Integrate x^-x dx

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  • Опубліковано 8 вер 2024
  • When U-sub did not work at first I imediately knew it would take some advanced calculus to figure out. It ended up being as expected.

КОМЕНТАРІ • 133

  • @jmmc6219
    @jmmc6219 Місяць тому +153

    It feels like I am watching a Mathematical opera when ever I watch your videos. The drama! The suspense! Bravo 👏

    • @dannysigurdson7108
      @dannysigurdson7108 21 день тому

      Meanwhile I feel like I'm being tied down and mathematically sodomized

  • @Modo942000
    @Modo942000 Місяць тому +91

    It's really interesting how the integration of the original function between 0 and 1 ends up being equal to the infinite discrete sum of the same function starting from 1. I'm not sure why but it just feels fascinating that something like this exists.

    • @letao12
      @letao12 25 днів тому +8

      I got the same feeling. There must be some interesting symmetry.
      On the other hand, I also feel like the answer isn't any more helpful than the original question 🤣

    • @user-nv4wb6el2c
      @user-nv4wb6el2c 20 днів тому +1

      I can think of the Riemann integral from the shape of the function and the intervals of the integral and series, but I can’t quite come up with a way to express the Riemann sum properly.

  • @tessfra7695
    @tessfra7695 Місяць тому +82

    I really like that sir shows it's OK to back track & re-think when we reach a road block in solving

    • @kevinbush4300
      @kevinbush4300 Місяць тому +1

      Yes, it's very reassuring

    • @user-iw8dj6yw9y
      @user-iw8dj6yw9y Місяць тому

      He sees the future that we have never, as of yet, seen, then he backtracks.

    • @sovietwizard1620
      @sovietwizard1620 Місяць тому +2

      Yes I agree, but I think this is very common in calculus especially.

    • @tessfra7695
      @tessfra7695 Місяць тому +2

      I subscribe to a few other maths channels..all of them just show the right way(s) of getting to the ans..here, we get to understand WHY a particular way won't work, & how to get around/through/above the block..much appreciated!

  • @madushansamudika4543
    @madushansamudika4543 Місяць тому +16

    "Never stop learning.If you stop learning. Stop living..." I appreciate you very much.. Nice explanation and nice question..

    • @ranae6566
      @ranae6566 26 днів тому +3

      I think it’s “those who stop learning stop living”. Not to be nitpicky but changing “those” to “if” makes it sound like you’re suggesting suicide if they stop learning😂

    • @madushansamudika4543
      @madushansamudika4543 26 днів тому

      @@ranae6566 learning means not only studies..

  • @davidtallent8161
    @davidtallent8161 26 днів тому +5

    Excellent teacher! It is so refreshing to experience mathematics taught well. His enthusiasm and knowledge makes the difficult easy.😊

  • @BartBuzz
    @BartBuzz Місяць тому +22

    Watching this video was mesmerizing! Now, I want to know what that infinite series converges to.

    • @PrimeNewtons
      @PrimeNewtons  Місяць тому +28

      1.29129

    • @BartBuzz
      @BartBuzz Місяць тому +20

      @@PrimeNewtons Thanks! I'm 79 and still learning!

    • @geertfdevries9518
      @geertfdevries9518 27 днів тому +1

      do a spreadsheet, it converges very fast, after some six terms to 1.291286

    • @ahalfemptycup
      @ahalfemptycup 21 день тому

      I appreciate you all's scientific curiosity, but what is the point of computing the numerical value of a converging series if you can't prove its convergence, can't write it in simple terms usually involving natural numbers and usual constants and without having a manual method of solving the series.

    • @eng954
      @eng954 16 днів тому +1

      @@BartBuzz Same here..i am 70.

  • @stevebeal73
    @stevebeal73 Місяць тому +11

    I just loved this and your whole approach. As a 74 year old UK guy who took his BSc in 1971, I am indeed still learning. Thank you!

    • @johnclymo3668
      @johnclymo3668 Місяць тому +4

      I thought your comment was good to see that at your age you are still learning . I am sure the education system has changed since you were at uni.

  • @smftrsddvjiou6443
    @smftrsddvjiou6443 Місяць тому +17

    Wow, did not expect that is so complicated.

  • @asparkdeity8717
    @asparkdeity8717 Місяць тому +13

    It really feels like a Sophomore’s Dream!

  • @Al-Shorman
    @Al-Shorman Місяць тому +14

    And the sum from (k=1) to ∞ of [k^(-k)] = 1.29128599706
    and thx for the great video

  • @arantheo8607
    @arantheo8607 Місяць тому +3

    Clear and detailed explanation of the steps taken to tackle the problem , thank you , opera writer !

