#serious-discussion

1 messages · Page 357 of 1

south dawn
#

can lambert help us

magic python
#

Wait what is a formula then for it

#

Using non elementary functions

south dawn
#

for quintic?

#

tberes one

#

theres

#

its like the fountain of youth tho

magic python
#

Like obviously you could define a function and just say it's output is the roots of the polynomial

south dawn
#

u gotta be juan ponce de leon

magic python
#

But what is a well defined way that isn't approximation?

south dawn
#

million dollar question right there

magic python
#

Sadly not

south dawn
#

with things like the lambert W function and the erf its been studied and it can be graphed in the complex plane

neat lintel
#

What’s the integral of

1 over ln(x) dx?

#

It looks simple tbh

worldly horizon
south dawn
#

can we get rid of the absolute value

#

pretty please

neat lintel
#

yeah
I found that out and shit felt like I was standing on the edge of it hah

worldly horizon
#

even if you do it’s non elementary

#

you’d need the function li(𝑥)

neat lintel
#

Which is larger

e^pi or pi^e

south dawn
#

i found something interesting

neat lintel
#

by intuition only

neat lintel
south dawn
worldly horizon
magic python
#

We really just defining whatever now, huh

vast wraith
south dawn
#

for those who are curious

magic python
#

Wow uhhh so a multivalued series?

vast wraith
#

no, that is just one of the solutions

magic python
#

Awww 3:

#

Sad

south dawn
#

if u have one of the solutions could it not be reduced to a quartic with the one root factored out?

#

either long division or plain factoring

magic python
#

Yes ig

left patio
#

how it feels seeing Riemann get glazed just for plugging complex numbers into the oiler zeta function.

tidal acorn
#

Hello

#

Wait it didn't embed

#

can someone post it embedded pls

#

:(

left patio
#

mathematics dc can’t afford embeds

#

too expensive for our unemployed asses

tidal acorn
#

fine then just go to the link to see the gif or whatever

gritty heath
left patio
#

goatler solos

tidal acorn
hallow plume
#

why lol

worldly horizon
patent phoenix
#

I'm thinking of learning Lean before my Discrete class next term. have any of yall learned it?

#

and how helpful is it

surreal sapphire
#

what kind of benefit are you hoping for

#

i dont see how knowing lean would be particularly useful

patent phoenix
#

discrete is an inherently proof-heavy/logical class

#

was wondering if lean would help w this

surreal sapphire
#

not really

zealous bronze
#

for an intro discrete math class

#

if you want to learn it independent of that then yeah do it

patent phoenix
#

I was thinking if I have exposure or practice of learning how to write theorems and proofs in lean, that skillset could benefit me in discrete

#

i realize now that this isnt a property of just discrete tho lol

#

ig i could learn it just to have it

zealous bronze
#

kind of, but the way of writing proofs in a proof assistant is different

surreal sapphire
#

humans don't write proofs like you do in lean

#

its almost always significant extra work

patent phoenix
#

hmm

#

maybe i can absolutely flex on my teachers

#

(im joking)

turbid sedge
#

go work bih

rose ridge
turbid sedge
#

NAW

twin meadow
#

Hi CHATTT

#

how's everything going

neat lintel
#

It’s dead

worldly horizon
worldly horizon
#

hbu?

viral oracle
neat lintel
viral oracle
neat lintel
#

Weird ahh stickers

twin meadow
viral oracle
#

lol

worldly horizon
small dust
viral oracle
small dust
viral oracle
small dust
dusty lark
#

Best way to unbias yourself is by randomly generating opinions.

old oak
#

Depends on the distribution

neat lintel
#

lol

silent junco
#

nope

#

not allowed here

#

no? youre just not allowed advertise.

