Integrate x^-x dx

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  • เผยแพร่เมื่อ 8 ก.ย. 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.

ความคิดเห็น • 132

  • @jmmc6219
    @jmmc6219 หลายเดือนก่อน +152

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

    • @dannysigurdson7108
      @dannysigurdson7108 21 วันที่ผ่านมา

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

  • @Modo942000
    @Modo942000 หลายเดือนก่อน +90

    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 24 วันที่ผ่านมา +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 วันที่ผ่านมา +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 หลายเดือนก่อน +80

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

    • @kevinbush4300
      @kevinbush4300 หลายเดือนก่อน +1

      Yes, it's very reassuring

    • @user-iw8dj6yw9y
      @user-iw8dj6yw9y หลายเดือนก่อน

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

    • @sovietwizard1620
      @sovietwizard1620 หลายเดือนก่อน +2

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

    • @tessfra7695
      @tessfra7695 หลายเดือนก่อน +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 29 วันที่ผ่านมา +14

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

    • @ranae6566
      @ranae6566 26 วันที่ผ่านมา +2

      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 วันที่ผ่านมา

      @@ranae6566 learning means not only studies..

  • @BartBuzz
    @BartBuzz หลายเดือนก่อน +22

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

    • @PrimeNewtons
      @PrimeNewtons  หลายเดือนก่อน +28

      1.29129

    • @BartBuzz
      @BartBuzz หลายเดือนก่อน +20

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

    • @geertfdevries9518
      @geertfdevries9518 27 วันที่ผ่านมา +1

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

    • @ahalfemptycup
      @ahalfemptycup 20 วันที่ผ่านมา

      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 วันที่ผ่านมา +1

      @@BartBuzz Same here..i am 70.

  • @stevebeal73
    @stevebeal73 หลายเดือนก่อน +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 หลายเดือนก่อน +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.

  • @davidtallent8161
    @davidtallent8161 25 วันที่ผ่านมา +5

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

  • @asparkdeity8717
    @asparkdeity8717 หลายเดือนก่อน +13

    It really feels like a Sophomore’s Dream!

  • @smftrsddvjiou6443
    @smftrsddvjiou6443 หลายเดือนก่อน +17

    Wow, did not expect that is so complicated.

  • @eng954
    @eng954 16 วันที่ผ่านมา +2

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

  • @renesperb
    @renesperb หลายเดือนก่อน +8

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

  • @arantheo8607
    @arantheo8607 หลายเดือนก่อน +3

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

  • @dangernuke929
    @dangernuke929 หลายเดือนก่อน +15

    That was spectacular! Beautifully done!

  • @VenkateshSundararajan-tr6ve
    @VenkateshSundararajan-tr6ve 27 วันที่ผ่านมา +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”😅😅😅

  • @zealous2835
    @zealous2835 หลายเดือนก่อน +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

  • @peterpeter4134
    @peterpeter4134 หลายเดือนก่อน +4

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

    • @PrimeNewtons
      @PrimeNewtons  หลายเดือนก่อน +3

      Haha. That's hard to prove.

  • @alt_account4866
    @alt_account4866 26 วันที่ผ่านมา +3

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

  • @tanelkagan
    @tanelkagan 18 วันที่ผ่านมา +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 วันที่ผ่านมา +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.

  • @malayrojak
    @malayrojak 17 วันที่ผ่านมา +1

    Well the ending was a Revelation! Thanks for sharing!

  • @Jeremy-i1d
    @Jeremy-i1d 25 วันที่ผ่านมา +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 ❤

  • @Al-Shorman
    @Al-Shorman หลายเดือนก่อน +14

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

  • @tangential-research-ql5yd
    @tangential-research-ql5yd 14 วันที่ผ่านมา

    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!

  • @kquat7899
    @kquat7899 21 วันที่ผ่านมา +1

    Sloane's constant ~ 1.29...

  • @THESHAURYASHUKLA
    @THESHAURYASHUKLA 23 วันที่ผ่านมา +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 21 วันที่ผ่านมา

      JEE Advanced doesn't ask this level of calculus imo

    • @THESHAURYASHUKLA
      @THESHAURYASHUKLA 15 วันที่ผ่านมา

      @@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 14 วันที่ผ่านมา

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

  • @marasw
    @marasw 21 วันที่ผ่านมา +1

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

  • @epsilonxyzt
    @epsilonxyzt หลายเดือนก่อน +1

    Never Stop Teaching!

