The Integral of your Dreams (or Nightmares)

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BriTheMathGuy

BriTheMathGuy

Күн бұрын

Пікірлер: 521
@BriTheMathGuy
@BriTheMathGuy Жыл бұрын
🎓Become a Math Master With My Intro To Proofs Course! (FREE ON KZbin) kzbin.info/www/bejne/aZTdmJl-irGNedU
@neiljf1089
@neiljf1089 3 жыл бұрын
At first I was amazed that he can do backwards writing so neatly. Then realised he just flipped the video
@HogTieChamp
@HogTieChamp 3 жыл бұрын
I was amazed but then you ruined the magic for me!!
@manasaprakash7125
@manasaprakash7125 3 жыл бұрын
What????
@offbeatstuff8473
@offbeatstuff8473 3 жыл бұрын
I was just going to comment the same thing.
@umershaikh7179
@umershaikh7179 2 жыл бұрын
that is pretty obvious...
@ParagPardhiNITT
@ParagPardhiNITT 2 жыл бұрын
@@manasaprakash7125 sarcasm dude 😅
@Ascientistsjourney
@Ascientistsjourney 3 жыл бұрын
Mathematicians: Look at my integral of my dreams. Physicists: Cool. But does that serve any purpose? Mathematicians: NO, but look at it. It's so magical. ;p
@123akash121
@123akash121 3 жыл бұрын
truest thing i have heard
@mathieuaurousseau100
@mathieuaurousseau100 3 жыл бұрын
Next century physicist : hey guys, you will never believe what weird function I'm trying to integrate today
@jimschneider799
@jimschneider799 3 жыл бұрын
@@mathieuaurousseau100 - this century's pure mathematics is next century's applied mathematics, because of those meddling physicists.
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
😂So True!
@Ascientistsjourney
@Ascientistsjourney 3 жыл бұрын
@@BriTheMathGuy woah you saw my comment. Thanks bro you made my day 😊
@az0rs
@az0rs 3 жыл бұрын
Holy cow that’s the prettiest integral I have ever seen
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
I think so too!
@mathe.dominio4765
@mathe.dominio4765 2 жыл бұрын
👌
@turbostar101
@turbostar101 2 жыл бұрын
And he’s doing it backwards!
@eduferreyraok
@eduferreyraok 2 жыл бұрын
I would took a little twist over the improper integral, by applying a laplace transform which matches with the definition : F(s) = L { f(t) } = integral from 0 to inf of f(t). e^(-st) dt .
@tnk4me4
@tnk4me4 3 жыл бұрын
Never have I understood "Sufficiently advanced math is indistinguishable from magic" more than this very moment.
@GreenCaulerpa
@GreenCaulerpa 3 жыл бұрын
Except the original quote was “Any sufficiently advanced technology is indistinguishable from magic” from Arthur C. Clarke‘s book „Profiles of the Future: An Inquiry into the Limits of the Possible“ (1962). But I agree this integral is pretty much nightmare stuff if you haven‘t seen once how to solve it.
@tnk4me4
@tnk4me4 3 жыл бұрын
@@GreenCaulerpa Yes thank you for explaining the joke. You get an internet cookie. Congratulations.
@GreenCaulerpa
@GreenCaulerpa 3 жыл бұрын
@@tnk4me4 yummy, thanks for that cookie!
@rmxevbio5889
@rmxevbio5889 2 жыл бұрын
@@GreenCaulerpa nice quote!
@mrnogot4251
@mrnogot4251 3 жыл бұрын
2:40 dude nice thank you for being aware that you can’t just interchange infinite sums and integrals willy nilly.
@HeinrichHartmann
@HeinrichHartmann 3 жыл бұрын
He did not give an argument, though. He just mentioned "uniform convergence". But why would this sum converge uniformly? ln(x) has a singularity at 0, so I am not sure about uniform convergance on [0,1].
@grekiki
@grekiki 3 жыл бұрын
@@HeinrichHartmann Series for e^x converges absolutely
@markusdemedeiros8513
@markusdemedeiros8513 3 жыл бұрын
​@@HeinrichHartmann I can try to fill in the details for anyone interested: x log(x) is bounded on (0,1]: I will not do this here but it is concave up, has a minimum, and the limit at both 0 and 1 is 0. Therefore there's some closed interval containing all values of x log x for x in (0,1]. The power series of e^x converges uniformly on any closed subinterval of it's interval of convergence R, so the series for e^(x log x) converges uniformly for x in (0,1].
