And I had always thought that Michael was so serious! How wrong I was! 🐬 😂
@kpopalitfonzelitaclide2147 Жыл бұрын
Not expecting tgat
@dippn7047 Жыл бұрын
Doing math in his bare feet, living the dream
@conrad5342 Жыл бұрын
Omg he did it again
@it_genfailure Жыл бұрын
got an ad mid flip
@goodplacetostop2973 Жыл бұрын
6:57 and 12:51 Backflips 23:54 Good Place To Stop
@maxvangulik1988 Жыл бұрын
i didn't know michael penn could skidoo
@enpeacemusic192 Жыл бұрын
Omg the backflips are back!
@peasant12345 Жыл бұрын
wtf!
@tzubin99 Жыл бұрын
Yeah, I stopped around the 13 minute mark when the 2319th place is “special” and not some randomly chosen place
@franzlyonheart4362 Жыл бұрын
This looks so funny, I kept rewinding (hit key J) and rewatching a dozen tines, and I was LMFAO watching it. I'm still giggling a bit.
@TypoKnig Жыл бұрын
As a former physicist, it warms my heart to see Stirling’s Approximation in use.
@QuantumHistorian Жыл бұрын
I barely recognised it! In statistical mechanics, _log(n!) = n log(n) - n_ was always good enough, no need to get constants involved. I guess the difference is working with _n_ being about 10^20 rather than 10^3.
@thefunpolice Жыл бұрын
I know someone who called himself TypoKnig well over a decade ago. He was a big Grateful Dead fan and an extremely sharp wit. I think he'd be a little upset that a physicist is using his name while typing sentences containing no typos at all.
@TypoKnig Жыл бұрын
@@thefunpolice You don't know how many edits I had to make!
@thefunpolice Жыл бұрын
@@TypoKnig You're not fooling anyone!
@Kaiwizz Жыл бұрын
Why former? What happened to you?
@bulls6x11 ай бұрын
After watching many videos on this channel, the flip shocked me. I hope you do this in class 😂
@joelganesh8920 Жыл бұрын
To comment on the "sketchy part" where we approximate log_10(1000!) using Stirling's approximation, the wikipedia page for Stirling's approximation gives explicit bounds, which could be used. In the introductory section one such bound is already given: for any integer n >= 1, n! = c sqrt(2pi n) (n/e)^n for some c between e^{1/(12n+1)) and e^(1/12n). Taking logs on both sides, we observe that ln(n!) is ln(sqrt(2pi n) (n/e)^n) + r, where r is going to be between 1/(12n+1) and 1/12n. For large n this error r is going to be very small and hence as long as the fractional part of the actual approximation is not too large (less than 1 - 1/12n) flooring the result gives you the correct integer. (For simplicity I worked with ln instead of log_10, doing it log_10 in fact gives an even better range)
@HagenvonEitzen Жыл бұрын
Indeed, as long as log_10 of Stirling is not *too* close to an integer, we're in good shape. One might however wonder how bad approximations like pi² ~ 10 or e^3~20 are
@leif1075 Жыл бұрын
But that's CHEATING right because if you don't know Stirling you cannot deduce it so there's no way to solve this problem right? I can't see any..o ly how to solve how many zeroes and that the last digit before the zeroes will be an even number so 2, 4 ,6 or 8
@JavierSalcedoC Жыл бұрын
6:58 and that's a good place to backflip
@michaelblankenau6598 Жыл бұрын
Very impressive . Not only understanding how to approach the problem but also the persistence to see it through to the end
@laszloliptak611 Жыл бұрын
Nice explanation. Small comment: At 22:40 to solve the congruence you can simply divide both sides by 2 because 4 is divisible by 2 :). You really only need to use the multiplicative inverse to solve a congruence when the right side is not a multiple of the coefficient on the left. Alternatively, for small numbers, you can find a congruent number that is a multiple of the coefficient. For example, to solve 3x=7 (mod 13), you can use that 7 is congruent to 33 (=7+2*13) modulo 13, so the solution is 33/3=11 (mod 13).
