/sci/ - Science & Math

first for cull your distractions

Math is only possible to contemplate and engage in if you have a comfy life. Bills, finances, no food.... misery just misery. Even the poor math people had loving parents that would obscure their true conditions and not let the stresses of their life go through telling their boy not to worry and everything is going to be ok and see him off with a meal for breakfast and dinner Try doing math on an empty stomach, needing to cook for yourself once or twice a day or knowing you have 1000 other obligations and duties and it becomes as trivial to you as drawing stick figures. Don't get me wrong, I like math but it simply isn't a realistic or useful thing to do unless you are insulated from the external world. If you have nobody, this requires money. Big money. Until then, I'm abandoning mathematics as it is only a source of pain. To think, it used to be my favorite subject when I was a kid.

>>11817688
https://youtu.be/wuhbxJahVRE

>>11817688

https://youtu.be/wuhbxJahVRE

>>11817733
ill sip 2 that

Are there any problems to autistically hunt down counterexamples to the Jacobi conjecture?

>>11817733
yeah I used to (and still love) maths but honestly I'm 26 now and started working when I was 15, the best years of my life have been wasted worrying about money and just trying to survive. I graduated last year with half a maths degree (joint honours with philosophy) and I think I remember at most 15% of it all. I feel like a useless fucking brainlet and spend most of my days being anxious about how I'm too much of a pussy to kms

Last night i was a bit drunk in the house of a friend and i began to talk about groups in informal way. Shit like what's a group and modular integers as a cyclic group. He was quite fascinated and wanted to know more. He asked me if there are some very informal books about group theory that he could read. He has no knowledge of mathematics other than few thing from HS, do you think that such a book exists?

>>11817582
Classical realizability is also a thing. The difficult part is to get the full axiom of choice but it seems there has been recent successes in this area.

https://www.irif.fr/~krivine/articles/A_program_for_full_AC.pdf

>>11817782

There are definitely books that go from basic math (induction, set theory, whatever) to group theory, but there is not really any way to be more casual than that.

>>11817795
if you could name one i could tell it to him, he can always try. All the books that i used to study group theory are too advanced for a pleb

>>11817786
Thx, I might have a look.
On a semi-related note, I've never found out how e.g. cubical type theories "make univalence compute".

On that note, the two youtube channels `HoTTest` and `Topos` have uploaded a lot of talks in the recent weeks. Here's a Schulman lecture from yesterday
https://youtu.be/VVe6kBztnAs

>>11817805
>On a semi-related note, I've never found out how e.g. cubical type theories "make univalence compute".
It's fairly straightforward, they just replace the inductively-defined equality by a "negative" equality which is morally defined by induction over its argument type. In some sense it's the ω-categorical version of Observational Type Theory.

>>11817805
>Thx, I might have a look.
Also, the whole field of classical realizability stems from Griffin's seminal paper on typing callcc.

https://www.cl.cam.ac.uk/~tgg22/publications/popl90.pdf

This shows that classical logic is *also* constructive in some generalized sense.

>>11817807
Don't really see what that means, unless it's some sort of semi-automatic normal form reduction (which was my first idea of how it could be possible to make it "compute", but I have not thought much about it)

>>11817812
Yeah, blue is also green up to a few nanometers.

>>11817828
>Yeah, blue is also green up to a few nanometers.
Sarcasm won't lead you far. Constructive here means that the proof derivations of the logic enjoy a computational content that is compatible with the typing structure. So, essentially, you have a programming language.

This is not trivial, because you have to be careful in how you define this not to reach a degenerate equational theory for your language. Gentzen's proof of cut-elimination is degenerate in that sense, while the λμ-calculus is not.

>>11817800
>>11817782
The easiest book about group theory that I can think of that's actually good is Pinter's Abstract algebra. It's Dover too so it's pretty cheap. Also has ring theory and even basics of Galois theory, and the group theory exercises iirc have "real-world" applications to error-correcting codes and such, that are pretty cool.

>>11817846
Is there a reason why Dover's books are so cheap? They're of quite high quality, for what they are, so it's always surprised me that they're almost always <$12.

>>11817836
What's the part (presumably a purely classical one) that makes Gentzen steps degenerate?
Or what are those principles that doesn't translate to a constructive type formation rule or what it is.

>>11817846
>Pinter's Abstract algebra
thank you very much, i will give it a go

>>11817854
Something about copyright, so you're basically just paying for the paper and ink

>>11817854
maybe it's the printing quality and the paper, but even some 100$+ springers have shitty quality, or maybe they are old texts. I have a introduction to complex analysis by Cartan which is fabulous and i paid like 10 euros

>>11817782

>>11817854
> Is there a reason why Dover's books are so cheap?
They're not all cheap, just the older books (if you look, they'll usually be originally published in the 50s or 70s).

>>11817854
Almost all Dover texts are scans of ancient textbooks from long-dead authors (whom they probably don't have to pay anything to, although I don't think authors make much from say, Springer books anyway). Between the scanning, the crappy printing and the lack of LaTeX they usually look pretty bad and they're often quite outdated. Some of them are still worth reading though.
Also a lot of times you can find an original hardback sewn-binding ex-library copy of those books for a few bucks more, and being from the 60s or 70s they're going to be excellently printed, which I'd personally rather do than get a paperback photocopy.

just read soviet era books, they weren't supposed to be sold so you're not commiting a crime by downloading them from libgen

>That first sip of the day edition
Actually a good edition.