@holomurphy22
@holomurphy22 3 жыл бұрын
@@markusdemedeiros8513 One could just say that x log(x) is continuous on (0,1] and can be extended continuously to [0,1] as it converges to 0 in 0. The extended function is bounded because of 'extreme value theorem' and thus x log(x) is bounded on (0,1] I may be misspelling things a bit
@onradioactivewaves
@onradioactivewaves 3 жыл бұрын
@@markusdemedeiros8513 thanks, I appreciate that summary.
@tommassspunis8184
@tommassspunis8184 3 жыл бұрын
Damn i got stuck watching this video and the integral of e^-x^2 in loop because at the end of each video the guy says “click on the video on the screen” and its an infinite loop :D
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
You've fallen into my trap!!
@Muhahahahaz
@Muhahahahaz 7 ай бұрын
Oh no… I actually just arrived at this video from a different video, but I could end up in the same loop as well Next step: make sure that every sequence of video links eventually leads to this specific loop. Reminds me of the Collatz Conjecture… 🤔
@nikned27th74
@nikned27th74 3 жыл бұрын
Nice result, but now you should explain what is the value of the infinite sum 🛡️
@johannes8144
@johannes8144 3 жыл бұрын
It's maybe a bit late, but the value is round about 1.2912859970626636
@zebran4
@zebran4 3 жыл бұрын
@@johannes8144 Thank you! Did you compute that analyticaly or numericaly?
@polychromaa
@polychromaa 2 жыл бұрын
@@zebran4 It’s not possible to compute the value analytically as of this moment.
@user_2793
@user_2793 2 жыл бұрын
@@zebran4 By analytically you mean in terms of "non trivial" functions/expressions? If so it's very unlikely this can be expressed like that, just as a gut feeling
@zebran4
@zebran4 2 жыл бұрын
@@user_2793 Yes. By trivial expresions too.
@Roboboy-v6
@Roboboy-v6 3 жыл бұрын
As an engineering student my first instinct was to use a euler's method of approximation cause "fuck that work" LOL
@adamuhaddadi5332
@adamuhaddadi5332 3 жыл бұрын
stupid approximateurs >:(
@bowenjudd1028
@bowenjudd1028 3 жыл бұрын
It’s ancient, but it works
@chungus478
@chungus478 3 жыл бұрын
You know you're an engineer when using π=3 does not seem like an approximation
@bowenjudd1028
@bowenjudd1028 3 жыл бұрын
@@chungus478, and a mathematics or physics student if it does.
@ilyaxi
@ilyaxi 3 жыл бұрын
What's most fascinating is the way he looks to be writing from right to left for us. It's surely inverted but stil.. Thanks for the vid
@cnvrgnt
@cnvrgnt 3 жыл бұрын
That was NOT the result I was expecting form this. Absolutely beautiful
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Glad you enjoyed it!
@kaasmeester5903
@kaasmeester5903 2 жыл бұрын
It is. But I still hate integrals :) I never had much issues with other mathematics (up to a masters in EE) but integrals always turn into these crappy little puzzles that apparently I'm just to dumb to solve.
@Francesco-bf8cb
@Francesco-bf8cb 3 жыл бұрын
I'm here to comment just to make your video more popular
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Thanks so much!
@FernandoRuiz-rf1om
@FernandoRuiz-rf1om 3 жыл бұрын
Does the final infinite sum converge? Awesome integral btw!
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Thanks! and yes it most certainly does! (around 1.29 or so)
@sophiophile
@sophiophile 3 жыл бұрын
@@BriTheMathGuy is there an exact identity for what it converges to, or did you just get this by approximation?
@leofisher1280
@leofisher1280 3 жыл бұрын
@@sophiophile there is no closed form for it sadly so all you can do is solve it numerically.
@davidgillies620
@davidgillies620 3 жыл бұрын
The good news is the convergence is extremely rapid. The first ten terms of the sum give you the value of the integral to about 3 parts in a trillion.