#

nobody is allowed to

#

recruitment is also not allowed

charred thunder
#

Huh, whats happening here

magic python
#

"Looking for people who—" Yeah advertising.

charred thunder
#

The or is wild 💀

silent junco
#

take a day to read the server rules

#

we can move on now, thanks

zealous garden
#

The set of statements I have left to make about GA is in bijection with a proper subset of itself

twin meadow
#

Hi chat

#

everyone slept

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its raining outside

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AND LIGHT WENT OUT TOI

#

ANYTHING WORSE CAN HAPPEN NOW 😭

cerulean kite
#

hi theree

#

i really want some tips on how to make practicing math a habit every day even when i dont have it in school i still want to become really good at aptitude and solving stuff fast and accurately so some tips would be nice (im in middle school btw)

cerulean oracle
fathom tendon
#

Random question - has anyone been able to sign into mathprograms in the last hour

#

I've been unable to sign in and I'm not receiving login tokens to anywhere in my email inbox

harsh lion
#

Know urself

fathom tendon
#

What

cerulean kite
cerulean oracle
#

Practice every day. I'm not sure what else to say tbh

vale coral
# cerulean kite yeah ik but like how do I make it a routine every day yk

maybe find a way to make math fun? I'm not sure how with with middle school math but once you do you'll naturally get better at it and you won't need a strict routine for it (since it's something you do/think for fun). Maybe try to understand it better, find some applications or talk to people about it. All those might be fun

astral axle
#

I have an Instagram profile called nicemath_ where I make math videos using Manim. Anyone who can help me out there, I’d really appreciate it

frozen patio
#

guys lets be real: 1+1=3

tulip flume
#

@frozen patio Please elaborate that.

frozen patio
#

ok

sand orbit
#

2 = 0

desert rapids
#

Dumb question
$$ \left(1 + \gamma M_1^2 \right) \sqrt{M_2^4 + \frac{2 M_2^2}{\gamma - 1}} = \left(1 + \gamma M_2^2 \right) \sqrt{M_1^4 + \frac{2 M_1^2}{\gamma - 1}} $$
Is there any good way to solve for $M_2$ without doing the huge expansion?

silent junco
#

M_1 = M_2 works sotrue

fathom swallowBOT
#

supersonic

desert rapids
#

I figured it out

#
Solve[(1 + g  M1^2) Sqrt[
    M2^4 + 2  M2^2/(g - 1)] == (1 + g  M2^2) Sqrt[
    M1^4 + 2 M1^2/(g - 1)], M2]
#

Mathematica for the win

still granite
#

Is calc ab low for a senior in hs?

torpid bay
#

For people interested in math, then I generally hear calc ab or bc done in senior year, or maybe calc 3 if your school offers it

#

Some specific schools have programs where you can take a lot more mid to late stage college stuff while in high school, but those are the exception. Alternatively, you can take a summer course or 2 at a college while still in hs if you meet the requirements. But in general for most people I hear them doing calc in college

verbal quest
past heron
#

No.of soln of sinx+cosx=1 in interval [0,2pie]
Ans will be 2 or 3?..
Help me out

silent junco
#

$\sin(x)\cos(x) = 0$

fathom swallowBOT
past heron
#

I m just confused that either should I take 9pie/4 or not..like after solving the equation it will come to sin(x+pie/4) = 1/root2

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And if we equate sinx= 1/root2 in interval 0 to 2pie..then the no of soln will be pie/4,3pie/4 and 9pie/4

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But some said u shouldn't take 9pie/4..

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Means it will lie on the same line as pie/4

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If we look at the quadrant

silent junco
#

the equation has solutions at 0 and pi/2

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and 2pi

past heron
#

Not at 2pie?

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Accha

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Ok ok

silent junco
#

bangali?

past heron
#

Nah..indian (hindu)

silent junco
#

ah i see

past heron
#

Btw how u did it

silent junco
#

squared it, then removed extraneous solutions

#

the candidate solutions are $\frac{k\pi}{2}$ but some of them are due to -1 getting squared to 1

fathom swallowBOT
silent junco
#

so you just plug them into the original equation to see if they work

past heron
#

Yaa..ok ok I did it by harmoinc additional theorem..it's easy

#

Thanks though happy

silent junco
#

np

zealous summit
#

Guys can someone join my Microsoft teams school meeting please, it’s in Bulgarian though.

charred heath
#

Random question, but is anyone good at height comparisons here?

long matrix
#

tall ask

torpid bay
#

@foggy meadow did you find the x^x thing or nah?