Does an espresso count for sip'in?

>>11817994
Are any of them in english?

>>11818011
espresso is for queers and frenchmen

>>11817715
Stop making mg threads if you plan on using images that are not math related

>>11818017
Debatable.

>>11818030
>coffee isn't math-related
dumb animeposter strikes again

>>11818030
Ffee *is* a mathematical object, up to duality

>>11818034
This.

>>11818011
Espressos are garbage, why do you torture yourself like that?

>>11818011
>>11818017
>>11818030
>>11818031
>>11818034
>>11818037
>>11818040
>>11818042
Good thread.

>>11818042
Tastes good. I'm not an espresso kind of guy, but I went to my local coffee without an electronic device and thought I keep it short.

>>11817786
He doesn't seem to know how he wants to write realiz/sability.

Any rigorous college algebra or precalculus textbook?

>>11818050
No.

>>11818050
The average mathematician could literally formally prove every statement in a precalc book while overdosing on cocaine.

>>11818050
Lang Basic mathematics, or Axler's Precalculus

Is a golf club a topological object?

What are /mg/'s thoughts on elliptic curves?

>>11818089
i never bothered to learn them
but it's a nice topic

>>11818089
God level fields: SCV, Homotopy Type Theory, Elliptic Curves, Algebraic Topology
Demigod level fields: Homotopy Theory, PDEs, Theoretical Physics (it's pure mathematics these days)
Human level fields: Dynamical Systems, Algebraic Geometry, Set Theory, Logic
Trash level fields: Applied Math, Computer Science

>>11818108
Best introductory texts for elliptic curves?

>>11818108
>Homotopy Type Theory is god level
>Logic is human level

>>11818131
HoTT is going to be the new foundation of mathematics soon replacing the dated logic and set theory, sorry set theorist feog

>>11817718
This thread is my distraction though

>>11818108
Retarded post, consider suicide.
First of all, the best field of all time is metric spaces of non-positive curvature. This isn't up for discussion, I'm imposing my opinion on all of you.
Second of all, htt is a meme.
Third of all, set theory and applied maths are naisu, on occasion.

>>11818197
Pure cope post

>>11818199
The one who says others are coping is the one who's really coping.

>>11818210
>projecting your cope onto others
whatever helps you cope buddy

>>11817715
Any good books on embedded systems, control theory, dynamical systems, or optimization that I should read? I have an undergrad degree in math, and have no interest in formally pursuing graduate studies, but have recently considered working on a project that might unify these ideas, as I've developed an affinity for them.

I have taken a class in optimization before, and used An Introduction to Optimization by Chong and Zak.

Bonus question: Should I try to develop these ideas (for my own benefit) in the language of categories? I have attended conferences on applied category theory and painfully worked through Mac Lane's Categories for the Working Mathematician, as well as various books on a.c.t. by Spivak (David, not Michael) and Fong, though I still struggle with whether or not it is a meme for anything outside of algebraic geometry.

In yesterday's /mg/, Optimal State Estimation by Dan Simon was recommended to me, and a bit of category theory's "use" in computer science and physics expounded.

Hope you all are having a good day or night and my rambling was not too retarded to parse. Thanks.

>>11818141
This is only said by HoTTheads. No one doing math cares about foundations, not even set theorists.

>applied category theory

>>11818215
Thanks for the advice, you seem like a specialist.

>>11818228
That's a bulge

>>11818224
Lol is this a widely known thing? I am >>11818219 and wonder why there are so many MtF in A.C.T. fairly often.

>>11818238

category theory is to math like speedrunning is to gaming

>>11818257
you mean it's for autistic trannies?

>>11817786
>>11817812
Thanks for the links again. I just tried to read them but they are beyond me. Probably because I never actually understood the relation between call-with-current-continuation and Pierce law, despite trying to.

>>11818219
>In yesterday's /mg/, Optimal State Estimation by Dan Simon was recommended to me, and a bit of category theory's "use" in computer science and physics expounded.
I wrote the post when I woke up a few hours ago. But okay it was in the other thread.
Just start getting into the books and jump off to something more relevant to your secret project, I'd say.

>>11818238
It's actually a good question. For one thing, I think the "abstract sheaves" and related topics community was just more open and present on the internet and has a lot of twitter addicts, which is the bubble where they all are vocal. I'd think they are just as common in Java and Rust circles etc.

But isn't it good to see more women in tech? :^)

>>11818257
Maths for physcists is to maths what speedrunning is to gaming.
https://www.springer.com/gp/book/9783540711742
This book's summary makes me laugh for ten minutes every time I look at it.

>>11818274
I don't see a summary there?

>>11818278
I meant the table of contents.
My bad.

>>11818129
bumpan for interest

>>11818238
All mathematics is basically applied category theory

>>11817782
It's funny because often people get put off by calc but I think that the vast majority of people could enjoy and understand upper level mathematics

There purpose of pure maths is to lay foundations for applied maths. Pure maths, in and of itself, has no value, even theoretical cs is better since it focuses on some realizable machine model.