@olbluelips
@olbluelips 2 жыл бұрын
@@tBagley43 almost all this kind of stuff has no closed form
@sourabhparadeshi4162
@sourabhparadeshi4162 3 жыл бұрын
I have my term exams in few days and watching this is satisfying ❤️
@tamazimuqeria6496
@tamazimuqeria6496 3 жыл бұрын
Same here, good luck
@sourabhparadeshi4162
@sourabhparadeshi4162 3 жыл бұрын
@@tamazimuqeria6496 good luck
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Best of luck all!!
@heh2393
@heh2393 3 жыл бұрын
How was it?
@lucidmath5481
@lucidmath5481 2 жыл бұрын
we need more integrals like this, this is amazing
@EpicMathTime
@EpicMathTime 3 жыл бұрын
0:17 Well, we don't _have_ to. The power rule gives xx^(x-1) = x^x, the exponential rule gives ln(x)x^x, so the total derivative is the sum: x^x + ln(x)x^x.
@qq3088
@qq3088 3 жыл бұрын
That works for x^x and x^(-x). But does this work for any derivative of f(x)^f(x)? Or only those cases?
@EpicMathTime
@EpicMathTime 3 жыл бұрын
@@qq3088 It generally works. It doesn't have to be exponentiation, and the functions don't need to be the same. It's a general property of differentiation that is used extensively. In other words, every derivative of a function with multiple instances of x can be realized as the sum of all "partial derivatives" with respect to each instance of x.
@qq3088
@qq3088 3 жыл бұрын
@@EpicMathTime l never knew this!
@dawnstudios7813
@dawnstudios7813 3 жыл бұрын
@@EpicMathTime "every derivative of a function with multiple instances of x can be realized as the sum of all partial derivatives with respect to each instance of x", damn that looks like a powerful statement. Do you know a proof for this?
@EpicMathTime
@EpicMathTime 3 жыл бұрын
@@dawnstudios7813 The simplest way to see this is to replace each instance of x with a separate variable (say x, y, etc), and take the total derivative with respect to t. Then, set x = y = ... = t. This collapses the total derivative to the special case of the single variable derivative. This idea underpins differentiation very intimately. You're already doing it when you take any derivative, we just don't phrase it that way. For example, let's take the derivative of sin(x)cos(x) using the statement you just quoted. I'll treat the first instance of x as a constant, making sin(x) a "coefficient", so that 'partial derivative' is -sin(x)². Now I'll treat the second instance of x as constant, and likewise, that 'partial derivative' is cos(x)². Hence, the derivative is the sum of the "partials": cos(x)² - sin(x)². Although I phrased it in this different way, what we did there is precisely the product rule. In other words, the product rule itself is a specific instance of doing the quoted statement.
@paolomeola6180
@paolomeola6180 3 жыл бұрын
Just do the transform y = -x and then you solve in dy! we already know the answer!
@seemagupta1467
@seemagupta1467 3 жыл бұрын
I have a question Isn't the final summation converged to something like π/ ( something) ?
@alexanderkartun-giles5961
@alexanderkartun-giles5961 3 жыл бұрын
The sum equals exactly 1.29129
@casual0815
@casual0815 3 жыл бұрын
I think you might me referring to a similar sum: n goes from 0 to infinity, 1/n^2 The sum is equal to pi^2/6.
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Integrals Playlist! kzbin.info/www/bejne/oGGtf2OnbauIqrs
@onradioactivewaves
@onradioactivewaves 3 жыл бұрын
It took 3 minutes for you to get to U substitution where I finally stopped questiining my sanity.
@uyeuejiwgiuyeuejiwgi5725
@uyeuejiwgiuyeuejiwgi5725 2 жыл бұрын
10/2 = {2,2,2,2,2} != 5
@motherisape
@motherisape 2 жыл бұрын
It's 1.29128
@adb012
@adb012 3 жыл бұрын
Something that surprised me more than the continuous sum being equal to the discrete sum is the bounds of those sums. The continuous sum of x^(-x) from 0 to 1 equals the discrete sum of n^(-n) from 1 to infinity... *SAY WHAT?!?!?*
@asdfgmnbvczxcv
@asdfgmnbvczxcv 3 жыл бұрын
IT'S CONVERGENT!!!!
@jackweslycamacho8982
@jackweslycamacho8982 3 жыл бұрын
It's even crazier how fast it converges. For the first 7 values of n you literally have n digits of precision, after that it the rate of precision keeps getting higher.
