A limit that looks like e

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  • Опубліковано 24 кві 2024
  • In this video, I evaluated a limit that looked very much like e as n approached infinity. The journey simply led us to e.

КОМЕНТАРІ • 51

  • @___whateverr
    @___whateverr Місяць тому +6

    i solved it in my mind , and when i saw that you added ln i was so happy lol i felt like einstein thank you so much i love your channel

  • @meiwinspoi5080
    @meiwinspoi5080 Місяць тому +7

    just love your teaching. its like a rockstar teaching. so unreal because you are yourself. un pretentious. i am a teacher and how i wish i could do as well as you do.

  • @derrickbonsell
    @derrickbonsell Місяць тому +7

    You had me there with that n^2+n trick

  • @Mr._Nikola_Tesla
    @Mr._Nikola_Tesla Місяць тому +10

    Sir, I'm going to go ahead and say that you are the most wonderful teacher I've ever come across.
    Also I have this problem from one of my old math challenge books (I already know how to do it, I just want to see your approach to it) It goes like-
    "We know that 1^0 = 1, so we can say, 1^0 = 1^1, since the bases are same, we can drop the base to get 0 = 1, find how to disprove this."

    • @PrimeNewtons
      @PrimeNewtons  Місяць тому +1

      Nice question. Let me post it in the community.

    • @Jon60987
      @Jon60987 Місяць тому +1

      For the number 1, 1 to any power is 1. So the rule of dropping bases does not apply. The rule of dropping bases also does not apply to the number 0.

    • @Mr._Nikola_Tesla
      @Mr._Nikola_Tesla Місяць тому

      @@Jon60987 You are correct, that is how I did it. But I believe there is a mathematical way to show this as well

    • @Jon60987
      @Jon60987 Місяць тому

      @@Mr._Nikola_Tesla Take the natural log of both sides. If the base is > 1, or between 0 and 1, then you can divide both sides by ln of the base to get the powers being equal. If the base = 1, then ln 1 = 0 and you can not divide both sides by ln 1.

    • @Jon60987
      @Jon60987 Місяць тому

      So here is my attempt to write it here: x^y = x^z implies that ln (x^y) = ln (x^z) implies that y*ln x = z*ln x, and if x is between 0 and 1 or greater than 1 then you can divide both sides by ln x to get y = z..

  • @Mr._Nikola_Tesla
    @Mr._Nikola_Tesla Місяць тому +25

    A little typo you have in the title.

  • @sandyjr5225
    @sandyjr5225 Місяць тому +12

    Just curious, what's with the "Beware of dogs" caution at the end? It's a good caution though..

  • @Riazkhan12342
    @Riazkhan12342 Місяць тому +2

    Love from Pakistan 🇵🇰 ❤

  • @happyhippo4664
    @happyhippo4664 Місяць тому +7

    I got an email that the T-shirts will ship next month. That is great.

  • @user-xd8yu4wc5z
    @user-xd8yu4wc5z 9 днів тому +1

    Keep going man i love your videos

  • @Orillians
    @Orillians Місяць тому

    For a few days I was really bored and really did not want to watch your videos, but I watched one and now im binge watching all of the ones I missed lol

  • @Blaqjaqshellaq
    @Blaqjaqshellaq Місяць тому

    We now know what we'd only THOUGHT we knew...

    • @PrimeNewtons
      @PrimeNewtons  Місяць тому

      That's an accurate way to put it.

  • @vinayakmamtani
    @vinayakmamtani Місяць тому

    It is the format of (1+f(x))^g(x) or 1^infinity so we write it as e^f(x).g(x) and then solve it as a normal limit

  • @AlirezaNabavian-eu6fz
    @AlirezaNabavian-eu6fz Місяць тому

    Excellent

  • @nicolascamargo8339
    @nicolascamargo8339 Місяць тому

    Muy buena la explicación, detallada y clara

  • @epicmonke3319
    @epicmonke3319 Місяць тому

    Ah hell nah that look at 3:28 got me putting my ears up

  • @marcgriselhubert3915
    @marcgriselhubert3915 Місяць тому +1

    u(n) = [1 +(1/(n^2 +n)]^[n^2 + sqrt(n)] , so ln(u(n)) = [n^2 + sqrt(n)]. ln([1 + (1/(n^2 +n)])
    We use equivalents when n goes to +infinity: [n^2 + sqrt(n)] is equivalent to n^2 and ln([1 +(1/(n^2 +n)]) is equivalent to 1/(n^2 +n) or 1/n^2.
    So ln (u(n) is equivalent to n^2/n^2 = 1 and limit (ln(u(n)) = 1 and finally limit (u(n)) = e when n goes to +infinity.

  • @guidichris
    @guidichris Місяць тому

    Nice!!