  • @AndrejPanjkov
    @AndrejPanjkov 23 วันที่ผ่านมา +1

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

  • @MinhNguyen-ij5md
    @MinhNguyen-ij5md 5 วันที่ผ่านมา +1

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

  • @markorletsky5976
    @markorletsky5976 21 วันที่ผ่านมา +1

    That made my Sunday evening pleasant.

  • @joefreiburg2716
    @joefreiburg2716 21 วันที่ผ่านมา

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

  • @ManojkantSamal
    @ManojkantSamal 17 วันที่ผ่านมา

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

  • @sammtanX
    @sammtanX หลายเดือนก่อน +3

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

  • @johnplong3644
    @johnplong3644 หลายเดือนก่อน

    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 .

  • @ultrasteamcarpetcleaning3207
    @ultrasteamcarpetcleaning3207 หลายเดือนก่อน

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

  • @kallek9645
    @kallek9645 25 วันที่ผ่านมา

    Top quality! Grateful for this teaching!

  • @user-eb5dt9ln9g
    @user-eb5dt9ln9g 22 ชั่วโมงที่ผ่านมา +1

    God this is epic

  • @a4edits709
    @a4edits709 หลายเดือนก่อน

    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.

  • @Toldasor
    @Toldasor 28 วันที่ผ่านมา

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

    • @geertfdevries9518
      @geertfdevries9518 27 วันที่ผ่านมา +1

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

  • @dronevluchten
    @dronevluchten หลายเดือนก่อน

    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 หลายเดือนก่อน

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

  • @user-yg2yi6gy3c
    @user-yg2yi6gy3c หลายเดือนก่อน +1

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

  • @johanneshagel3609
    @johanneshagel3609 24 วันที่ผ่านมา

    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 หลายเดือนก่อน +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 หลายเดือนก่อน

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

  • @Naomi_stephy
    @Naomi_stephy หลายเดือนก่อน

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

  • @oniondeluxe9942
    @oniondeluxe9942 20 วันที่ผ่านมา

    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.

  • @duckyoutube6318
    @duckyoutube6318 21 วันที่ผ่านมา

    U sub is so useful.

  • @DJ_Kamenskuy
    @DJ_Kamenskuy หลายเดือนก่อน

    Very interesting ! Thank you for your solution

  • @Tomorrow32
    @Tomorrow32 หลายเดือนก่อน

    I love Math.
    Think you, sir.

  • @MeiziVu
    @MeiziVu หลายเดือนก่อน +2

    Love uuuu ❤

    • @PrimeNewtons
      @PrimeNewtons  หลายเดือนก่อน

      Love uuuu tuuu

  • @royprasad
    @royprasad 28 วันที่ผ่านมา

    Wow. My compliments!

  • @INFERNO_GAMER1
    @INFERNO_GAMER1 หลายเดือนก่อน +1

    Beautiful

  • @CharlesAbernathy-u6r
    @CharlesAbernathy-u6r 23 วันที่ผ่านมา +1

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

    • @PrimeNewtons
      @PrimeNewtons  23 วันที่ผ่านมา

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

  • @user-ke9lz8bt1c
    @user-ke9lz8bt1c 27 วันที่ผ่านมา

    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}

  • @anonpro
    @anonpro หลายเดือนก่อน +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 :)

  • @hasansawaf8616
    @hasansawaf8616 21 วันที่ผ่านมา

    love it ❤

  • @alltronics1337
    @alltronics1337 หลายเดือนก่อน +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 หลายเดือนก่อน +1

      I was wondering the same thing

    • @asparkdeity8717
      @asparkdeity8717 หลายเดือนก่อน +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

  • @82rah
    @82rah หลายเดือนก่อน +1

    Wow! Great job.