@captainhd9741
@captainhd9741 3 жыл бұрын
Care to share an example? I am admittedly too lazy to figure out the value of the sum and how fast it gets to these values.
@jackweslycamacho8982
@jackweslycamacho8982 3 жыл бұрын
@@captainhd9741 use desmos and input sum for sum and int for integral
@captainhd9741
@captainhd9741 3 жыл бұрын
@@jackweslycamacho8982 I prefer Wolfram but good idea!
@MarioRossi-sh4uk
@MarioRossi-sh4uk 3 жыл бұрын
@@captainhd9741 1 1 2 1.25 3 1.28703703703704 4 1.29094328703704 5 1.29126328703704 6 1.29128472050754 7 1.29128593477322 8 1.29128599437787 9 1.29128599695904 10 1.29128599705904 11 1.29128599706255 12 1.29128599706266 13 1.29128599706266
@miguelcerna7406
@miguelcerna7406 2 жыл бұрын
I find this so pretty. Almost like discrete sum (over all integers) of sinx/x = pi and integral (-inf to +inf) of sinx/x also equals pi. Amazing and yet baffling.
@God-ld6ll
@God-ld6ll 3 жыл бұрын
maybe more like a sophomore's nightmare to some i'd imagine
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
😂
@abhaysharma3467
@abhaysharma3467 3 жыл бұрын
i'm in class 12 but i can understand this😍
@Deus_Auto
@Deus_Auto 3 жыл бұрын
It's ≈ 1.291291≈ 430/333
@joshuaisemperor
@joshuaisemperor 3 жыл бұрын
blew my mind. Never seen summation and integrals after each other.
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Pretty cool right?
@joshuaisemperor
@joshuaisemperor 3 жыл бұрын
@@BriTheMathGuy yeah but it also feels intimidating for someone who still has to pass his Calc 2.
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
You can do it though!
@lukekolodziej9631
@lukekolodziej9631 3 жыл бұрын
I honestly think I'm more impressed by how good you are at writing backwards. LOL! Good video
@destructiveodst1199
@destructiveodst1199 3 жыл бұрын
He’s not writing backwards it’s just mirrored lol
@Unifrog_
@Unifrog_ 3 жыл бұрын
I'm impressed by how well he can write mirrored then /jk
@FatihKarakurt
@FatihKarakurt 3 жыл бұрын
Glass pane works really well. If you can dim the lights over your hand it will be much better.
@carljohanr
@carljohanr 3 жыл бұрын
Really nice results - I assume there is no closed form for the sum, but it made me a bit surprised at the end that you never touched on that topic.
@assasin1992m
@assasin1992m 3 жыл бұрын
There is, it equals sin(pi) / gamma(pi/2)
@captainhd9741
@captainhd9741 3 жыл бұрын
@@assasin1992m What is sine doing here? 🤔
@captainhd9741
@captainhd9741 3 жыл бұрын
@@assasin1992m makes me wonder if there is a complex extension for z^(-z) integral
@ha14mu
@ha14mu 3 жыл бұрын
Isn't sin(pi) 0?
@assasin1992m
@assasin1992m 3 жыл бұрын
@@ha14mu yes, but the limit toward pi in this expression converges to a non zero result
@Chrisuan
@Chrisuan 3 жыл бұрын
Love your content! You can really feel your love for the math
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Glad you enjoy it!
@suminhwang
@suminhwang 2 жыл бұрын
And i'm the only one who wanna know the way to use the backside screen?
@sebastienruhlmann3917
@sebastienruhlmann3917 2 жыл бұрын
The actually important explanation for interchanging sum and integral is brushed away like nothing. This took away the beauty of it.
@danieljulian4676
@danieljulian4676 3 жыл бұрын
I tried thinking about this in a different way. I began by viewing the original (improper) integral as something I will call L (i.e., limiting sum for the improper integral). I take log(L) and then move the log operation on the inside of the integration. I doubt this obeys all the rules for logarithmic operations on (improper?) integrals. So now I am integrating the function -x log(x) dx on the same upper and lower bounds and still calling this L. The indefinite integral of this is computed to be (x^2)/4 - (1/2)(x^2) log x. Evaluating this at the limits gives 1/4 (the limit for the second term can be evaluated at the lower bound using rules for indeterminate forms and evaluates to a limiting value of 0, there from the right. Anyway, the upshot is that L = 1/4 which makes the original integral e^(1/4) or approximately 1.28, which is close to the result from the derivation in the video, but not identical. Why is this even close? I know something I've done must be wrong, probably because the integration must invoke the complex log function in some way, at least at the lower bound of integration.
