An Introduction to Mathematical Proofs
✍️ This video will give you a basic understanding of how Mathematical Proofs work and what Mathematics University Students usually struggle with at the beginning of their academic career. Now also with (cheap) Subtitles ‼️‼️‼️
❗ A bit of a more beginner oriented video this time around, but one that felt important to me personally. As always: thanks for the patience. ❤
🎶 Massive thank you and shoutouts to the creator of Baba is You - Arvi Teikari for letting me use these fantastic tracks of the game's OST ❤:
- Wall Is Stop - The beginning
- Cog Is Push - Solitary Isle
🎵 other music can be found here:
pastebin.com/VTyn3SEu
Пікірлер: 156
Thank you, Mr Percent! I can finally mathematically prove that 1 = 7!
@electroencephaloctopus
Ай бұрын
Hate to break it to you, but 1 != 5040
@broor
Ай бұрын
I can prove that 6 = 3!
@netanelkomm5636
Ай бұрын
@@broorI can prove that 3!= 7
@FufuZ
Ай бұрын
Assume that the numbers 1 and 7 indicate a summation of vectors, whose starting and ending points are same in both summations. Using the vector theorem, if you start the vectors from the end point of the nose of the number 1 until its foot, you get the summed vector that looks more or less like this - _\_ Again, use vector theorem for the number 7 taking the direction starting from its nose to its foot. We see that the sum is _\_ Both are facing the same direction. If the nose of number 1 is tilted downwards, the length may not be the same between both 1 and 7. However if its straight maybe we can then say its equal. Here we proved that 1 = 7, or _\_ = _\_ , which also means 1 || 7.
@mz00956
Ай бұрын
@@broor I approve of factorial
What you define as a "proof by contradiction" is typically known as a "proof by contra-positive", from formal logic if A -> B then it must also be true that ~B -> ~A. Usually a "proof by contradiction" is when we need to prove A->B so we assume (A wedge ~B) and reach a contradiction (a statement that is always false like (C wedge ~C), and thus A->B is proven.
@0prcent
Ай бұрын
Ah true, we did actually call this "proof by contra-positive" the same thing at uni but i see what you mean. But i guess then this negation of an implication is what i wanted to teach here anyways, just gave it a bit of a wrong name. Thanks for paying such close attention to detail!
@iamreallybadatphysicsbutda8198
Ай бұрын
@@0prcent No problem, I found you from your Jordan curve video, truly remarkable content
@ultimaxkom8728
Ай бұрын
@@0prcent _"How to prove anything"?_ Quite the ambitious thumbnail, though imo out of reach for the introduction. Good 3b1b animation is not a cure-all silver bullet, after all.
@ethanbottomley-mason8447
Ай бұрын
@@ultimaxkom8728 The title is obviously hyperbole.
@ultimaxkom8728
Ай бұрын
@@ethanbottomley-mason8447 Yes, it's clickbait.
got a math olympiad tomorrow and somehow qualified without understanding proofs, but now i feel like im ready. thanks mate
Echoing other commenters, the "proof by contradiction" you showed is actually a "proof by contrapositive." That said, proof by contrapositive is often very helpful. I almost always start with some direct approach, and if that's too difficult, I'll look at the contrapositive. If I get lucky and the contrapositive is easier, I'll write that out, then rewrite it as a direct proof to make it look "cleaner." Aside: Something that's often overlooked is how much reading proofs improves your proof writing skills. I can't count how many problems I've solved by just applying the overall structure/approach someone else used.
there is some magical power in youtube algorithm which suggests me top tier quality mathematical video about topic which is relevant in school with no mistakes nor any delay
@0prcent
Ай бұрын
thank you so much!! (and thanks for the algorithm of course)
Thanks for explaining the "if and only if" part.
Can you prove the riemann hypothesis in a next video? Thanks!
@SlightSmile
Ай бұрын
Yeah this would be really helpful 🙏🙏
@tabiasgeehuman
Ай бұрын
@@SlightSmile very would be an understatement
@deventerprises2640
Ай бұрын
Really helpful for my financial status
nice music choice
@user-sk4kg4hr3k
Ай бұрын
Baba is baba and not you
@turtleboy2150
Ай бұрын
Baba is win?@@user-sk4kg4hr3k
@walyssonbicoli385
Ай бұрын
@@user-sk4kg4hr3k now prove by contradiction (contra-positive)
wow, i really like your editing. the music choice, the graphics, the effects... very comfy. makes me want to study, even
@0prcent
Ай бұрын
aw thanks!
baba is you music is a perfect match for this subject
I never even had this introductuin in my course. Even though this is my second year doing computer science this was very helpfull. Thank you!
This is a very important video. I and many other people struggle with proofs. Thank you.
Really good video, thanks!
@0prcent
Ай бұрын
thank u
good video!, also i love the use of the va11halla OST :3
@0prcent
Ай бұрын
thx! so happy i got to use it in this video :)
@turtleboy2150
Ай бұрын
oooh that's what it is I was digging it the entire time
@0prcent
Ай бұрын
the full music list is also in the description btw if youre curious about any of the other songs
Thanks for covering this.