  • @johannkarrer2823
    @johannkarrer2823 หลายเดือนก่อน +1

    Chapeau 👌🙏👍

  • @MadaraUchihaSecondRikudo
    @MadaraUchihaSecondRikudo หลายเดือนก่อน +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 หลายเดือนก่อน

      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 หลายเดือนก่อน

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

  • @surankande8296
    @surankande8296 18 ชั่วโมงที่ผ่านมา

    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

  • @ahalfemptycup
    @ahalfemptycup 20 วันที่ผ่านมา

    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 วันที่ผ่านมา

      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 วันที่ผ่านมา

      @@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

  • @Calcprof
    @Calcprof หลายเดือนก่อน

    I've seen this attributed to John Bernoulli

  • @boranxiii
    @boranxiii หลายเดือนก่อน

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

  • @robblerouser5657
    @robblerouser5657 23 วันที่ผ่านมา

    Am I a geek for liking these calculus videos?

    • @aalekhjain2682
      @aalekhjain2682 21 วันที่ผ่านมา

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

  • @siraj_a.r.411
    @siraj_a.r.411 15 วันที่ผ่านมา

    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?

  • @singlovehk0518
    @singlovehk0518 หลายเดือนก่อน

    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!

  • @blasdelezo8396
    @blasdelezo8396 หลายเดือนก่อน

    Beatiful

  • @sandem4592
    @sandem4592 หลายเดือนก่อน

    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.

  • @aljawad
    @aljawad หลายเดือนก่อน

    That was a juicy one! ❤

  • @krit05007
    @krit05007 26 วันที่ผ่านมา

    LOVE YOU DUDE

  • @goldenhowlxd9554
    @goldenhowlxd9554 20 วันที่ผ่านมา

    What a question wow

  • @mohsenrezaei5965
    @mohsenrezaei5965 3 วันที่ผ่านมา

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

  • @tioulioulatv9332
    @tioulioulatv9332 8 วันที่ผ่านมา

    دائما براهينكم رائعة

  • @thaerthaer1120
    @thaerthaer1120 หลายเดือนก่อน

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

  • @bobajaj4224
    @bobajaj4224 27 วันที่ผ่านมา

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

  • @thaerthaer1120
    @thaerthaer1120 หลายเดือนก่อน

    Perfect

  • @ManojkantSamal
    @ManojkantSamal 17 วันที่ผ่านมา

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

  • @gustavoromero2050
    @gustavoromero2050 25 วันที่ผ่านมา +1

    Hermoso problema

  • @whaddoiknow6519
    @whaddoiknow6519 10 วันที่ผ่านมา

    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.

  • @Terrible_musculature
    @Terrible_musculature หลายเดือนก่อน

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

  • @matthewware8973
    @matthewware8973 หลายเดือนก่อน

    Bravo

  • @naygoats955
    @naygoats955 13 วันที่ผ่านมา

    No way I got this right 😂

  • @Mangogh-cx-9
    @Mangogh-cx-9 23 วันที่ผ่านมา

    ❤❤

  • @JoaoHenrique-fs9ty
    @JoaoHenrique-fs9ty หลายเดือนก่อน

    👏👏👏👏

  • @pechenka2192
    @pechenka2192 8 วันที่ผ่านมา

    В России такое решит любой 11 классик…

  • @MAHDIALI-uh9fq
    @MAHDIALI-uh9fq หลายเดือนก่อน

    you can't add more calculations??

  • @saqarislam6350
    @saqarislam6350 หลายเดือนก่อน

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

    • @PrimeNewtons
      @PrimeNewtons  หลายเดือนก่อน

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

  • @ahmettasdemir59
    @ahmettasdemir59 22 วันที่ผ่านมา

    bad light system

  • @halid9457
    @halid9457 หลายเดือนก่อน

    Whats your intro music?

    • @PrimeNewtons
      @PrimeNewtons  หลายเดือนก่อน +3

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

  • @Billts
    @Billts 25 วันที่ผ่านมา

    Αυτά είναι πανεπιστήμιο.εγω δε τα ξέρω λύκειο ειμαι😢

  • @anshkadamyt5268
    @anshkadamyt5268 หลายเดือนก่อน

    !!!!!!!!!!

  • @viking_NO
    @viking_NO หลายเดือนก่อน

    😇

  • @amritpatel3794
    @amritpatel3794 7 วันที่ผ่านมา

    Excellent !!!

  • @Misteribel
    @Misteribel หลายเดือนก่อน +4

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

    • @asparkdeity8717
      @asparkdeity8717 หลายเดือนก่อน +1

      I think a beautiful power series is exact enough

  • @comdo777
    @comdo777 หลายเดือนก่อน +2

    asnwer=1xy isit