  • @eng954
    @eng954 16 днів тому +2

    As an ex calculus private teacher i appreciate your expression so much.Your english and explanation is so clear.

  • @renesperb
    @renesperb Місяць тому +8

    You do a very good job explaining the solution.The result is really nice.

  • @VenkateshSundararajan-tr6ve
    @VenkateshSundararajan-tr6ve 27 днів тому +4

    very beutifully done. i just love the way you put up an act of a few fumble here and there - fumbling like any average student would. Please do a video on tests for convergence. the answer for this integral converges to approx 1.29129. i would have preferred if you had finished off the video with a quick evaluation of the infinite sum - may be calculating 5 or 6 terms to show how quickly this converges. from a student perspective she is going to demand the value of the infinite sum at the final answer. ofcourse if i were the techer i would have said “thats left as an exercise”😅😅😅

  • @dangernuke929
    @dangernuke929 Місяць тому +15

    That was spectacular! Beautifully done!

  • @peterpeter4134
    @peterpeter4134 Місяць тому +4

    Excellent explanation! You are even better than some math professors!🎉

  • @alt_account4866
    @alt_account4866 26 днів тому +3

    Really good video! Even though I'm not that good with math, I find you videos really understandable!

  • @zealous2835
    @zealous2835 Місяць тому +2

    Man I aspire to understand math this well one day. I don’t know how to do any of this but the way you work and alter the math so intricately is beautiful

  • @kquat7899
    @kquat7899 22 дні тому +1

    Sloane's constant ~ 1.29...

  • @malayrojak
    @malayrojak 17 днів тому +1

    Well the ending was a Revelation! Thanks for sharing!

  • @Jeremy-i1d
    @Jeremy-i1d 26 днів тому +1

    Thank you for another wonderful video and what a beautiful and fascinating result.
    As an alternative approach. I had the idea of trying to compute the Riemann sum for the integral:
    Lim as n tends to infinity of
    the sum from r = 1 to n of
    1/n*(r/n)^~(r/n)
    directly. But so far I have not been able to do this.
    I also had the idea of proving the result you found by considering the difference between this sum, re expressed in the form:
    lim as n terns to infinity of the sum from r = 1 to n of r^-r
    and the above Riemann sum
    This is potentially easier I think, by establishing an upper bound, in terms of n, on the mod of this difference, and then showing that this bound is 0 in the limit as n terms to infinity. But so far I have not been able to do this either.
    I would be interested if you or others know if either of these alternative approaches can be made to work for this particular problem.
    Again, than you for your blessed and inspirational videos ❤

  • @tangential-research-ql5yd
    @tangential-research-ql5yd 14 днів тому

    Pleasant videos! I'll have to spend some hours to understand all the details here, but I think I'll set aside an evening for just that!

  • @THESHAURYASHUKLA
    @THESHAURYASHUKLA 24 дні тому +1

    Sir ,I am from India ,preparing for JEE exam which is an entrance exam to get into IITs which are just like MITs of India,I am currently in 12th standard and I really loved ur approach towards this problem which seems easy at first sight but is quite difficult ❤The exam for which I am preparing also asks quite difficult problems ,thanks for the Video ,Love from 🇮🇳🇮🇳🥰🥰
    U got a new sub.

    • @aalekhjain2682
      @aalekhjain2682 22 дні тому

      JEE Advanced doesn't ask this level of calculus imo

    • @THESHAURYASHUKLA
      @THESHAURYASHUKLA 15 днів тому

      @@aalekhjain2682 bro I have done these kind of probs which r bit out of syllabus but only for timepass or entertainment purpose. So chill,I m jee 2025 aspirant btw 😁

    • @aalekhjain2682
      @aalekhjain2682 15 днів тому

      @@THESHAURYASHUKLA oh nice, i am JEE 2026 aspirant 😁

  • @tanelkagan
    @tanelkagan 19 днів тому +2

    Fascinating video about the process but I'm not quite sure what we achieved - given the form of the solution looks so very similar to the original integral 🤔

    • @Grecks75
      @Grecks75 6 днів тому +1

      In terms of computing the integral's value? Not much (if anything at all). But the result looks very interesting _because_ of the similarity.

  • @marasw
    @marasw 22 дні тому +1

    most intellectual 20 minutes & 36 seconds of my life. Thanks

  • @epsilonxyzt
    @epsilonxyzt Місяць тому +1

    Never Stop Teaching!