@thisisnotmyrealname628
@thisisnotmyrealname628 3 жыл бұрын
7:08 moment of satisfaction
@FingertipsOfTheNight
@FingertipsOfTheNight 3 жыл бұрын
I pressumed the result should have been a numerical value, right ?
@grinreaperoftrolls7528
@grinreaperoftrolls7528 3 жыл бұрын
I freakin love calculus. I thought this was gonna be really scary at first.
@engr.rimarc.liguan1795
@engr.rimarc.liguan1795 3 жыл бұрын
This was the cutest introduction of solution I have ever seen in addition to the handsomeness of the one who introduced it. 😅🤭 Bravo!
@astronomer5589
@astronomer5589 3 жыл бұрын
But this integral incomplete you did not finf the limit of sequence but thank u for ur explaining it's useful
@noone8253
@noone8253 3 жыл бұрын
Got a similar problem in a calc 2 exam, I was very confused and thought it was unsolvable, still processing how to get a numerical value for the solution, very nice video!
@marshian__mallow2624
@marshian__mallow2624 2 жыл бұрын
For an integral like that. You don’t get a numerical value
@SuperYoonHo
@SuperYoonHo 2 жыл бұрын
definatley not MORE sophoMORE's dream out there or is it?! haha that would make my day if i had the dream of me having a dream which of i was having a dreaming that i was dreaming in my dream and in that dream i was doing this intergral😵😵
@Mkvyas1
@Mkvyas1 2 жыл бұрын
Whole video like... Question. Which letter is next after letter A in alphabet ? Answer. Which letter is before C in alphabet ?
@MaximQuantum
@MaximQuantum 2 жыл бұрын
Nightmare, bc the solution can only be solved with an approximation 😔😔😔
@charlierodriguez1206
@charlierodriguez1206 3 жыл бұрын
How does the result... make sense? I may be lost when ganma function, but the summatory of n^(-n) isn't just number + number + ...? So the derivative will be... 0?
@rachit7645
@rachit7645 Жыл бұрын
Wolphram Alpha says the final sum is approximately: 1.2912859970626635404072825905956005414986193682745223173100024451369445387652344555588170411294297089849950709248154305484104874192848641975791635559479136964969741568780207997291779482730090256492305507209666381284670120536857459787030012778941292882535517702223833753193457492599677796483008495491110669649755010519757429116210970215616695328976892427890058093908147880940367993055895352006337161104650946386068088649986065310218534124791597373052710686824652246770336860469870234201965831431339687388172956893553685179852142066626416543806122456994096635604388523996938130448401015323385569895478992261465970681807533429122890910049951364103584723741679660994037428872280908239472403012423375069665874314768350298347009659693019807122059415474239188849548892043147840373896935928327449373018601817579524681909135596506205768427008907326547137233834847185623248044173423385652705113744822086069838116970644789631554803110868684680780701057034230000954776628299270222642661822130291609344850492556799951212817650810621807347685511270748919272166418829000073661836619726956875357964537813752368262924072016883803114377731170
@padmasangale8194
@padmasangale8194 Жыл бұрын
How he interchanged the summation and integral signs at 2:30 please someone help me😢(btw i am class 11th student and jee aspirant)
@PunmasterSTP
@PunmasterSTP 3 жыл бұрын
Wow, that was sum-thing else; thank you so much for sharing!
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Glad you enjoyed it!
@rdsmofficial
@rdsmofficial 3 жыл бұрын
I have no idea what is going on and im thinking of studying applied maths....
@robertmonroe9728
@robertmonroe9728 2 жыл бұрын
Try to integrate it to infinity. Integral converges. But this way will not work
@sjzara
@sjzara 3 жыл бұрын
What I don’t understand is how mathematicians make such amazingly leaps such as the various substitutions to get to the answer.
@braedenbertz1063
@braedenbertz1063 2 жыл бұрын
Its a lot of trial and error, looking at past results and seeing if there are parallels, and a lot of luck :)
@alperenerol1852
@alperenerol1852 3 жыл бұрын
I was gonna discretize the domain and calculate the area by numerical methods.