>>11818294
I also think so, but they are also put off by the inevitable technical aspect, the amount time and effort needed to master a subject. Yeah group theory exercises are kinda fun but not many people would enjoy doing them for several hours after a lecture at university

>All mathematics is basically applied category theory

>>11818289
This is true, and why I originally went into the field.
>>11818268
I downloaded that book and began looking through it - thank you for the recommendation. As for the tr*ns question: At all of the conferences I've been to, I have literally only seen one biological female lecturer, Tai-Danae Bradley (though I have talked to a number of others who are currently graduate students under Baez, Spivak, Fong, or Milewski), while I have seen a significant number of trans women. It has almost become a meme where if anyone shows up on the schedule with an ambiguously female name, then they're almost assuredly trans.

>>11818274
book goes from not even assuming what a topological space is to defining paracompactness in less than half a page

>>11818318
Category theory is the least tranny branch of math.

>>11817733
grothendieck litterally grew up in a concentration camp
shut up manchild

>>11818129
>>11818288
Rational Points on elliptic curves by Tate & Silverman?

For what it's worth here's a expediently detailed walk trough how it's actually realized on Bitcoin
https://youtu.be/YZafZ3Rvd8I
see also
http://www.ijsrp.org/research-paper-1117/ijsrp-p7117.pdf
and here a mini tutorial to use the Etherium lib for python
https://youtu.be/FVc-UOHcajc
see
https://github.com/ethereum/eth-keys

>>11818289
>All mathematics is basically applied category theory
>This is true, and why I originally went into the field.
It's not really true in any good sense. I mean it's true in the same sense that "all reasoning is just application of the Sheffer stroke, bre" or "it's all abstract rewriting systems". The theoretical bridge from the foundations to the applications is nothing I ever see anybody walk.

I'm in some chatrooms with Baez and Schulman and those guys, and seemingly they really want to believe that "actually, topos theory is natural and easy to learn, and it just seems hard because we get wired differently from early on by our education", but I'd bet that "up to homotopy equivalence" etc. will always be ugly to formalize and less easy to make sense of than material lego block setty constructions, no matter their flaws.

>>11818324
>Tai-Danae Bradley
Have you been posting here thesis here 2 months ago? I ended up reviewing it.
https://youtu.be/sIy9pD4sTVA

>>11818329
Many such cases.

I got into an argument yesterday, making the case that complex analysis books shouldn't speak of much more than interior of balls - as opposed to stating all integration theorems on the complex plane always already for "open domains [math] \Omega [/math]". I'm not superfluent in the field, but introductory books actually never seem to use much topological theory, so this seems like shitty language.

eum

>>11818350
Thanks!

What's his favourite math subject?

>>11818369
Basic algebra :)

>>11818329
>bro just cram basic topology, differential geometry, Riemann Surfaces, algebraic curves and their moduli, scheme theory and Calabi-Yau in 200 pages.

>>11818369
Combinatorics.

>>11817733
>Try doing math on an empty stomach, needing to cook for yourself once or twice a day or knowing you have 1000 other obligations and duties and it becomes as trivial to you as drawing stick figures.
>A BLOO BLOO BLOO I HAVE TO COOK MY OWN FOOD LIFE IS PAIN
I can't even imagine having such little self-awareness you could type this entire post out and then hit Post afterwards.

>>11818370
she cute

Do yall print your books, read them on your computer or buy them?

>>11818350
I agree with you, and I guess my interest is in trying to walk that bridge, though I'm not sure I'm good enough at math to lead the way for other people to do so. I am an applied mathematician/data scientist professionally and work on this in my free time, so very little harm in trying. I was not the one who posted Bradley's thesis.

Also, hello Nikolaj - small world. If I am not misremembering, I originally met you on an MDE-adjacent discord, and you invited me to another math discord. I will watch your video.

>>11818378
read on computer/buy them/rent from uni library

>>11817715
HOW THE FUCK DO YOU PROVE THE GRACE-HEAWOOD THEOREM

>>11818384
DON'T GIVE ME ANY OF THAT SHIT ABOUT APOLAR POLYNOMIALS, JUST GIVE ME BASIC FUCKING COMPLEX ANALYSIS

>>11818378
I buy them if I can. I don't mind paying $60 for a nice solid copy of a book I'm going to spend months with, but sometimes I want one of those monographs that are $200 or something ridiculous and I'm not going to pay that.
Anything I can't/won't buy I print out. I fucking hate reading on screens.
Also not all books have hard copies (plenty of people just upload books to their websites that are slightly unfinished or just informal) and there's no choice but to print those.

>>11818369
Substraction

>>11818350
>I'm not superfluent in the field, but introductory books actually never seem to use much topological theory, so this seems like shitty language.
It always baffles me why so many people have this compulsive need to blow a nonsensical retarded take out their ass about absolutely every topic even when they freely admit they don't know what they're talking about.

>>11818408
It's called having a conversation, while being as humble about my conclusions as I possibly can.

>>11818369
PDEs

>>11818378
Buy

Why are tensor products so scary?

>>11818350
>It's not really true in any good sense.
Yes, it is.

>>11818350
This does make me wonder if you can rederive the theorems for integrals along arbitrary open sets by doing shitty approximations with unions of open balls (i.e. you split up the integral as a sum of ball integrals minus the integrals along the intersections and show that the theorems work because the intersection vanishes).

Also, reminder that Riemann mapping is a thing.