@manucitomx Жыл бұрын
The backflip is back!🎉 Thank you, professor!
@trueriver1950 Жыл бұрын
Why doesn't he get chalk on his clothes using one side of his body to wipe the board each time?
@MathFromAlphaToOmega Жыл бұрын
I was very confused from the video title at first, thinking we were finding the 2319th digit of 1000... This problem is much more interesting.
@gavindeane3670 Жыл бұрын
Same here. But honestly - I think it works. It's much more attention-grabbing than the real title. 🙂
@freewilly1337 Жыл бұрын
I originally thought the digits were counted in reverse order and now I am somewhat disappointed...
@johanvl85796 ай бұрын
Lol yeaa, ig you have to add the 3 nd 1 to get 249 💀
@ingobojak5666 Жыл бұрын
First, the "fact" counting the number of digits needs to be updated to 1+floor(log10(N)). Second, the digit sketchiness is quickly removed by using the improved version of Robbins (see Wikipedia entry on Stirling's approximation): s(n) * exp(1/(12*n+1) < n! < s(n) * exp(1/(12*n)), where s(n) is the Stirling formula. Under log10 for n=1000 this becomes a tiny additive interval that does not change the estimated number of digits.
@Happy_Abe Жыл бұрын
Love the backflip board change
@briandennehy6380 Жыл бұрын
I love these number theory problems thanks Professor
@YagyuBonze Жыл бұрын
love these videos - very glad to see the return of the board-erasing back flip !
@thefunpolice Жыл бұрын
I'd like to see you do a piece on spinor but when you flip, instead of clearing the board it takes all the spinor respresentations and introduces a factor of -1.
@OldSoulClimber Жыл бұрын
The flip is back!!!!
@pseudo_goose8 ай бұрын
You can also skip the mod 5 transformation at the end, note that 2^n mod 10 is a repeating sequence (2, 4, 8, 6, 2, 4, 8, 6, ...) which leads to the same reduction of 2^248 but still modulo 10. Then you have 2a=4 (mod 10), with two candidate solutions, a=2 and a=7
@md2perpe Жыл бұрын
Python code def fac(n): res = 1 for i in range(1, n+1): res *= i return res print(str(fac(1000))[2319-1])
@Darkstar2342 Жыл бұрын
or simply: str(math.factorial(1000))[2318]
@tomctutor Жыл бұрын
Ran it, got 2 quicker than 1 second? But Wolfram Alpha is even easier: 2319 digit of 1000! returns 2 then you can get last digit of: last digit of 1000!/5^249 returns 4 🤣
@JustFamilyPlaytime Жыл бұрын
I'm trying to find a reason that would have me want to know that - and I can't.
@pi2over6 Жыл бұрын
11:43 There is actually a little problem here that lies in substitution cbrooot(20) instead of e. Just because log2(e) is multiplied by 1000 this approximation is not well enough. So the overall result in this approach will be a bit different (2569 instead of 2568)
@mikenielsen8781 Жыл бұрын
I never would have thought of that. Nor would I have thought of doing a backflip. So, an interesting video indeed. thanks!
@biddu2683 Жыл бұрын
Every video here is absolutely gorgeous
@RangerKun Жыл бұрын
Clever grouping at the end there. My immediate thought was to find the prime factorization of 1000!, which uses the same floor(n/p)+floor(n/p^2)+..., but that needs doing work on all the primes up to 1000, so I'd need a computer to get the answer from that point. And if I'm using a computer, I can already cheat and just like you said, just calculate 1000!.
@DrR0BERT Жыл бұрын
I still can't get over the backflip edit. Perfection.