  • @MinhNguyen-ij5md
    @MinhNguyen-ij5md 6 днів тому +1

    Not sure that I understood everything but it's awesome!

  • @markorletsky5976
    @markorletsky5976 21 день тому +1

    That made my Sunday evening pleasant.

  • @AndrejPanjkov
    @AndrejPanjkov 23 дні тому +1

    I'd approach it via the lambert W function. If that pays off, then your result gives an interesting expansion for W(x)

  • @joefreiburg2716
    @joefreiburg2716 22 дні тому

    Einfach genial!! Und so was von unterhaltsam 🙂 (Genius and best Entertainment!!)

  • @kallek9645
    @kallek9645 25 днів тому

    Top quality! Grateful for this teaching!

  • @ultrasteamcarpetcleaning3207
    @ultrasteamcarpetcleaning3207 Місяць тому

    WOW!! Outstanding!! I did not foresee a Gamma Function was going to be applied.

  • @sammtanX
    @sammtanX Місяць тому +3

    keep spreading the Revelation! Hail Him, The Almighty Glory.

  • @ManojkantSamal
    @ManojkantSamal 17 днів тому

    {1/(-x+1)}.(x)^(-x+1)
    The upper limit
    (1/0).(x)^0=infinite
    Lower limit
    1.x=x=0
    Infinite -0=infinite

  • @johnplong3644
    @johnplong3644 Місяць тому

    I have not done calculus in over 40 years .This is beyond what I am currently capable of doing.I am College level Algebra I couldn’t pass pre-calculus / Trigonometry right now .

  • @user-eb5dt9ln9g
    @user-eb5dt9ln9g День тому +1

    God this is epic

  • @Naomi_stephy
    @Naomi_stephy Місяць тому

    Hooooo , hermoso , me quedé pegada viendo, que lindas son las matemáticas❤

  • @Toldasor
    @Toldasor 29 днів тому

    Very interesting problem and clear explanation. Also you have such a lovely voice

    • @geertfdevries9518
      @geertfdevries9518 27 днів тому +1

      and such perfect handwriting on blackboard ! A joy to behold.

  • @user-yg2yi6gy3c
    @user-yg2yi6gy3c Місяць тому +1

    me don't understand anything but just wants to watch it

  • @johanneshagel3609
    @johanneshagel3609 25 днів тому

    Thank you, this was a perfect presentation, congratulations! One question still remains: Is there a closed expression for
    sum_(k=1)^infinity(k^(-k)) ? It can easily numerically be computet but the question would be, if this number can be expressed as a multiple of pi , e or whatever. Would be very interesting to know!

  • @Misteribel
    @Misteribel Місяць тому +2

    So, we go from one over x to the x, and the integral from 0 to 1 of that equals the sum of k=1 to infinity of k to the minus k, which is one over k to the k. But what does this approximate? You've rewritten a finite integral into an infinite sum (of the same function), but that's only one step.

    • @zzambezi1959
      @zzambezi1959 Місяць тому

      But the infinite sum is always defined as a limit, which is in this case a certain (finite) constant, I think.

  • @duckyoutube6318
    @duckyoutube6318 22 дні тому

    U sub is so useful.

  • @DJ_Kamenskuy
    @DJ_Kamenskuy Місяць тому

    Very interesting ! Thank you for your solution

  • @MeiziVu
    @MeiziVu Місяць тому +2

    Love uuuu ❤

  • @a4edits709
    @a4edits709 Місяць тому

    Hey newtons, I’m a 10 year old learning calculus, I know a lot (not like a whole college course) I’ve started Calculus 3, So I need help and my exams are there too. everything’s to me is easy. I started in February of my advanced mathematics learning when I was 9.

  • @dronevluchten
    @dronevluchten Місяць тому

    I agree with @misteribel that you replaced one riddle with another one. And solving that one, gives the first again. The only thing (okay, a great find) you showed is that some finite integral of x to the power -x can be replaced by an infinite sum of more or less the same function.
    What I missed in this video is what in fact is the meaning or consequence of this result.

    • @sovietwizard1620
      @sovietwizard1620 Місяць тому

      It's the non-closed form solution for the definite integral thats much easier to evaluate than the integral by itself.

  • @Tomorrow32
    @Tomorrow32 Місяць тому

    I love Math.
    Think you, sir.

  • @oniondeluxe9942
    @oniondeluxe9942 21 день тому

    Could you do a more elaborate video on when you can swap an integral and a sum, and when you cannot? Preferably with some examples.