Incredible man, keep it up.
Great video. Starting my maths journey and this is very helpful
@0prcent
Ай бұрын
all the best!
first time I've heard _Baba is Me_ music in an unrelated youtube video
baba is logic
@totoroangelo0013
Ай бұрын
baba
@IzUrBoiKK
Ай бұрын
Les go you also recognised the bg music
this is such a good video. If this is what proofs are like then I definitely need to take more proof based math as part of my computer science degree.
@0prcent
Ай бұрын
im not sure how accurate my portrayal of the proofs are but if youre intrigued i can definitely recommend it, especially with analysis topics the approach tends to give you a much deeper understanding for whats actually going on
Today is my maths exam. Wish me luck!
@kamalkrishnabaral
Ай бұрын
I will bring 4 gpa.
@filipus098
Ай бұрын
good luck dude!
@kamalkrishnabaral
Ай бұрын
@@filipus098 thanks.
@paperclips1306
Ай бұрын
Good luck
@floge1
Ай бұрын
good luck friend!
Well made video, here's an algorithm boost!
Very interesting video! I will be taking my first analysis class (convex analysis & optimization) and was a bit worried regarding the notation. Thanks!
@0prcent
Ай бұрын
best of luck!
I would subscribe but you are at 3.14 k subs. Love this video btw; there are not enough videos about symbolic logic on KZread.
Nice Video, I think this explains. I'm a Computer Science Student, I already went through this. Proof by Contradiction is bitch, because it's unintuitive. I hoped you would go s bit more into the detail, because I struggled a lot with this. As far as I understand it know, we want the statement to be true. That's why we can say that if the result is wrong, the condition must also be wrong. It's like a second hidden layer most people say nothing about. Same thing about statements without any quantifier.
@0prcent
Ай бұрын
Thanks for the feedback! And also yeah for implications specifically it might be helpful to review the truth table (which i probably should also have covered in this video now that i think about it) for that operator specifically, then it should make sense why we want both the result and the condition to be wrong.
Wow, thanks zeropercent! This helped me prove Fermat’s Last Theroem! I would include it in this comment, but sadly it’s too long
Very interesting, ty a lot
Really appreciate you using valhalla music
Great video 👍
Cool video, goat montage
Tha Baba is you ost is so good
This would have been very helpful on my first year of uni
Great video! However, a few nitpicks. I think someone mentioned that the "Proof of Contradiction" you talked about is actually Proof by Contrapositive. I do think that the entire section on implications is a bit messy. For example, its confusing to call the contrapositive as the "negation of the implication", as well as the visuals seemingly implying that as well (i.e. both "Condition → ~Result" and "~Result → ~Condition") The connection between if-and-only-if part and implications might be misleading as well. The implications you showed in the video are statements in the object logic, whereas the iff-definitions are in the metalogic. Finally, I do think bringing up negation would be helpful, especially during the latter half. It ubiquitous everywhere, even moreso than "and" and "or".
@0prcent
Ай бұрын
i agree the whole thing about the names of different parts of an implivation even got myself confused while i was making the video, should have made that clearer. i dont think the different usages of if only if would be that confusing to a beginner since it wouldnt really matter to them in the first place and i was thinking about also including negations somewhere but it honestly felt a bit too intuitive for me to specifically talk about them, maybe thats not the case but lets see what other people think as well thanks a lot for taking the time to write down mistakes/things to improve like these, ill take everything into consideration and i really appreciate it!
1:45 "... [an AND expression] evaluates to true..." This is, in my mind, where type theory/constructive logic separates from classical logic: `and` doesn't "evaluate" to anything, but it *is* **proven** when both inputs are proven. (Note, I'm not saying you're wrong -- you're absolutely correct in the classical context --, but I'm highlighting a difference between the classical framework, and a constructive one)
Please continue using cat memes and Minecraft in your editting; it succeeds in making the video (and therefore, its subject) more accessible, and they're adorable!
@0prcent
Ай бұрын
aw thank you! glad that helped with not making it seem too overwhelming
As others pointed out you showcase proof by contrapositive instead of by contradiction If you want to prove A=>B, this statement is equivalent to not B => not A The negation of A=>B is "A and not B", proof by contradiction takes those and leads it to a contradiction such as x=/=x, 1=0,... A lot of proofs for implications by contradiction can be easily turned into proofs by contrapositive since many do not use both A and not B in their deductions, only using not B and the contradiction being "since we assumed A and got not A we have a contradiction" This only really matters for philosophical reasons about validity of the law of the excluded middle and the fact that we are assuming math is consistent, but that is the kind of nitpicky math stuff I personally love
Omg no way baba is you music in a math video lmao. Also, what program did you use for the animations?
@0prcent
Ай бұрын
blender for the 3d animations, manim for the math/latex animations and then edited everything in davinci resolve
Very popular methods lecturers use are proof by it's obvious or proof by it's a task for the student to do in home
If you are a nuroscientist watching tjis or someone you know please aske them this or let us know why we feel sleepy when watching scientific or mathematical explanations content or lectures , is it lack of sleep or how we think during the solution or paying attention or something else completly? im genuinly curious
another way of writing if and only if in a sentence instead of mathematical notation is iff. You can say A is true iff B is true
I have the prooof for the Riemann Hypothesis but there is not enoigh space in the comment to write it.