>>11818425
Elaborate.

>>11818432
Well I think without further machinery, the ball approach would get annoying as soon as you discuss functions defined on C with some isolated points removed. Eventually you'd want to talk about the domain and probably make use of the fact that amounts to saying it's actually also open w.r.t. topology induced by said balls.

My point came from discussing an early proof in
https://www.fing.edu.uy/~cerminar/Complex_Analysis.pdf
which is a very basic complex analysis text, which however presumed topology language, despite it seemingly making little use of actual topology. The fact that the topology on C is a set of subsets with this and that coherence property is an unnecessarily load to import when you're just generalizing derivation of functions beyond R.

Either way, I have no stake in the discussion and don't say I'm certain that my approach would improve the book.

>>11818422
Because you're a brainlet

>>11818448
>Elaborate.
>Claims I'm wrong
>Provides no arguments whatsoever that gives any basis for his claims
>Demands me to elaborate
That's not how it works, if you put so little effort into your post then why the hell should I write a long ass reply when I know you'll probably answer with more one liners?

>>11818457
jee, you seem grumpy today.
Well you don't have to, I was just interested.

lin.alg:

are there any tricks to know if i want to use the PAP^{-1} characterization of diagonalizability instead of the eigenspace/vector one? i don't understand the latter very well, and hence i struggle to use it...

>>11818070
Thx

>>11818473
I'm sorry, my mental health is affected today

Why are the Sylow theorems so comfy bros?

>>11818378
I used to print when I had access to uni printers, now I would have to read them using electric devices, so I stopped reading them altogether.

>>11818524
They just are.

>>11818483
does this and related threads help?

https://math.stackexchange.com/questions/1324053/what-is-the-difference-between-using-pap-1-and-papt-to-diagonalize-a-m

Do you mean use in calculating things in praxis or use in proofs of theorems?
In the former case, there's actually a common trick in applied linear algebra where you through away some factors of a decomposition, as the characteristic data that you're interested in is of smaller rank than what you want to know.

>>11818498
get well

>>11818544
>get well
When I die maybe... Hopefully...

>>11818544
in the latter case (proofs) mostly, and frankly i dont see how the link helps in my case.

im mostly just suspicious if i should actually be using that characterization because i keep failing with the former version

random: but i detest eigenvectors/eigenvalues and i think they are the first stop into what makes lin alg less pretty, but perhaps i wasn't taught it well / i am a doof....

Today I'm reading
https://www.researchgate.net/publication/341946456_PREDICATIVITY_AND_CONSTRUCTIVE_MATHEMATICS
by Laura Crosilla.

For the guy who complained about the lack of mention of System-F in the Feferman text (RIP), this one is really into Coq.

>>11818562
I can't quite imagine linear algebra without eigenvalues, actually.

For proves, I expect the elegance of an expression like [math] PAP^{-1} [/math] comes to fruition once you take powers of that thing and P's cancel.

>>11818557
It is...inevitable.

>>11818448
>despite it seemingly making little use of actual topology.
You read one proof in chapter 1 where you didn't bother to take 5 minutes to figure out why the topology matters and now you're shitposting about how the entire book would be better off with the topology cut out. It really doesn't seem plausible to me that you don't see how stupid this is.

is there anything more comfy than going down to McDonalds with your notebook and work on some problems?

>>11818587
>It is...inevitable.
As all things should be.

>>11818604
>not going to a pretentious hipster cafe and sipping overly expensive artisanal coffee while you work
my campus has like a dozen of them

>>11818587
i suspect that e.vectors are poorly taught, or at least, they don't directly inform the intuition....

one particular gripe/question i had was that: why did they tend to focus on the e.value, and not the e.space it represents, when the e.value only seemed to be useful for labeling the particular e.space (from what i understand)

This fucking man, just finished reading an introduction to his thoughts on mathematics, holy fucking shit, how could someone be so fucking intelligent? Every damn mathematician should read him, mathematics is all just a game of words in the end.

It really is amazing, the guy singlehandedly killed both philosophy and mathematics

How do I memorize the Cayley table for quaternion multiplication?

>>11818618
>not bringing a foldable desk and a basket of food while you sip white wine, solving your next major proof

>>11818620
You know he retracted his theory about 'personal languages' in Investigations of Philosophy, right? That being said, yes, he was very intelligent.

What's a good resource to make sure that I can just read all the math gibberish?

>>11818625
Derive it from i^2 = j^2 = k^2 = ijk=-1.

>>11818562
since im already here, might as well ask: can the square of a non-diagonalizable matrix be itself diagonalizable? i know its not true in the case of regular matrix mutiplication, but i dont know how to prove in the case of a square...

>>11818643
how about the matrix [[0, 0], [1, 0]]

>>11818635

>>11818645
ah, should have added det \neq 0, but i was hoping that i didn't need that

best math textbooks relevant to biostatistics
any biostatisticians here?

>>11818637
The Napkin

>>11818661
that he retracted most if not all his early works in his latter years is very well-known; though this doesn't strictly discredit his older/newer work

should i start learning math with gelfand?

>>11818645
>implying the zero matrix isn't diagonal

>>11818618

i literally cannot work properly without a big mac in my belly, it's just how my brain works

>>11818662
oh wait lol nvm.........