  • @CharlesAbernathy-u6r
    @CharlesAbernathy-u6r 23 дні тому +1

    Can you teach a full course on calculus from beginning through Cal III?

    • @PrimeNewtons
      @PrimeNewtons  23 дні тому

      That is my new goal. I'm working on it

  • @johannkarrer2823
    @johannkarrer2823 Місяць тому +1

    Chapeau 👌🙏👍

  • @INFERNO_GAMER1
    @INFERNO_GAMER1 Місяць тому +1

    Beautiful

  • @anonpro
    @anonpro Місяць тому +1

    I found that you could derive a quick formula for any integral ₀∫¹ rx^(tx) dx === (k=1 to ∞)Σ (r*(-t)^(k-1))/(k^k), where r and t are any real number.
    For example, if you plug in 1 for r and -1 for t, the series will simplify to the final answer at the end of this video. Because that will create the problem that is presented and answered in this video ₀∫¹ 1x^(-1x) dx :)

  • @alltronics1337
    @alltronics1337 Місяць тому +1

    19:10 Isn’t the integral equal to (n-1)!, because it is gamma(n). But previously you established gamma(n+1) as equal to n! and not (n+1)!

    • @justcommenting5117
      @justcommenting5117 Місяць тому +1

      I was wondering the same thing

    • @asparkdeity8717
      @asparkdeity8717 Місяць тому +3

      No, the integral is n! since:
      Γ(z) = (z-1)! = ∫[0 to ∞] t^(z-1) e^(-t)dt
      i.e. Γ(z+1) = z! = = ∫[0 to ∞] t^z e^(-t)dt
      The power of the integrand is itself shifted in the definition of the Γ function

  • @robblerouser5657
    @robblerouser5657 23 дні тому

    Am I a geek for liking these calculus videos?

    • @aalekhjain2682
      @aalekhjain2682 22 дні тому

      You are not alone bud, I don't even get most of it.

  • @MadaraUchihaSecondRikudo
    @MadaraUchihaSecondRikudo Місяць тому +5

    This is a really surprising result. The "super sum" of 1/x^x from 0 to 1 is equal to the rest of the normal sum from 1 to infinity, fascinating! Do you have any idea why this pattern appears?

    • @xinpingdonohoe3978
      @xinpingdonohoe3978 Місяць тому

      I'm not sure, but there's an even better result.
      The "super sum" of nCr(α,x) dx from -∞ to ∞ is equal to the normal sum of nCr(α,x) from -∞ to ∞.

    • @alphazero339
      @alphazero339 Місяць тому

      Premium sum of 0 is same like normal sum of 0💀

  • @ahalfemptycup
    @ahalfemptycup 21 день тому

    Nice work 👍.
    I think you made a mostake though. At the end, you obtained the zeta function of n which is equal to (n-1)! Not n!.
    Edit: the gamma function of n

    • @Grecks75
      @Grecks75 6 днів тому

      No, no mistake. The value of the Euler integral used in the video is in fact Γ(n+1) which is equal to n!.

    • @ahalfemptycup
      @ahalfemptycup 6 днів тому

      @@Grecks75 oh shoot, you're right. It happened, I started to forget basic math knowledge from school. Never thought it could be the gamma function tho

  • @boranxiii
    @boranxiii Місяць тому

    well if you replace x with -x you just have sophomore's dream 🤷‍♀️

  • @royprasad
    @royprasad 29 днів тому

    Wow. My compliments!

  • @user-ke9lz8bt1c
    @user-ke9lz8bt1c 27 днів тому

    Sir , can we indefinitely integrate the function x^-x once as the form of a^x and once in the form of x^n and sum those 2 up and plug in the limits { for 0 (the limit) we could just substitute α and make α tend to 0}

  • @hasansawaf8616
    @hasansawaf8616 22 дні тому

    love it ❤

  • @82rah
    @82rah Місяць тому +1

    Wow! Great job.

  • @krit05007
    @krit05007 27 днів тому

    LOVE YOU DUDE

  • @tioulioulatv9332
    @tioulioulatv9332 9 днів тому

    دائما براهينكم رائعة

  • @aljawad
    @aljawad Місяць тому

    That was a juicy one! ❤

  • @Calcprof
    @Calcprof Місяць тому

    I've seen this attributed to John Bernoulli

  • @blasdelezo8396
    @blasdelezo8396 Місяць тому

    Beatiful

  • @goldenhowlxd9554
    @goldenhowlxd9554 20 днів тому

    What a question wow

  • @surankande8296
    @surankande8296 День тому

    so did the integral just convert to a more "discrete" form like earlier it was integral of all x^(-x) from 0 to 1 and in the end we are summing all k^(-k) for each natural k ... on the left we see is some summation of uncountable number of points but on the right its just some countable number of points .. am i missing something please help .. thank you

  • @mohsenrezaei5965
    @mohsenrezaei5965 3 дні тому

    you miss a minus: right side of the board,third line: minus e to the minus t. am I right?