@bowenjudd1028
@bowenjudd1028 3 жыл бұрын
I actually lost all sense realizing how cruel sone equations can be.
@444haluk
@444haluk 3 жыл бұрын
Chill, dude it is from 0 to 1, monte carlo it and move on.
@sergiomanzetti1021
@sergiomanzetti1021 3 жыл бұрын
Are you writing in mirror-image, or reflecting the entire video afterwards?
@michelplockyn404
@michelplockyn404 2 жыл бұрын
Impossible to understand for a normal person !!!
@muratkaradag3703
@muratkaradag3703 3 жыл бұрын
well with a suitable fourier series, we could calculate that value exactly....
@HershO.
@HershO. 3 жыл бұрын
Dude I checked on wolfram alpha and the sum is = 1.29129. See this is so cool cuz 129 is repeated. I love this.
@Timmmmartin
@Timmmmartin 3 жыл бұрын
Equal to 430/333 if 129 were to repeat indefinitely.
@HershO.
@HershO. 3 жыл бұрын
@@Timmmmartin no dude this is its exact value, its not recurring. It's not particularly fascinating of a fact but its cool.
@Timmmmartin
@Timmmmartin 3 жыл бұрын
@@HershO. Do you have the wolfram link please?
@이름-x6s
@이름-x6s 2 жыл бұрын
I am a university student in Korea. I was always interested in math, and I happened to see your KZbin while I was looking for a related KZbin while preparing for a math test. I think there are a lot of fun and informative contents. I hope your KZbin will be better and I will continue to look for it often. Thank you!
@limagabriel7
@limagabriel7 2 жыл бұрын
do u guys learn calculus in high school in korea?
@이름-x6s
@이름-x6s 2 жыл бұрын
@@limagabriel7 Yes, I do learn, but for example, in the case of calculus that utilizes two or more variables, I learn properly in college.
@uggupuggu
@uggupuggu 2 жыл бұрын
Why are you named Apple Boss
@ExtremeAgent
@ExtremeAgent 3 жыл бұрын
I always felt (if not knew) that integration from 0 to 1 is sum from 1 to infinity
@ooflespoofle3691
@ooflespoofle3691 2 жыл бұрын
"He will never cancel the n!" *spits out cereal*
@pvshka
@pvshka 3 жыл бұрын
Friggin high school maths still giving me headache. Good job
@sauravrao234
@sauravrao234 9 ай бұрын
I think what is amazing is that the integral of x^x within the same limits gives the same summation but with a (-1)^n, hence having alternating plus and minsu. So the integral of this video outputs a greater value than integral of x^x within the same limits, which makes sense. Because x^-x is bigger than x^x in this interval of 0 to 1.
@xeerakazhar9023
@xeerakazhar9023 3 жыл бұрын
How do you write laterally invertedly by the left hand?
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Video editing :)
@muqeetsoheb6708
@muqeetsoheb6708 3 жыл бұрын
Its intresting how he uses just SMALL PART of BOARD to explain such complex problems whereas for our teacher need two full boards
@HaLKer5
@HaLKer5 2 жыл бұрын
Wow, this was much better than i expected! Truly beautiful!
@jonathangrey6354
@jonathangrey6354 3 жыл бұрын
“Antideriving” *confused mathematician noises*
@mastershooter64
@mastershooter64 3 жыл бұрын
damn that's fuckin sick dude!
@penta4568
@penta4568 3 жыл бұрын
As someone who has graduated with an Applied Mathematics degree, I probably should know what’s going on here😅 (I do but it’s still a headache, I made it out & enjoy the fact that this stuff doesn’t come up often irl)
@josephhobbs4680
@josephhobbs4680 6 ай бұрын
approximately 1.29
@rabeakhatun2819
@rabeakhatun2819 3 жыл бұрын
Just wow 🔥🔥🔥🔥
@worldnotworld
@worldnotworld 3 жыл бұрын
I think blackPenRedPen did this too. It's fascinating. Is there a general class of functions that look "the same" in this way, the continuous definite integral correlating with a discrete sum? Or is this a one-off? Anyone know?