>>11818673
K, but anyone who believes he didn't kill philosophy completely has misunderstood him.

>>11818604
Never tried McDonald's, and most likely never will, but petrol stations are comfy.

>>11818625
You can derive it from the knowledge that following this chart clockwise for multiplication produces the following unit, and following it counter-clockwise for multiplication produces the negative following unit.

>>11818667
this is the math general

>>11818682
>U CANNOT TALK ABOUT NUFFIN
>lol philosotards btfo......

>>11817715
solve to prove you're not a retard:
there are 5 cards with number 0,1,2,3,4 on it, John chooses 3 cards at random, what's the probability that the number is going to be a three digit number

>>11818686
fuk bru mb mb im on percs' rn for pain thought this was med

>>11818683

>petrol station

Yeah I don't expect a brit to appreciate the enviroment of discovery a McDonald's brings

>>11818691
I will prove I'm not a retard by not posting a solution to the question you poorly paraphrased from your discrete math homework

>>11818696
Not a brit, sorry. Better luck next time.

>>11818661
Mate that's some well known stuff
>>11818682
>>11818620
You read an introduction. Have some humility man

>>11818691
4/5?

>>11818684
Based chartposter.

>>11818731

(she should be able to solve this)

>>11818731
bros... we are denied our deserved fame... we need to setup 4chan mathematical journal...

>>11818731
Kek, someone undid what she did and 2 minutes later she took it off again. What a bitch

https://en.m.wikipedia.org/wiki/Special:History/Superpermutation

Imagine being mad about 4chan and discovering who Teichmuller spaces are named after

>>11818369
Number Theory
He brags to women during sex that it has absolutely no applications and then when they start to bring up cryptography he gets up and tells them to leave.

>>11818731
Unironically based.

>>11818731
>She/her

>>11818643
good question - I guess the answer is no (after trying some examples with candidates for a counter-example on wolfram alpha), but I can't give you a sharp reason

>>11818620
I'm not sure this stance has a good justification, but I'd like for that to be "true" too. It's a clear view. Not sure if it can hold given the effectiveness of math, though. I think we have to introduce some coherence insight of the world, that it somehow ties to logic in more than just rewriting rules? no?

>>11818731
>>11818739
she (or whatever) just conflates source of information vs. source of matter

>>11818746
Brouwer is also accused to be quite the Nazi, but I've not researched into this

>>11818746
Who are Teichmuller spaces named after?

>>11818731
>you can't use a 4chan post proving a result as a source
Why, tho? What's her actual issue with that?
It's one thing if anon is claiming some random historical or physical fact, right, but I don't see the issue with using 4chan as a source in maths.

>>11818731
the power of anime is on our side

>>11818761
Because 4chan is racist and sexist obviously

>>11818770
well it's not wrong

>>11818761
look at her profile, she is clearly a 'woke leftist woman' who works in software so she has 100% heard some normies ree about 4chan being a white supremacy website, and so her tiny, irrational female brain's first reaction to someone sourcing is 4chan that is an act of white supremacy and must be silenced/removed at all costs immediatly.

>>11818731
Is she an administrator in Wikipedia or something? What can we do about it lads? Can we sue them for defamation or something?

>>11818778
The article isn't locked (obviuously, because nobody gives a shit about math)

https://en.wikipedia.org/wiki/Superpermutation

In the top right you can click View History to see the change and edit/revert it in Edit

>>11818788
stop vandalizing her edits you fucking incels

>>11818759

don't go out bring down statues but ... let's say he had some criticisms of the jewish peoples

>>11818793
Fuck off simp

>>11818770
Yeah, but so is reddit.

>>11818793
Wow I bet the Incel article that she moderates is extremely fair and balanced and not at all a smear piece that spits on lonely and undesirable males.
I'm not even gonna look at it, I don't feel like getting angry today.

>>11818794
>For they do not desire to see new greatness emerge: their means of preventing it is to say 'Behold, greatness already exists!' In reality, they are as little concerned about this greatness that already exists as they are about that which is emerging: their lives are evidence of this. Monumental history is the masquerade costume in which their hatred of the great and powerful of their own age is disguised as satiated admiration for the great and powerful of past ages, and muffled in which they invert the real meaning of that mode of regarding history into its opposite; whether they are aware of it or not, they act as though their motto were: let the dead bury the living.

>>11818683
Why are you posting that girl if you’re not going to say things with a posed look you FRAUD.

>>11818770
4chan here.
I jacked off to an Asa Akira video once,so I'm actually not racist or sexist.

>>11818807
>I'm not even gonna look at it
typical white supremacist terrorist baka

>>11818770
>Racist
I don't hate anyone, I just acknowledge scientific research that shows that there are differences in intelligence and physique.
>Sexist
But we love women, we just don't believe they should have the same rights as the ones who literally founded the entire western civilization for 6000 years

>>11818818
>differences in intelligence and physique.
Between races

>>11818818
Cope.
Nigerian-Americans far outperform whites.

>>11818810

what did he mean by this?

>>11818825
Sorry, I have science and history backing me up

>>11818807
>>11818817
Literally nothing wrong with that.

>>11818811
You think I don't pose like that dozens of times a day? I even start and end all my weekly sessions with my supervisor like that.

What will mathematics looks like in one hundred years? What's the field of the future?