  • @NotPVS
    @NotPVS Місяць тому

    I had a very intuitive idea to solve this question without solving the limit. We know that limx->infinity (1+1/x)^2x = e^2, so the ratio between the exponent and the one in the denominator is actually the exponent we need to the base e that we get after solving the limit! By finding the limit as x->infinity x^2+sqrt(x)/x^2+x = 1, we can prove that the expression is equal to e without much calculation. Remember, learn how to approach a problem not to solve it :)

  • @GreenMeansGOF
    @GreenMeansGOF Місяць тому +2

    My idea was to add and subtract n from the exponent but that may be more difficult.

    • @xinpingdonohoe3978
      @xinpingdonohoe3978 Місяць тому

      Mine too. Dealing with it may be more awkward since that n-√n doesn't divide too nicely into n²+n, to try and get more e stuff.

  • @omerdvir1709
    @omerdvir1709 Місяць тому

    I have a question. Could you take the limit to the base and the exponent in this case because you’d get the same answer but I don’t know if that’s just a lucky accident

  • @nothingbutmathproofs7150
    @nothingbutmathproofs7150 Місяць тому

    I am very surprised that that sqrt(n) didn't prevent the limit from being e. Nicely done.

    • @jacksonsmith2955
      @jacksonsmith2955 Місяць тому

      You shouldn't expect it to. With n -> infinity, the n^2 term will grow so much faster than the sqrt(n) term that it might as well not be there. Same with the n in n^2 + n. You only really need to pay attention to the part that grows the fastest when you have a limit going to infinity.
      Hell, you could take the limit of (1 + 1/[e^n + 2n^45])^(e^n + ln(n)^37) as n -> infinity and it would still be e, because the fastest growing term (e^n) trends towards infinity.

  • @adityashahi8184
    @adityashahi8184 Місяць тому +1

    Well the another idea of this question was very impressive but there is another one ..
    e^lim (n²+√n)(1 + 1/n²+n -1)
    And then the answer was e

  • @dean532
    @dean532 Місяць тому

    Last time I took a peak into what you thought about Gamma functions. Back in the day, We expressed a couple of Vector Calculus results in terms of Γ(n) and incidently β (n,x) How about sharing some thoughts on the mighty Bessel functions too in maybe your upcoming videos..

  • @cesarcampuzanomartinez8182
    @cesarcampuzanomartinez8182 Місяць тому

    Can you solve the twin prime conjecture next please 😊

  • @marcoghiotti7153
    @marcoghiotti7153 Місяць тому

    Would it then be possible to generalise to any other similar form? I guess we could.

    • @marcoghiotti7153
      @marcoghiotti7153 Місяць тому

      I think as long as the 2 polynomials have the same degree you can generalise, as the lim of their ratio will go to 1

  • @MrJasbur1
    @MrJasbur1 Місяць тому

    Hey, completely unrelated question. But does anyone know if Prime Newtons will do a video on number theory or discrete logarithms?

    • @PrimeNewtons
      @PrimeNewtons  Місяць тому

      Let me answer you here. The first 3 videos on this channel were on Number Theory. The audience for it is small. And you know, if they won't buy, don't sell is the the rule of UA-cam. I will soon begin making exclusive long videos but only for channel members. So I can at least make videos that are less popular.

  • @domanicmarcus2176
    @domanicmarcus2176 Місяць тому

    At time 5:47, why did you look to your right towards the ground.

  • @lovishnahar1807
    @lovishnahar1807 Місяць тому

    sir this question was asked in indian statistical institute exam once

  • @ruffifuffler8711
    @ruffifuffler8711 Місяць тому

    Turned into the prostate wrench uvula function;
    (ln((l((1+1/(z^2+z))^(z^2+z^(.5)))^88), l being parametric.

  • @michaelyu-jj8or
    @michaelyu-jj8or Місяць тому

    this question can be solved by squeese rule

  • @boguslawszostak1784
    @boguslawszostak1784 Місяць тому

    It is not true that the limit of the function is a function of the limit if the function is not continuous.
    The function x^a is continuous, so you can directly use this property without taking logarithms, which you just proved. If the continuous function g(x) has a limit y, then lim g(x)^h(x) = y^lim h(x).

  • @metalliron8821
    @metalliron8821 Місяць тому

    I have a challenge for you! to prove that lim x - > 2 of g(x) = { x^(2) if 0

  • @omograbi
    @omograbi Місяць тому

    6:27 sqrt(n)/n^2=n^(1/2)-n^(4/2)=n^(-3/2)=1/(n.sqrt(n))
    You've got this wrong here

  • @johnpaterson6112
    @johnpaterson6112 Місяць тому

    Rather obvious that in the limit the n^2 will dominate the n and sqrt (n), so the answer is e.

  • @thabisonathanielmoremi8017
    @thabisonathanielmoremi8017 Місяць тому

    Kindly check sqrt(n) /(n) ^2.