👌
The subject of a proof is a statement that can be true, or false, or undecidable 😉
how these visualizations are made? btw great video !
@0prcent
Ай бұрын
manim for everything 2d/math stuff, blender for general 3d animations and editing in davinci resolve thanks!
@cutepotato4190
Ай бұрын
@@0prcent impressive work :) waiting for more
@cutepotato4190
Ай бұрын
@@0prcent Thanks man
Does formal proofs using computer theorem provers like LEAN4 ever come up in such courses?
@0prcent
Ай бұрын
i havent really heard of any solvers being covered at uni. not sure what kinda course you would have to attend for that but it would certainly be an interesting topic
@mohamedtalaatharb2441
Ай бұрын
@@0prcent Looks like there are only independent efforts by some professors kzread.info/dash/bejne/eHisktCRdrTSn6g.html and there is also the Xena project. I think it might be useful to include it in education because it looks like there is future potential for it. Imagine being a first year student playing that game adam.math.hhu.de/#/g/leanprover-community/nng4
Baba is you OST at the start of the video.
I think that the Z symbol you used to denote the set of whole numbers is actually used to represent the set of integers. Integers include negative numbers where as whole numbers don't. I don't belive there is a good notation for the set of whole numbers.Generally I'll use N union {0}. Where N is the set of natural numbers.
@0prcent
Ай бұрын
oh just looked it up and i didnt know that "whole numbers" was an ambiguous term. integers is of course what i meant but might be a bit of a translation mistake then, thx for making me aware of this
Your students seems like a pawns, lol. Thanks a lot.
Can you teach us how to proof more advanced topics in mathematics too?
@0prcent
Ай бұрын
There are some things i didnt cover here but as a next step it would probably be best to take a look at some actual proofs (my recommendation would be proof-based book tackling a beginner area of mathematics, i started with analysis back then). I could do another video about advanced proof techniques/tricks but my next video will most likely be about something very different and after getting the basics of proofs down, usually the hardest part is just having an idea
now i am subscribed to lowestpercent *and* zeropercent
As an autodidact, this is a pretty good explanation.
0:58 0:59 1something
This video is proof of the creators genius.
its pretty funny bc in france we do this in 9th grade
Baba is you
now i will be able to prove that i cannot prove this statement!
I don't accept the law of the excluded middle. At least not without some qualifications on what objects are involved.
baba is you
oh wow, set theory.
The title is rather ambitious ?
how to prove anything: 1. make an assertion 2. write "QED" you have now proved (1). QED
Just leave it as an exercise for the reader
proof: I made it up cool vid btw
@0prcent
Ай бұрын
thx!
@cozzy124
Ай бұрын
proof: it was revealed to me in a dream
How to prove anything that can be proven (in mathematics)
8:18 You didn't actually prove the statement is true for all n greater than or equal to 0, since when is between 2 and 4 we get false results. For example 2^2>2^2 is false; 2^3>3^2 is false; 2^4>4^2 is also false.
Did you know that 1+1 = 1. ? In bools algebra that is.
2^3 = 8 < 9 = 3^2
What would be point of math if AI or some else technology will write proofs itself like an oracle or omniscient god? It's kinda math philosophy question because all history humanity lived in some math deficit of proved knowledge even if we had many proved things we always have something to proof
Step 1: Accept reality as real... Or MAYBE Step 1: Assume that you can accept your own assumptions as acceptable. OR maybe Step 1: Accept that concepts exist~~~~~ UUh... Maybe... Step 1: Be alive. Step 2: Watch the video.
my biggest issue with proofs is no one bothers to spell out exactly what they are doing explicitly. too often relying on muh context and muh read my mind. i like programming because you have no choice but to spell out explicitly every minutia of your intended meaning. if only the math world could catch up but it is too bogged down by natural language explanations.
@manawa3832
Ай бұрын
i like what languages like coq and agda are going.
@0prcent
Ай бұрын
i know exactly what you mean, i also come from a programming background and the biggest thing im missing in maths is descriptive variable names. in lots of longer proofs its impossible to track all of the A,B,C,D,x,y,z and 10 different greek letters all being used in conjunction.
🙌 P r o m o s m
How to prove anything: step one: assume 1 = 2
Only because the statement does not work for some negative numbers, it doesn't immediately imply that it is wrong. I don't get why this "proof" should be enough. Btw. n^2>=1 is not true for all negative numbers.
@0prcent
Ай бұрын
remember, n is always an integer
Well if i learned anything it definitely proved that I'm a moron and a dumbass. Since i didn't understand a thing despite watching it 3 times
megga bump
österreicher?
@jorex6816
Ай бұрын
Hab ich auch überlegt
I don’t have to do math
…and YT decided to shadowhammer my comment
@mskiptr
Ай бұрын
(and it seems this one got too) edit: this one only partially
First assertion is wrong. Try again.
❤🔥❤🔥❤🔥