>>11818818
oh no a gamer

>>11818696
>enviroment of discovery a McDonald's brings
What, like niggers and ghetto culture? Or maybe in sjw cities more niggers and fat purple haired sjws?

I seriously need a hobby lads, what do

Man, Molly is cute as fuck, I wish she was my gf, I can already imagine we both cuddling in bed during winter reading and laughing at the incels on /mg/

>>11818857
Learn an instrument and start reading philosophy.

>>11818864
>Learn an instrument
Already play the violin
>start reading philosophy
Just finished an intro to Wittgenstein and he just destroyed philosophy for me

>>11818857
Look into electronics. You know like putting wires, resistors, and ICs on breadboards and making little shit that blinks, beeps, and boops.
>>11818859
Wow look at those dead eyes...
This woman has to be a sociopath or something

>>11818864
what's a based instrument that's also relatively cheap

>>11818867
Violin, but it's near impossible to learn alone

>>11818857
I'm partial to picking up heavy things and then putting them back down.
Casual team sports are fun too.

>>11818866
>Wow look at those dead eyes...
???
Her eyes are completely fine you fucked up incel, he shy smile adds a lot to her cute nature, damn I'm in love

>>11818859
She looks like a jew.

>>11818871
I used to do both of those, but slowly going mad with the lockdown
also had a guitar, but lost it (long story)

>>11818879
>jew
Good, Jews are more than half of nobel prizes and fields medals, it means she would bear intelligent children

>>11818879
>she

>>11818855

maybe you should move man, McDonald's where I live is just a normal restaurant

>>11818857
I wish I had a hobby other than posting to these threads with a decreasing quality.

>>11818731
Went and checked the revision out of curiosity.
Not only did she pull the 4chan link, she also pulled a tweet about the 4chan post. So now the citation for "Robin Houston tweeted" is no longer Robin Houston's tweet, but an article linking to Robin Houston's tweet.

>>11818859
Wait a sec, I just realized she says she's "queer" in her twitter profile, what exactly does this mean? She's lesbian or trans or some shit like that?

>>11818884
This.

>>11818915
>she

>>11818915
queer just means you assign victim point to yourself, it's extremely practical. don't need to explain shit

>>11818915
she is open to choking and rapeplay in the bedroom and will cry actual rape 12-18 months later if you are below 7/10 facially

>>11818857
learn an instrument

>>11818915
I'm gay and I think >>11818929 is right on this one. I don't really consort with the types that would describe themselves as queer, that said I've never found someone who uses the term queer and is anything other than straight or prison-bi.
>>11818894
I found this video of Robin Houston linked in his twitter post replies. It's pretty interesting.
Also he's kind of cute with the awkward and modest way he acts honestly...

Hey, can you keep this discussion out of /mg/?

There's already a bait thread about this Wikipedia issue, I'd like the thread to be math or at least anime related, not political opinions

>>11818934
What if I actually rape her but I'm a 9/10 facially?

>>11818915
Queer means "I am straight and cisgender but I want to mooch some oppression off the LGBT community"

>>11818934
>she

>>11818949
then it becomes a fond memory to cherish when she is well past her prime

>>11818948
/pol/ has ruined this entire site, unfortunately. Not even /mg/ is safe.

>>11818948
I'd comply with this but every time I come into this thread asking for advice I get a single reply by an autistic bully with an anime picture, so the answer is no.

>>11818962
>>11818958
>getting bullied by autistics trannies and fat 90 iq faggots
You need to go back desu

>>11818962
>an autistic bully with an anime picture
Literally who? Unless you mean the long gone Yukari poster.

>>11818972
What happened to him, anyway?

>>11818978
No idea. I sort of love-hated him. His posts were good but made me feel inadequate.

>>11818857
Learn some language. Just hour a day. Anki makes it bearable if you hate bare memorization as much as i do

>>11818859
Cute
>>11818962
The animeposters have been nothing but nice to me
I'm expecting that to change maybe

>>11818962
>I shit up this place with >>>/pol/ because someone tells me to fuck off whenever I shit this place up with >>>/adv/
Truly, the perfect excuse. The most immaculate of victims.

>reading a maths textbook
>author says a statement is obvious and doesn't prove it
>I find it highly nonobvious
>spend a long time trying to prove it
>no success
>decide to look for counterexamples, just in case
>find one in less than a minute
>turns out it's not obvious at all
>turns out it's actually false
>turns out the proof doesn't work at all because it crucially depends on the obvious lemma that is false

>tfw realize maths are just boring MMORPG quests where they give you instructions to add or remove numbers to things and retrieve Y to have this new autistic shiny number symbol which then you can use in new boring quests
>tfw mathematicians are just autistic people who like pen and paper RPGs

>>11819055
>reading a maths textbook
>tfw the author likes to play mental tricks and fuck with the readers
>tfw is a lot of fun
>tfw realize most teachers and text books are just fucking awful at their job

>>11819047
You have now become an autistic anime bully.

>>11819055
Which book was it?

>>11819057
Nothing wrong with that. Theorems are spells you invoke.

>>11819075
show boypussy

any good textbooks that are very rigorous yet for absolute beginners?

>>11819077
Not for you to see.

>>11819081
Herstein's algebra book.

>>11819084
weeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

>>11819075
>Which book was it?
Inter-universal Teichmüller theory IV, Corollary 3.12

>>11819067
Post book

>>11819094
Well hello there, Peter!