dry coral
#

Me and my teacher were actually trying to integrate x^x the other day, we couldn't figure it out, but it was cool to see what problems came up along the way

quasi raven
silent junco
fathom swallowBOT
silent junco
#

$(\sin(x) + \cos(x))^2 = 1 + 2\sin(x)\cos(x)=1$ in this case

fathom swallowBOT
quasi raven
fathom swallowBOT
silent junco
#

indeed

quasi raven
#

I love that formula and that saved my time

neat lintel
quasi raven
neat lintel
rose ridge
#

Natrium

daring totem
#

Guys I have a question. How can someone study Einstein's special theory of relativity without even knowing real analysis or even basic calculus

#

One guy I know claims that

latent edge
snow ice
daring totem
#

Bro what happened @snow ice

snow ice
sharp portal
#

Sorry, to intrude but does anyone have book recommendation or resources for self studying physics?

viral oracle
hexed tangle
viral oracle
latent edge
smoky turret
#

do u know alzebra and calculas?

fiery stump
#

no idk alzebra

rich quail
loud tinsel
#

yo

shell locust
verbal steppe
#

hii

cyan karma
#

Cloudflare saying they have detected unusual traffic from my network when accessing an article though it's just me alone at home and it's the first time I open a researchgate article today looooool opencry opencry

tall escarp
#

how long does it take to learn the DI method?

magic python
#

Learning what it is is simple iirc, but learning when to use it may take longer

tall escarp
#

im in hs so i gotta use it for IBP that includes cyclical integration

magic python
#

You might be able to learn it in a month or so (Probably an exaggeration, it's been a while since I've messed with it)

wraith magnet
tall escarp
#

woahhh thats a long time

#

what makes it take so long?

magic python
#

Probably could in a week tbh

#

It all depends on how much exercises you do

#

Practice is really good if you want to be able to spot when you use it

#

You could probably learn the basics in a day or two tho

tall escarp
#

its applicable everywhere where IBP can be done right

magic python
#

DI is IBP

#

It's just formatted easier to understand

#

iirc

#

Idk you could probably do it in a week, maybe even less

#

Considering you seem to know calc decently enough already

#

iirc you can find lots of videos explaining it on YouTube, most of the time would probably be getting used to noticing when to use it, that comes from practice

idle tiger
#

But if you don't have a good grasp of the math it'll be hard to derive the Lorentz equations and understand it precisely

placid shadow
#

a*b=c, can you subtract b from both sides?

cyan karma
wraith magnet
#

bru

placid shadow
#

What?

wraith magnet
placid shadow
wraith magnet
placid shadow
#

Why?

wraith magnet
placid shadow
rose lance
loud herald
#

Can someone help me with 24=4 x p ??

rose lance
#

Sry I may be a little late

placid shadow
quasi jettyBOT
bronze rock
#

if the whole thing about HCP is that any complex conjugated amplitude based on direction is changed but only reflected as a mirror image then why do they remain pointing the same direction but are still not topologically equivalent? if they are mirroed then surely they are?

#

cant they be deformed to match regardless if there is a different start

faint light
pastel needle
#

Drink vending machines intentionally drop it forcefully so that your drink explodes and you have to get a new one

daring totem
idle tiger
#

However, you need to know some algebra for sure (for example to calculate the lorentz transformation), and some geometry for example the Pythagorean theorem for light clock calculations

drifting flower
#

Hey guys, I want to get into college to become an apprentice. Thing is I struggle a lot with math and have a learning disability. A lot of these apprenticeship trades require lots of math or little math. Could anyone give me some advice?

gentle birch
#

this might seem as generic advice but it's what works for a lot of people
idk much about any learning disabilities though so sorry about that, but what's tried and tested is worth a shot

drifting flower
# gentle birch take your time with the concepts and practice a lot

Okay, would you think getting a tutor would help? I mean they'd have to be patient with me and I learn differently I mean everyone does, and I don't know much about my learning disability I'm diagnosed with it and I know one of the stronger things I struggle with is math so it kinda brings down my hopes for making the decision to go to college, I didn't do bad in school I averaged 70s, my dad says he would pay for it but I'd have to be really committed so there's a lot of pressure.