@59de44955ebd Жыл бұрын
Here an alternative solution for the second part, based on the fact that for finding a trailing decimal digit we only have to look at the trailing digits of the factors: after removing all 249 "10"s, we have 997 - 249 = 745 remaining "2"s. And the power table for 2 mod 10 tells us that 2^745 has a trailing digit of "2", since 2^(1+4n) always ends with "2". And this 2^745 gets multiplied by some odd number not divisible by 5, so we now have to find the trailing digit of this odd number. To find it, we only have to count the number of all factors that end with "3", "7" and "9" resp.. We can omit "1" because it doesn't change anything. And there are exactly 100 factors in 1000! that end with "3", 100 factors that end with "7" and 100 factors that end with "9". The power table for 3 mod 10 tells us that 3^100 ends with "1" - since 3^(4n) always ends with "1" -, the power table of 7 tells us that 7^100 ends with "1" and the power table of 9 tells us that 9^100 also ends with "1". And there we have the solution, the digit we are looking for must be congruent 2 * 1 * 1 * 1 mod 10, i.e. it must be "2".
@kanashisa0 Жыл бұрын
I think you are forgetting numbers that comes from factoring 2 and 5 out, like 6 -> 2*3 and 15 -> 5*3, those would contribute to the last digit after factoring 2 and 5 out
@59de44955ebd Жыл бұрын
@kanashisa0 Damned, your are right! Thanks for pointing that out.
@leif1075 Жыл бұрын
@@59de44955ebddoesn't it still work ans what do tou mean by power tables..ive never heard of that..whete did tou learn that..because after you factor put all the 2s you are left with terms ending in odd numbers so isn't your method correct?
@goblinss6652 Жыл бұрын
I thought you count digits from the right?
@gapplegames1604 Жыл бұрын
i think you count from the left because the “last digit” would be the ones place.
@ashleyzinyk399 Жыл бұрын
I'd never heard of Sterling's formula, but I'm proud of myself for getting floor(1000!/p^k) just having seen the thumbnail. I got it from the other side, considering powers of 2 first. I'd considered finding the length of 1000! by summing log(1000) + log(999) + ... + log(1) using a computer, since I couldn't think of a way to group the factors.
@nbjornestol Жыл бұрын
You could try to estimate this sum by noting that it should be relatively close to the integral of log(x) from 1 to 1001. This integral unfortunately is equal to 2568.70, so after adding the 1 from the 1 + log(N)-formula and rounding down (we know we are overestimating), we get that it has roughly 2569 digits, one off the actual digit count. We could also actually note that the integral of log(x) from 1 to 1000 would slightly underestimate the sum log(2) + log(3) + ... + log(1000), which is the same as the sum we're looking for (as log(1) = 0 anyway), but this integral is equal to 2565.70, so after adding the 1 from the 1+log(N)-formula and rounding up, we get that it has roughly 2567 digits, again one off the actual digit count. This would tell us that the actual digit count would have to be 2567, 2568, or 2569. We could now check that the difference between the sum log(1)+log(2)+log(3)+log(4)+log(5) and the integral of log(x) from 1 to 5 is greater than 0.3, so the error we do must be larger than 0.3 and the sum should therefore be larger than 2566, and therefore eliminate 2567 as an option. To eliminate 2569 in the same way, we'd have to unfortunately find the difference between the sum of the first 21 terms and the integral from 1 to 22, so this would be harder to eliminate in this way.
@BobbyC-be9vy Жыл бұрын
Not only mental gymnastics, but physical too!
@davidwright5719 Жыл бұрын
There is a correction term to Stirling’s formula, so you can know whether it is far enough off to change the number of digits.
@neilgerace355 Жыл бұрын
5:32 I wonder if there's a closed form for that infinite sum. For p = 5 we have 249 = 1000 / (5 - 1) - 1 For p = 2 we have 994 = 1000 / (2 - 1) - 6
@chayapholtopar5992 Жыл бұрын
do we have another version that not use the stirling's approximation?
@Nikolas_Davis Жыл бұрын
2:19, well of course you've got the floor, it's your video 😛
@sarmadabbasi77013 ай бұрын
Dear Prof Penn, I am a fan from Lahore. It is good to know that you are in great health and can flip so effortlessly. However, please do it rarely and only in a few videos with proper protection. I feel anxious and nervous that if you do it too often as you might hurt yourself and that would be so awful. We want to see you healthy and in good spirits inspiring us with the beautiful work you are doing. Regards :)
@kevinruggles9180 Жыл бұрын
nice backflip transition
@michelm.1564 Жыл бұрын
Well, nicely done!! Such a clever solution
@tomholroyd7519 Жыл бұрын
I tried and failed to solve this problem when I was an undergrad, I never knew that floor formula. It's sort of obviously right, from your explanation, and the right tool for the job, too.
