMathSorcerer  9 років тому +2

  • @crm321
    @crm321 Рік тому

    I'm not sure how the last inequality follows at 2:07. What if n = 1? Then 4/sqrt(n) + 2/n = 4/sqrt(n) + 2/sqrt(n) instead of being less than.

  • @roshnipatel3649
    @roshnipatel3649 4 роки тому +2

    at 2:00 why don't you square root the top number as well? why only the n?

  • @harleendiaries
    @harleendiaries 4 роки тому +2

    At 6:17, shouldn't it be only 'less than' instead of 'less than equal to' ?

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +2

      No because if n is 1 they are equal., more importantly though even if n is not 1 you can still put less than or equal to since it's weaker to be safe, remember less than or equal to does mean less than....or....equal to, so if you use it, it does mean less than but also allows for equality😃

    • @harleendiaries
      @harleendiaries 4 роки тому +2

      So quick to reply! 😊😊 Thank you so much!! Love your work and the way of teaching. 😌

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +1

      Thank you! Your question was good👍👍

  • @mmeixner5051
    @mmeixner5051 4 роки тому +1

    Does capital 'N' have to be a positive integer? I'm using Analysis: with introduction to proof by Lay, and he writes that a sequence converges provided that for each epsilon > 0, there exists a real number 'N' such that for any natural number 'n', n > N implies that | s_n - s | < epsilon.

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому

      That's fine that is an acceptable definition you can show it's equivalent to the one I used. I've seen others too slight variations.

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому

      Good question I can see why it would bother you, I don't like the variation in definitions either lol, math is already hard. It happens a lot too in other areas of math.

    • @mmeixner5051
      @mmeixner5051 4 роки тому +1

      ​@@TheMathSorcerer Thank you! I've seen 'N' defined as a positive integer more often (Rudin, Pugh, Krantz), so I'll probably stick with that. And actually, I looked at a newer edition of Lay's Analysis (I was using the 4th, and I looked at the 5th), and the definition was changed so that 'N' is also defined as a positive integer.

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому

      Oh interesting

    • @Realisation404
      @Realisation404 4 роки тому

      @@TheMathSorcerer Sir in the sequence ( -1) ^n . I set epsilon as 2 and solved. At the end I got limit of sequence value within a range. But when i take epsilon ≤ 1 I don't get any intersection. Why so? Plz reply

  • @dangerousangel777
    @dangerousangel777 4 роки тому +1

    HELP!!!!! What are the n's for and where do they relate and why do they matter???

    • @dangerousangel777
      @dangerousangel777 4 роки тому +1

      more specifically why is n>N and what is n I know capital N is a Natural number (thanks for using Z+ btw....the less N's the better....)

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +1

      Little n is an integer 😄 ya lots of n's lol

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +2

      Try this vid instead it's better I think ua-cam.com/video/b0i-DP-4Xbs/v-deo.html also there are more in my advanced calculus playlist😄😄

  • @sundaymanali5854
    @sundaymanali5854 Рік тому

    idk why we had to add 1 tho. otherwise great explanation

  • @ElizaberthUndEugen
    @ElizaberthUndEugen 7 років тому +2

    I don't see how your +1 thing is necessary... n needs to be greater than (6/eps)^2. As these are sequences were are dealing with n needs to be greater than the next integer greater or equal to (6/eps)^2. That integer is ceil((6/eps)^2). I don't see where we need the +1 in that.

    • @chdfnh
      @chdfnh 6 років тому +1

      He could use the Archimedean property and there is no need of ceiling function

    • @dangerousangel777
      @dangerousangel777 4 роки тому

      @@HT-on5sk how did he know (6/E)^2 + 1 was an integer? lol Help.
      If E^2 > 36 then isn't it not an integer?
      .......

    • @dangerousangel777
      @dangerousangel777 4 роки тому

      Nevermind, figured it out, the ceiling thingy! Lol

  • @dinisgds
    @dinisgds 6 років тому +1

    The sound volume is low.

  • @BrianTheMacaw
    @BrianTheMacaw 7 років тому

    poop