>>11819104
Spanish only

Now you can feel like a true intellectual by feeling blueballed for wanting to read a book in another lingo

>>11819055
I've never yet encountered a false proposition in a book but I've encountered plenty of false exercises. Usually they can be patched if you add an extra assumption the author probably just forgot or wasn't careful enough to notice but occasionally they will tell you to prove something that's so false it can't even be salvaged.

forgive my stupidity, but is there a way of factoring out the elements of a diagonalizable matrix A, of (PAP^{-1})^{-1/2}, of which P witnesses to A being diagonalizable?

>>11819139
please try again but ask in English

>>11819128
I speak spanish as well anon. Pls gib

>>11819128
I can read spanish, just post it.
I wanna know if the author just forgot a hypothesis.

>>11819139
>[math](P A^{1/2} P^{-1})^2=P A P^{-1}[/math], dum dum.
If A is diagonal you can take square roots pointwise.

>>11819139
>>11819140
>>11819171
i mean as in: if A is a diagonalizable matrix, PAP^{-1} is diagonal, then is there a way of expressing (PAP^{-1})^{-1/2} as a product of elements?

>>11819220
>product of elements
Again I don't know what the fuck this means.

If PAP^{-1} is diagonal with the eigenvalues of A on the diagonal then [math]\sqrt(PAP^{-1})[/math] is diagonal with square roots of the eigenvalues of A on the diagonal, and if you want the inverse for some reason then just flip all the elements over.

>>11819155
>>11819158
It would take me a few hours to scavenge for the name of the book

I took a pic of some of the exercises at the beggining of the book

It's highschool maths so it's nothing really useful but I was fascinated how the author would throw you off by using tricks like repeating a number enough times that it makes you think thats the answer for an equation when its not or how progressively the difficulty would become like it was vidya or something

I had a lot of notes on how would I make a maths text book if I made one based a lot on the stuff in this book

>>11819084
So you admit to letting people see it. What a slut.

>>11819250
how does one not show boypussy or pussy in general when fucc-ing? unless you keep it under the sheets

>>11819244
>product of elements
as in product of matrices. i would go more in depth but i don't want to spoil too much of my homework lol

>>11819244
well actually, is sqrt(AB) = sqrt(A) * sqrt(B) true for matrices? i feel bad for asking LOL

>>11819272
No. The square roots on the right side don't even have to exist.

>>11819245
eso que? estás ayudando a tu hijastro e su tarea de susana distancia?.

>>11819250
Only one person and he only posts on Dvach, so you are not him.

Life is cruel, I can't find this paper. He wrote a bunch of papers with Blakers and I only hit those by googling and this one I can't even seem to find on Sci-Hub...

>>11819296
Now that I think about it, I haven't tried looking for that congress thingy...

>>11819289
No

I was sent to special education classess because they think I am retarded and refuse to do any academic work

I just want do camp and sell hotdogs for a living and hoard all of libgen (and not read any of them)

life so hard

math fuel

>>11819296
>>11819303
https://www.mathunion.org/fileadmin/ICM/Proceedings/ICM1950.2/ICM1950.2.ocr.pdf
p. 375

>>11819329
show bp

>>11819329
Kill yourself.

>>11819329
41%

>>11819329
You know that's illegal by most countries's laws, right?

>>11819335

binomial product?

>>11819341
70%

>>11819333
I just found it after posting. Thanks anyway.

>>11819329
Where's the time stamp?

>>11819329
cool bait
https://twitter.com/translifeishard/status/1071230497437704192

>>11819245
That's been rather standard in my experience, but it's nice you find it fun

Proof your existence

yeah i literally just got the first hrt picture i got on google images you hysterical bitches

>>11819358
There were a lot of tricks and fun shit in that book I swear

I wanted to buy it but the only place I know they sell it is closed atm due to corona so I am super cucked atm

>>11818884
You should be aware that having children with a Jewish woman means that your children will be Jewish (per Jewish custom), and her family will fight for influence over them and denigrate you as their goyish father. This is a warning that I encourage you to heed.

https://strawpoll.com/cj4y5xz4r

>>11819367
You should still kill yourself.

Question about notation.

Say that I have some finite discrete values [math]\{ p_1, \ldots, p_n \}[/math] and I want to sum up the absolute values of all the negative ones only. I can write [math]\sum_{ i : p_i < 0} \left| p_i \right|[/math] and everything is bueno.

But how the fuck do I write it if I have a continuous measure? I want the same thing, just an integral of the absolute values of the negative terms. Does it make any sense to write something like [math]\int_{\nu(x) < 0} \left| d \nu(x)\right|[/math]

>>11819380
I'll make them into catholics.

>>/sci/thread/S3751105#p3751197

Holy fuck the archived thread has been spammed to hell and back

>>11819492
look up /g/ as well

he has been going for months

If you bring up the problem into the regular boards he will do control damage saying how its normal that this happens and how its babies first time on the internet if you see stuff like this and so on and so on

my bet is for a /x/ schizo

>>11819444
let
[eqn]\nu_+(x) = \rm{max}\{0, \nu(x)\}. [/eqn]
Then
[eqn]\int \rm d\nu_+[/eqn]

>>11819492
What the fuck is that? I thought Warosu was just an archive, you can actually post there in old threads as if it's an imageboard?