@c_b5060 Жыл бұрын
I like that you're using chalk and a blackboard instead of a whiteboard. That gives you credibility.
@brucea98715 ай бұрын
You probably know this but there are more accurate versions of Sterling's formula. I have seen it as an infinite series so if you take more terms you will get higher precision.
@Hipeter1987 Жыл бұрын
8:00 should the log_10(N) be inside a floor function?
@goblinss6652 Жыл бұрын
Yes
@euqed Жыл бұрын
It should
@wesleydeng71 Жыл бұрын
Should be just a ceiling function of log(N) (without plus 1).
@Hipeter1987 Жыл бұрын
@@wesleydeng71 of course, even better!
@joelganesh8920 Жыл бұрын
@@wesleydeng71 But then the formula doesn't hold when log(N) is an integer, i.e, N a power of 10.
@davidgillies620 Жыл бұрын
Actually Mathematica on my puny laptop takes 14 microseconds to calculate 1000!
@mathechne Жыл бұрын
very interesting!! An important application of Stirling formula...
@jetx_47 Жыл бұрын
Can’t wait for this to be an olympiad warmup in 296 years
@MatthewBouyack Жыл бұрын
It's been a while since I've seen a backflip transition on here! Nicely done!
@Rócherz Жыл бұрын
*π ≈ √10,* *2 ≈ ¹⁰√1000,* *e ≈ ³√20,* *and that is a good place to stop.*
@holyshit922 Жыл бұрын
Python can do this C# also , C# needs to save source file but compiler and virtual machine which interprets CIL code has been already installed in Windows and you dont need to install extra software
@Enrique-ir4yq Жыл бұрын
I read the title but the with the "!" as an exclamation sign: "amazing! we are going to show you the 2319th digit of a 4 digit natural number: 1000" and I was like 🤔🤔 "1000.000.... and the 2319th is ZERO"
@paulgoogol2652 Жыл бұрын
This is maths. We don't do amazing things in maths.
@rsassine Жыл бұрын
Michael. Was that your first backflip on the channel? Thanks for all your wonderful posts.
@stewartzayat7526 Жыл бұрын
Nope, he used to do backflips all the time in the past. Then he stopped for some reason.
@michaelgolub2019 Жыл бұрын
I have a spelling question: Sterling or Stirling? What is correct?
@FadkinsDiet Жыл бұрын
Stirling with an i for both factorial and thermodynamics
@michaelgolub2019 Жыл бұрын
@@FadkinsDiet, thank you
@rundmw Жыл бұрын
The backflip startled me 😝
@kuebelxd78 Жыл бұрын
I think I came up with an easier solution for the part where you determine the digit, correct me if I'm wrong. Knowing that we only have to look at the last digit of all numbers from 1 to 1000, we can multiply those and look at the last digit that is not a 0. Noticing that we get one 100 times, two 100 times, three 100 times and so on, we can raise each number to the 100th power and look what their last digit is (ignoring the zeros we get from the multiples of 10 because they only adds zeros at the end and we already know we can ignore them). Then you only need to multiply those last digits which gives us 40,320. Ignoring the zero at the end again we get 2 as the digit we were looking for But be warned I calculated that in my head, not with a calculator
@leif1075 Жыл бұрын
I don't see how this makes any sense. You don't get to 100 times or any other number 100 times in 1000 factorial so cpuld.you clarify what youmean? Unless you mean like I reasoned there are 10 numbers nesing in 3 between 1 and one hundred and between 1 and 200 so 10 times 10 equals 100 so you have 100 terms for ending in each digit 0 through 9 between 1 and 1000..is that what you meant??
@leif1075 Жыл бұрын
Wait where exactly did you get 40,320 from?