hallow glacier
#

hi

gentle birch
#

if that doesn't work out feel free to get a tutor

neat lintel
drifting flower
#

@gentle birch what's the best way/method to learn division? I can't do division whatsoever

gentle birch
#

could also watch a youtube video

drifting flower
#

True

gentle birch
#

start from basics like

#

40/10

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20/2

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then go to stuff like 528/13

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remember that division is just repeated subtraction

drifting flower
gentle birch
#

so you have

#

40 - 10 = 30, that's 1

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then 30 - 10 = 20, that's 2

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20 - 10 = 10, that's 3

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10 - 10 = 0, that's 4

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can you do 0 - 10? nope

#

so we have 40/10 = 4 with remainder 0

gentle birch
drifting flower
drifting flower
#

But 20÷2 what would it equal

gentle birch
#

yeah

#

10

drifting flower
#

Okay so basically

gentle birch
drifting flower
#

Ohhh okok

#

So any division problem you subtract it till you can't and the number of times it can be subtracted till 0 is the answer?

#

Like the answer is whatever

gentle birch
#

but that's one way to do it

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that's basically the idea of what division actually is

drifting flower
#

What are the other ways I've got my notebook open right now

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But I need it to be easy

gentle birch
#

you can look up long division on youtube right now

drifting flower
#

Okay thank you

zealous garden
#

if you think about it, modulus is repeated subtraction

#

5 % 3 = 2

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15 % 2 = 1

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repeatedly subtract until doing so again would yield a negative number

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division tells you how many times you could repeat that subtraction, but is itself not the repeated subtraction

#

interestingly, you could also look at mod as the canonical projection of the quotient by the ideal generated by the second argument

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so div is divide the number, mod is divide the space

#

I think that's cool

cold needle
#

?

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What if i put in a negative number in the left argument of %

blazing raft
cold needle
#

ohh ok i see

#

I will avoid that then

blazing raft
#

thank you

cold needle
#

👍

agile fiber
#

you subtract the second argument a negative amount of times

tawny cosmos
#

6 7

random tangle
#

does anyone know of a method to solving a bernoulli question faster?

tulip wren
#

just master your current method

true fox
#

Anyone here a expert at pre calc? Need some help

agile fiber
#

can you please not spam the same message in three channels

round abyss
#

dude just write the help channel post

#

check #precalculus probably. you get faster help from asking any questions you have directly

magic python
#

<@&268886789983436800> spamming too

silent junco
#

how did they even spam that i already timed them out

magic python
#

They sent it again so idk

silent junco
#

oh wait this is discussion 2

magic python
#

I just say it's spam if it's copy pasted to more than one channel

silent junco
#

nvm

silent junco
magic python
#

Kk

silent junco
#

i just thought they sent it after i timed them out

magic python
#

Ah kk

mint patio
#

me trying to look for engineering stuff:

#

google:

#

maybe this belonged in chill sorry lol

ripe dirge
#

I am definitely buckling under pressure

#

Funny how I chose this major by my own volition and I am struggling with it

#

Definitely has to do with time management

jagged forge
#

math major?

ripe dirge
#

Yes

gritty heath
rapid scaffold
#

patty cake patty cake with no hands

ripe dirge
#

My first year was a disaster, thanks to numerous health issues

crisp kindle
#

I hope this channel is kinder to mee

latent leaf
#

Sup

half skiff
#

sky

proper umbra
#

can any one say some importent properties of hyperbola

crystal cave
#

how to get motivated quick

#

quick tell me the secret

#

wrong chat

ripe dirge
inland raft
#

or have someone threaten you

verbal spindle
normal torrent
#

can anyone help me with creating linear equations

barren anchor
#

sup

#
  1. motivation: be anxious
  2. creating arbitrary linear equations is incredibly easy, you've probably been doing it forever (y = mx + b bruh)
austere scaffold
#

how's diff eq. vs multivariable calculus? i've heard different things, like it's easier but more tedious. i know it varies greatly br institution, but im curious about others' experiences

ripe dirge
#

Multivariable calculus is similarly tedious

#

definitely as tedious as Differential Equations

turbid sedge
#

Hi fiscussy 2

magic quiver
#

taking intro to proof-writing before diff eq was a mistake

#

i can no longer compute anything lol

rare summit
#

I know it's quite a while later, but I ended up getting a travel whiteboard that I take with me to lecture each day. It's very useful for communicating concepts to friends, and I can draw pictures that are on the board so I can later replicate them to put in my notes. I'm still a little sad that I can't quite work on the same surface as my peers, but this is good enough most of the time

coral sand
#

0+0=1

frosty zephyr
#

Anyone in university

#

In Malaysia?