@Pod_TM
@Pod_TM 10 ай бұрын
Happens a lot under a set of conditions, but anything that has a taylor developpent withh a general term that verify the hypothesis of the sum-integral swap theorem will give you similar results, also anything that can be writen as the limit of the sum of a u_n=q^n, for exemple 1/(1+e^t) is the infinite sum of the u_n=(-e^t)^n and in the end it gives you a beatiful result, i'll let you find out.
@sciencewithali4916
@sciencewithali4916 3 жыл бұрын
I am genuinely getting addicted to your videos !
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
Glad you like them!
@xxbananahanahxx3012
@xxbananahanahxx3012 3 жыл бұрын
I like your funny words, magic man.
@ThomasKundera
@ThomasKundera 2 жыл бұрын
I would be unable to do it by myself without guidance But the whole video was a beautiful journey where I was smiling at each new trick Just disappointed it didn't arrived to some usual function development
@mimzim7141
@mimzim7141 3 жыл бұрын
So what is the value??
@prajwalhg9395
@prajwalhg9395 4 ай бұрын
Figure it out
@manuelaidos
@manuelaidos Жыл бұрын
d/dx (x^(-x)) = (-x)*x^(-x-1) = -x^(-x) * (1 + ln(x)) Since the integrand x^(-x) * (1 + ln(x)) cannot be simplified further, we conclude that the integral of x^(-x) cannot be expressed in terms of elementary functions. However, the integral can be expressed in terms of a special function called the exponential integral: ∫ x^(-x) dx = Ei(-ln(x)) + C
@guestmode867
@guestmode867 Жыл бұрын
kzbin.info/www/bejne/onnMZmaHmteYfqM 3:18 Actually, from here: we can pull out (-1)^n/n! outside the integral and the remaining integral from 0 to 1: ∫(xlnx)^ndx becomes a variant of the gamma function: -(-1/(n+1))^(n+1) gamma(n+1) Gamma of n + 1 is also n! so the final result is: summation from 0 to ∞[ {(-1)^n/n!} * n! * -1 * (-1)^n+1 * (1/n+1)^n+1 ] n factorials cancel out and the exponents of 1 are added up: ...[(-1)^(2n + 2) * (1/n+1)^(n+1)] Since the exponent of -1 is always even as we are taking a discrete sum of whole numbers, it is always positive 1 so we can remove it. = summation from 0 to ∞ of (1/n+1)^(n+1) changing the bounds of the summation by +1 and subtracting 1 from the n terms we get: summation from 1 to ∞ of (1/n)^n Since 1/n = n^-1 Answer = summation from 1 to ∞ of n^(-n)
@MrMatthewliver
@MrMatthewliver 3 жыл бұрын
How about an improper integral of x^-x from 0 to infinity? It is convergent to about 1,9954559575..., but how to compute it in a more simple way than just programming a scientific calculator to numerically calculate the Riemann's integral (area under the curve)?
@marcremarc
@marcremarc 3 жыл бұрын
Being good in math is impressive but writing in reverse perfectly makes you more exceptional
@omarramadhan1652
@omarramadhan1652 3 жыл бұрын
He doesn't write in reverse...this happens when someone write on the glass window while you are on the other side of the window....just think about it!
@marcremarc
@marcremarc 3 жыл бұрын
@@omarramadhan1652 Nah he's just super good and he learned to write in reverse
@knvcsg1839
@knvcsg1839 3 жыл бұрын
That answer is beautiful.
@DrJens-pn5qk
@DrJens-pn5qk 3 жыл бұрын
Very nice. But what is the value of the final sum? Does it even converge?
@lobsterfork
@lobsterfork 3 жыл бұрын
1^-1 + 2^-2 + 3^-3 + 4^-4 + 5^-5 + 6^-6 = 1.29128472051. I think more terms are necessary, for precisions sake, but you get the main idea.
@ranSmsB
@ranSmsB 2 жыл бұрын
To me, this result tells that there's the same amount of infinite possibilities between 0 and 1 as it is between 1 and infinity.
@kikones34
@kikones34 Жыл бұрын
It's tempting to reach that conclusion but it's incorrect, the set of real numbers from 0 to 1 has cardinality aleph_1, which is strictly greater than the set of natural numbers, which has cardinality aleph_0. In other words, if you would try to map each natural number into the set of real numbers from 0 to 1, you'd run out of natural numbers before you can fill the entire set.