@FishSticker Жыл бұрын
That backflip caught me off guard
@DanielGomes-sw2fd Жыл бұрын
log10(n!)=log(n!)/log(10) ~ (nlogn-n+log(2pin)/2)/log(10) is precise with error at most (12n)^-1/log(10). With an extra (12n+1)^-1/log10, it is precise with error at most (12n)^-2/log10.
@christianandersson7416 Жыл бұрын
Rxtxxxgr😊
@christianandersson7416 Жыл бұрын
R reexamine twee 3 f ex eeessutom r😬😭😬🤣🤣🤣😬😅🤣😅🇦🇴😅😅Derfex freed 14:25
@christianandersson7416 Жыл бұрын
Jag rfr4fdf ffa 😅rqx, x
@nandoaires Жыл бұрын
Those backflips were absolutely fundamental to validate the proof... :)
@kono152 Жыл бұрын
I love the backflips
@akrickok3482 Жыл бұрын
i laughed and instantly liked the video after the flip. so glad to see it back!
@trueriver1950 Жыл бұрын
It's an act of faith, or at least an act in hope, that the target digit is the last that's not a zero. Had the target been to the right, then the solution would be zero, with less work. But had the target been MANY DIGITS to the left of the last non-zero digit, I'm not sure that we'd be much closer to the goal. (words in caps added for clarity)
@soupisfornoobs4081 Жыл бұрын
This is number theory, the land of shortcuts, I'm sure there's some way to find any digit with relatively little computational effort
@idjles Жыл бұрын
@@soupisfornoobs4081no.
@yurenchu Жыл бұрын
In that case, we do Part II of the analysis in "modulo 100" instead of "modulo 10". (This answer of mine is under the presumption that "to the left" means "directly to the left (of the last non-zero digit)" , rather than "in some specific position to the left (of the last non-zero digit)".)
@trueriver1950 Жыл бұрын
@@yurenchu you've completely missed my point. When you start work on the question, you don't know where the last non zero digit is So you don't know if you'll land on the zeroes, or on the magic digit, not on the digit you are thinking of ... Yeah, and thenif it turns out that it's seven to the left of the last one we can do the analysis using mod 100,000,000. Hardly a short cut. By assuming "immediately to the left" you are still setting out as an act of faith/hope. And my point is that it's an *unjustified* assumption, and you are merely hoping that it will lead (after an initial investment of several lines of working) to a viable short cut. In some situations you might be justified in assuming that the examiner is being kind to you: that's an act of faith, not of mathematics. Or you might simply be hoping. Suppose you don't get lucky: suppose it's the digit where you have to take mod 10,000,000 or suchlike?
@CA-oe1ok Жыл бұрын
@@trueriver1950 The thing about math is, you have to be willing to test out the all kinds of lengthy analysis to go anywhere meaningful and unexplored. Which is why many math profesors encorage and appreciate work that is done 'tediously' or 'brute force', (even more than clever solutions), to reinforce the sentiment in the heads of their students. If you dont get lucky, you try something else. AND dont get hung over thinking that your hypothesis might be wrong and the work you put in could be in vain. Many a times the work you put in will help you determine the correct the path or state for tackling the problem.
@Holasiquetal Жыл бұрын
Impressive. The maths and the flip
@ZX-fg7wb Жыл бұрын
nice. Only problem is the accuracy of Sterling.
@annorome Жыл бұрын
I got a question, which is probably stupid but from a simple observation, we can see, that in the denominator, we took 5 instead of 10, which is factor 1/2 of the original base 10. We easily compute 4. Now, we determine the real modulo (that is: the searched digit), can't we just use the factor 1/2 to compute the real modulo 4*1/2 = 2? Or is that that just a coincidence here? I don't know why, but this is the first maths video, I actually watched through till the end. I'll leave it as a compliment here for a good video! :D
@timothywaters8249 Жыл бұрын
Of course you had a 1 in 10 chance of guessing the right answer from the start... 😂
@youtubeuserdan4017 Жыл бұрын
At first I was like "it's obviously 0, this must be an April Fool's thing", then I remembered that factorial notation exists.
@joshuarowe5571 Жыл бұрын
Surf Arrakis. Fantastic.