>>11819503
actually that integrates over the positive values but you get the idea

>>11819492
>He barely had any replies at the time
>No one understood his genius
>No one showed it to elite in the academia
>Took them years until some guy found it by accident and saw how important it was
Is that guy our generation's Cantor?

>>11819507
do make sure your negative subsets are integrable first however

It'd make more sense to formally introduce the negative subsets by letting
[eqn]M = \{n \in N : n < 0\}[/eqn] and then integrate over those subsets

[eqn]
\int_M \rm dn
[/eqn]

>>11819506
You can do that in some (?) of the archives yeah

>>11819525
Who the fuck thought that was a good idea?

Can I have some help interpreting what exactly this last part is saying?

[math]Let\ \sigma\in S_6 \ be \ \sigma=\begin{bmatrix}1&2&3 &4&5&6 \\4&3&5&6&2&1 \\ \end{bmatrix}[/math]

It then says "therefore, find the order of [math]\sigma\ is \ S_6[/math].

I'm not sure exactly what that means here.

>>11819514
I don't think the "spam" comment referred to the 2011 poster

>>11819581
I would think it should be the order "in" S6, the order of [math]\sigma[/math] being the smallest positive integer such that [math]\sigma^n = e[/math] .

>>11819581
I maybe the "is" is an in and they want your to see that [math] \sigma \circ \sigma = e [math]

[math] \sigma \circ \sigma = e [/math]

>>11819600
The order of that permutation is 3, not 2

>>11819602
yeah tru

>>11819596
>[math] \sigma \circ \sigma = e [math]
The second tag should have a / before math

>>11819638
yeah thanks.

>>11819539
I can kind of get why they would do it but it's a terrible idea in practice

Hello, Calculus 1 fag here.

I understand why the slope of the normal line, being perpendicular to the tangent line of the graph, is the opposite sign to the tangent, but why is it also a reciprocal? For example, if the tangent slope is 7/5, why is the normal slope -5/7, instead of just -7/5?

>>11819813
Is it normal that I'm doing a masters and can't answer that question? Kek

>>11819813
This question gets answered in linear algebra.

>>11819823
Lmao

>>11819823
Kek

>>11819813
If you wrote down the vectors corresponding to those lines, they'd be 7i-5j and xi+yj, and then you want the dot product to be 0 (normality), so 7x=5y, or y=7x/5.

>>11819813
Because that's how lines work.
Didn't you learn this in middle school?
https://www.varsitytutors.com/act_math-help/how-to-find-the-equation-of-a-perpendicular-line
>>11819828
>linear algebra

>>11819813
>but why is it also a reciprocal
It's not an "also", perpendicular lines always have negative reciprocal slopes to each other.
This is best explained by using the vector form of the equation but you could do it with baby geometry if you wanted to.

Draw a vertical line through x0-1. This intersects the normal and the tangent. Those two points and M form a right triangle with coordinates (x0-1,y0-a),(x0,y0),(x0-1,y0-b), where a is the slope of the tangent and b is the slope of the normal. Pythagoras on this triangle will spit out ab = -1.

>>11819813
Negative flips over horizontal
Inverse flips over vertical
Try plugging in -x, y, and -y for x in a non-symmetric function and playing around in desmos

>>11819882
I love Desmos so much, bros.

>>11819890
You will like mathematica a lot more bro

>>11819891
>m*thematica

oi-ler
ramoo-nagen
le-bag

>>11819897
What are the best free(as in freedom) alternatives?

>>11819910
use sage

>>11819916
I am already using Sage actually . Just wondering what other people think some alternatives are, would like to take a quick look.

I just want to let you guys know that this is my favorite community on 4chan.

>>11819926
fuck you too

>>11819926
But it's getting shittier each year

>>11819926
as long you're not a tranny ily2 anon

>>11819962
Not a tranny.

>>11819926
Agreed.
Rest of /sci/ is also generally good but this thread is unique.

>>11819926
It's pretty nice when people don't sperg out

>>11820061
>this thread is unique
Can we prove this? Or else express it numerically?

>>11820090
there's some Choice involved (i.e. it's not actually true)

>>11819910
>>11819921
I've been playing with octave and it's pretty good.
Free software math programs are so comfy.

>>11819980
<3

from me

2

(you)

Hey everyone, I'm interested in learning about geometric/grassman algebra after being memed it on GitHub. Where should I start? The highest math classes I took were Calculus III and Linear Algebra and Diff Eq, several years ago. I'm a CS brainlet so I never actually used any of that math.

>>11820318
>CS
>Not using linear algebra and vector calculus

>>11820497
>Implying that CStards know anything about those subjects after the grade appears on their transcripts

>>11820090
{n|n is a post ID in mg}

Good morning /mg/

>>11820983
Now that is an irrefutable argument!

chad

>>11821218
very based, who wrote this?

>>11821228
my diary desu

Someone make a new fucking thread so I can ask for help with my homework already

>>11821228
>>11821238
Masaaki Yoshida, Hypergeometric functions, My Love.
It has some amusing passages. Pic related is the page of dedication.

>>11820061
>Rest of /sci/ is also generally good

>>11821442

>Heiter

>>11821442
good boy Fuku *headpats*