  • @bobajaj4224
    @bobajaj4224 28 днів тому

    will this hold if 'a' is a complex number?😉

  • @JoaoHenrique-fs9ty
    @JoaoHenrique-fs9ty Місяць тому

    👏👏👏👏

  • @siraj_a.r.411
    @siraj_a.r.411 15 днів тому

    I have one doubt here, how did you write (-1)^n as 1? Shouldn't it be kept as (-1)^n only in the final answer?

  • @Mangogh-cx-9
    @Mangogh-cx-9 24 дні тому

    ❤❤

  • @singlovehk0518
    @singlovehk0518 Місяць тому

    hello, is the final solution just a Riemann sum version of the integral? The last line looks like some high school questions on the limit of some summations, which those questions require kids to transform the sum into the integral to get the final answer. Thanks!

  • @gustavoromero2050
    @gustavoromero2050 25 днів тому +1

    Hermoso problema

  • @Terrible_musculature
    @Terrible_musculature Місяць тому

    Is it me or we can reach the result in one lign with riemann sum ?

  • @thaerthaer1120
    @thaerthaer1120 Місяць тому

    Perfect

  • @sandem4592
    @sandem4592 Місяць тому

    Could you please attempt x^(1/x) from 0 to 1? I've managed to create a series for the general case of x^x^s when s >= 0. I could share my derivation if you (or anyone else) is interested.

  • @ManojkantSamal
    @ManojkantSamal 17 днів тому

    Respected Sir, Good morning.... Pls get me the solution of integration {1/(x^6+1)}, 0 to 3

  • @matthewware8973
    @matthewware8973 Місяць тому

    Bravo

  • @MAHDIALI-uh9fq
    @MAHDIALI-uh9fq Місяць тому

    you can't add more calculations??

  • @naygoats955
    @naygoats955 13 днів тому

    No way I got this right 😂

  • @pechenka2192
    @pechenka2192 8 днів тому

    В России такое решит любой 11 классик…

  • @thaerthaer1120
    @thaerthaer1120 Місяць тому

    Also there was one integration I still remember from Calc 2 or one if u can solve its integration of 1/(1+tan^4(×))

  • @ahmettasdemir59
    @ahmettasdemir59 22 дні тому

    bad light system

  • @whaddoiknow6519
    @whaddoiknow6519 10 днів тому

    I regret to say I am not impressed, just as I am not impressed with so many of the make-work problems on the MIT integration Bee. The final sum is just as intractable as the original integral, so one has made no progress at all. Much better would be to go back to G. H. Hardy's classic Pure Mathematics and master the 10 or so pages in the section entitled On the Practical Problem of Integration.

  • @saqarislam6350
    @saqarislam6350 Місяць тому

    The text is covering your writing and you can’t follow what you are doing ! Why you need the text ?

    • @PrimeNewtons
      @PrimeNewtons  Місяць тому

      I am not aware of any text. Check your settings. You may have cc turned on.

  • @bahadrdogrusoz3796
    @bahadrdogrusoz3796 3 години тому

    I couldn't understand. There was no good explanation.

  • @halid9457
    @halid9457 Місяць тому

    Whats your intro music?

    • @PrimeNewtons
      @PrimeNewtons  Місяць тому +3

      It's the prime Newton's signature music. I went to the studio myself.

  • @Billts
    @Billts 25 днів тому

    Αυτά είναι πανεπιστήμιο.εγω δε τα ξέρω λύκειο ειμαι😢

  • @anshkadamyt5268
    @anshkadamyt5268 Місяць тому

    !!!!!!!!!!

  • @viking_NO
    @viking_NO Місяць тому

    😇

  • @amritpatel3794
    @amritpatel3794 7 днів тому

    Excellent !!!

  • @Misteribel
    @Misteribel Місяць тому +4

    1.29128599706... (I'm gonna assume there's no exact solution)

    • @asparkdeity8717
      @asparkdeity8717 Місяць тому +1

      I think a beautiful power series is exact enough

  • @comdo777
    @comdo777 Місяць тому +2

    asnwer=1xy isit