@tsoojbaterdene7793
@tsoojbaterdene7793 3 жыл бұрын
This is the easiest integral I`ve ever seen.
@K_V-S
@K_V-S 4 ай бұрын
*We can keep going on exploring & doing maths .. cuz it only demands three qualities of our mind* 1. *Curiosity to know* 2. *Using only knowledge i.e. No belief system* 3. (most important) *Focused mind to dig deep into the question*
@simonwillover4175
@simonwillover4175 3 жыл бұрын
BirMathGuy: Can I please have a u substitution with a side of v substitution? McDonald's: Here is a ranchburger can some Arby's curly fries someone traded for the McDonald's large fr they couldn't afford earlier. BriMathGuy: Can you gamma me something better? McDonalds: Just d/dx e a l with it!
@ImaginaryHuman072889
@ImaginaryHuman072889 2 жыл бұрын
Craziest part of this video is how you can write backwards on clear glass EDIT: wait I’m dumb you write it regularly and then L/R flip the video. I realized that after I saw a wedding ring on your right hand lol
@nonelast4152
@nonelast4152 3 жыл бұрын
Wait a minute..... Am I dumb or something? Cause how the heck does this guy record his vids? Shouldn't what he's writing be backwards since (I think) he's writing on a see through glass panel? Now that I think about it, he could just be flipping it around.....
@Pod_TM
@Pod_TM 10 ай бұрын
Uniforme convergence isn't the reason you can do the important early swap sum integral, the hypotesis are : if we note u_n to be the function inside the sum (here x^n/n!) Then we can use the theorem under the conditions that sum(u_n) converges (i believe not even necessarly uniformly), integral(u_n) converges and sum(integral(absolute value(u_n))) converges. Not a lot of these has to do with uniforme convergence
@geovannypenafiel1969
@geovannypenafiel1969 3 жыл бұрын
Increíble, pensé que el resultado iba a ser 1 :v
@jessasto947
@jessasto947 2 жыл бұрын
In the beginning was the Word, and the Word was with God, and the Word was God. 2He was with God in the beginning. 3Through him all things were made; without him nothing was made that has been made. (John 1:1-3)
@JayTemple
@JayTemple 3 жыл бұрын
I love the fact that a video about calculus was interrupted by an ad that talks about partials (dentiures).
@BriTheMathGuy
@BriTheMathGuy 3 жыл бұрын
😂
@ejb7969
@ejb7969 3 жыл бұрын
That's because calculus is a subject you can really sink your teeth into! And if anyone is thinking "That joke really bites", I beat you to it. Chew on that one!
@arthurkassis
@arthurkassis 9 ай бұрын
I'm in the sophomore year so I understand anything when start caculus, but I still loving your content, Ive always been ahead of the current math subject of my school so I tjink that watchint this will also help a bit more. For now I'm studying analytical geometry, is easy and I like, and calculus I'll some time soon
@adhipmahanta2583
@adhipmahanta2583 3 жыл бұрын
Felt like ASMR of mathematics
@FunyarinpaFoundation
@FunyarinpaFoundation 2 жыл бұрын
Can we just appreciate that this guy is constantly writing backwards
@divisix024
@divisix024 10 ай бұрын
Remark: One may also justify the exchange of integration and summation via the monotone convergence theorem, by considering the integral to be a Lebesgue integral.
@boutongzheng2926
@boutongzheng2926 2 жыл бұрын
The breezy semicolon principally whisper because piccolo shortly search inside a fascinated creature. feeble feigned, courageous robert
@felipeyoshino6951
@felipeyoshino6951 2 жыл бұрын
Kid: Hold on, dad! Look at this little integral I've found! Dad: Stay away from that, it's just a trap that will make all of us to lose our way home just like those skeletons.
@AliceOutlandish
@AliceOutlandish 2 жыл бұрын
I don't know anything about calculus(only took precal my senior year of highschool) and this is scaring me and I have no idea what's going om
@citizencj3389
@citizencj3389 2 жыл бұрын
What the hell is this integral? LOL....WHY DONT THEY SHOW THIS IN CALC 2?
@dancl8674
@dancl8674 2 жыл бұрын
@ :52 was not explained well… a better way is needed. one shouldn’t just say “ hey let’s replace this with this other thing bc is easier “ that’s what my teacher does and why many kids in US don’t like math.
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