@Flea-Flicker Жыл бұрын
Will this work? I got 0. Count the number of 0s at the end of 1000! This can be done by counting the number of 5s in 1000!, since every power of 5 contributes a 0 to the end of the factorial. We can use the following formula to count the number of 5s in 1000!: floor(1000 / 5) + floor(1000 / 25) + floor(1000 / 125) + floor(1000 / 625) This gives us a value of 200 + 40 + 8 + 1 = 249. Divide 2319 by 249. This gives us a quotient of 9 and a remainder of 147. The remainder of 147 tells us that the 2319th digit of 1000! is the 148th digit of the number 10000...00147 (where there are 200 0s after the 1). The 148th digit of this number is 0, so the 2319th digit of 1000! is also 0.
@jamesjjx Жыл бұрын
Can we do a series of projecteuler problems?
@mndtr0 Жыл бұрын
Interesting problem and good video. Btw what chalk is that?
@aaronmorris1513 Жыл бұрын
Going head over heels for these.
@MrGyulaBacsi Жыл бұрын
Dude! What's with the flip? :) Awesome problem and awesome solution btw...
@adgalad25 Жыл бұрын
instant like after that backflip
@ShaunakDesaiPiano8 ай бұрын
7:41: 2319 is indeed special. It’s the code for human contamination in Monsters: Inc.
@cadextheclock246 ай бұрын
i was wondering why no one was making that joke
@jayktomaszewski8738 Жыл бұрын
Never seen the approximation sqrt(10) for pi
@datguiser Жыл бұрын
I’m going to go out on a limb and guess 0 before any math work
@fCauneau Жыл бұрын
Subliminal backflips... Sith or Jedi ?
@thikimhaitran206 Жыл бұрын
Great video !
@jakobscharf6803 Жыл бұрын
Only having seen the title my guess would be the 2319th digit could be one of the many zeroes already? There have to be a bit more than 250 zeroes at the end (because every multiple of five ends up giving us one of the zeroes) So if 1000! is about 2500 digits long the 2319th could still be one of those trailing zeroes.
@jakobscharf6803 Жыл бұрын
Alright having seen the video 1. "a bit more than 250 zeroes" was too careless, I added the 200 fives + 40 twentyfives and reasoned there would be a few more 2. Unexpected backflip! 3. Your focus on the even digit in the middle makes me think that's gonna be our target number :O 4. 2568 - 2319 == 249 :D I guess that means I was wrong 5. Expected backflip! That was some cool math, especially to find that last digit, even if my "easy"(/guesswork) solution was wrong once again :P
@vladthemagnificent9052 Жыл бұрын
came for arithmetics stayed for the backflips
@leofabregues5824 Жыл бұрын
could be nice to precise that actually the first formula is called " Legendre's formula"
@GrandSageSeb Жыл бұрын
Best transitions ever !
@pablojesusmolinaconcha4504 Жыл бұрын
i can't believe the backflips are back!
@Raye938 Жыл бұрын
Saw the title (How to find the 2319th digit of 1000!)and my first reaction was "Huh, he's really excited, but the digit is 0, because it's 1000.00000.......0"
@Neodynium.the_permanent_magnet Жыл бұрын
Some people would count the digits from the LSD (least significant digit) which would make "what is the 250th digit" faster to solve...
@lightninghell4 Жыл бұрын
lmao I thought the exclamation mark at the end was just because he was excited...which then made me very confused.
@ashishsri5884 Жыл бұрын
Is this the actual source of 2319 in the Monsters Inc movie? Not the widely believed white sock?
@brucea98715 ай бұрын
It's hilarious to think in Monsters Inc. they had the same type of emergency response over a sock you would expect for a major building fire. All that over a sock!
@Mythraen Жыл бұрын
I thought for several moments that the exclamation mark in the title was punctuation, and so the 2319th digit of 1000 was zero.
@AbuMaxime Жыл бұрын
That's a good place for a backflip!
@curtiswfranks Жыл бұрын
Related to something which you used here: Let a, b ∈ ℤ⁺\{1}. Which integer powers n of base b are closest to some integer power r of base a: ∀s ∈ ℤ \{r}, ∀m ∈ [1, n-1] ∩ ℤ, |bᵐ - aˢ|/aˢ > |bⁿ - aʳ|/aʳ. In other words, if we fix a and b and optimize r for a given n, which n yield the thus-far best approximation bⁿ for aʳ⁽ⁿ⁾ as we run through the n values (from 1 to ∞, in the integers), relatively speaking? A real-life application of this would be for establishing prefixes. "kibi-" (b = 2, n = 10) corresponds to "kilo-" (a = 10, r = 3). But for b = 2 and a = 10, is this the best correspondence which is available to us (for small n and r)? How big do n and r have to get before we find a better approximation?
@curtiswfranks Жыл бұрын
I sure hope that I formulated this problem correctly. (I do have what I believe to be the answer. Btw, this problem was posed, in slightly different form, and solved by my friend J Diego Suárez Hernández)
@yurenchu Жыл бұрын
Often it will be n = 1, r = 0 (especially if b is small).
@curtiswfranks Жыл бұрын
Fixing a and b, which combinations of n and r score best as sqrt(n² + r²) increases, among every other pair (n, r) ≠ (0, 0)? For example, if the bases are 2 and 10 respectively, then (1, 1), (2, 1), and (3, 1) all do well, but (4, r) will do worse than (3, 1) ∀r.
@yurenchu Жыл бұрын
@@curtiswfranks Ah, you've now edited your comment, and changed the criterion from |bᵐ - aˢ| > |bⁿ - aʳ| , to |bᵐ - aˢ|/(aˢ) > |bⁿ - aʳ|/(aʳ) . That does make a difference. I think the key to the solution lies in the best approximation of ln(b)/ln(a) (or, essentially, logₐ(b) ) by a fraction/rational number . For example, log₁₀(2) = 0.30103... which is quite close to 3/10 , hence 10^(3/10) ≈ 2 and therefore 10^3 ≈ 2^10 . You may want to look into the _continued fraction_ expansion of logₐ(b) , and its so-called _convergents_ . Continued fraction expansion: log₁₀(2) = [0; 3, 3, 9, 2, 2, 4, 6, 2, 1, 1, 3, 1, 18, 1, 6, 1, 2, ...] Convergents: log₁₀(2) ≈ 0/1 1/3 3/10 28/93 59/196 146/485 643/2136 4004/13301 8651/28738 12655/42039 21306/70777 76573/254370 97879/325147 ...
@tomholroyd7519 Жыл бұрын
best way to erase a chalkboard
@davidblauyoutube Жыл бұрын
Yooooooooo great solution development
@wyattstevens8574 Жыл бұрын
"2319! We have a 2319!"
@NerdGlassGamingPA Жыл бұрын
the real question should have been WHY, not How ? :D
@Neodynium.the_permanent_magnet Жыл бұрын
They're back! (flips)
@roberttelarket4934 Жыл бұрын
I don't believe you can do backflips Mike at your age!!! So this is more than likely prestidigitation through some great computer generation!!!
@quarkonium3795 Жыл бұрын
Briefly forgot about the exclamation point use for factorial so I though you were just really exited to show us the 2319th digit of 1000
@frank_calvert Жыл бұрын
omg i thought this was a joke video before clicking on it because i forgot about ! being factorial
@Trizzer89 Жыл бұрын
I could tell you the last digit, the second to last, third to last... It only took me 0.2 seconds
@primenumberbuster404 Жыл бұрын
Now find the 2050th digit of pi. 💀
@soupisfornoobs4081 Жыл бұрын
I can find you the 50 trillionth digit of pi
@trueriver1950 Жыл бұрын
It's between 0 and 9 (inclusive)
@gavasiarobinssson5108 Жыл бұрын
@@soupisfornoobs4081what is it?
@joemcz2564 Жыл бұрын
I trust you know what I'm talking about when I say WHAT WAS THAT
@TheLowstef Жыл бұрын
I like all of your videos but don't always hit the "like" button. But for the backflips - you earned it!