pastel blade
viral oracle
last rose
rocky shuttle
last rose
quartz compass
#

does anyone here like flowers?

narrow compass
#

dead chat

neat lintel
worldly horizon
vast wraith
#

guh this seems like a nice article except this typesetting, i hate when they squish things like that blobcry

frosty zephyr
#

U study in malaysia?

viral oracle
#

technically I'm not studying, but I am a Malaysian, yes

frosty zephyr
#

Ohh

#

So ur in school?

viral oracle
#

oops, sorry, didn't see your msg

pure hollow
#

pro

viral oracle
#

NO

pure hollow
viral oracle
#

am nub

pure hollow
viral oracle
#

no lies

#

smh

pure hollow
viral oracle
#

I've been stuck in chp1 of abbott for four months :|

pure hollow
viral oracle
#

am still bad! SCCUTE

pure hollow
true zinc
viral oracle
velvet crypt
viral oracle
limber thunder
#

<@&268886789983436800>

radiant sparrow
radiant sparrow
pure hollow
rocky shuttle
vernal gorge
#

guys i have to pick between lie groups and matrix operations next semester which should i take

torpid bay
velvet dagger
viral oracle
agile sundial
elfin smelt
foggy meadow
turbid sedge
#

Hii

white lichen
rustic mountain
#

Hi

rich quail
#

Hi

unkempt crest
#

hi

bronze pelican
#

Seems like a lazy way to get around the page limit

viral oracle
rustic mountain
viral oracle
#

just for the record, no

zealous garden
#

I can't believe no one pinged me for this banger

inland hornet
#

my bad

#

@zealous garden

true zinc
zealous garden
small dust
stone ferry
viral oracle
stone ferry
#

I see. I'll report this to the council of green, the algorithm must be perfected.

fresh comet
oak leaf
junior turtle
latent edge
junior turtle
digital maple
#

Hello?

true zinc
digital maple
#

@fresh comet can we dm and I tell you about bad discord user who sometimes join to troll server?

dapper garden
main plaza
#

polyhedra though 👀

magic python
#

:3

noble tinsel
#

:3

simple reef
#

no

torpid bay
latent edge
torpid bay
#

oh u here lisayay

#

allright, so I'll define a a sequence A in two parts: 1 is the initial conditions and 2 is the iterated part

#

Let 'a' be a sequence with terms $a_0,a_1...a_k$

fathom swallowBOT
#

Yeatte

torpid bay
#

and let A be the sequence where A_n = a_n for $0\leq n \leq k$

fathom swallowBOT
#

Yeatte
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

torpid bay
#

now let any term greater than k be defined as such

#

or rather, have the bound

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$A_{m+1}\leq A_m + f(\prod_{n=1}^{m}{(1-\frac{1}{A_n})^{-1}})$

fathom swallowBOT
#

Yeatte

latent edge
torpid bay
#

I mean for this to essentially mimic primes and to get the lowest expected prime number, but I realized i didn't know enough about this the thing i set up, so I was wondering a few things about this sorta thing

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a few things i noticed was

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suppose I have A_0 = B_0, and A_1 > B_1

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and suppose the two f's are the same for each, and certain conditions liks a>b implies f(a) > f(b)

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then the entire f term for the A sequence is less than the entire f term for the B sequence,

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so in other words

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A_1 > B_1 implies A_2 - A_1 < B_2 - B_1

#

in a sense balancing it out, maybe? my naiive guess was that any two sequences defined in this manner will have the same growth rate

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or rather, $\lim_{x\to\infty}{\frac{A_x}{B_x}} = 1 \forall A,B$

fathom swallowBOT
#

Yeatte

latent edge
#

no i literally have no idea what you are trying to do

torpid bay
#

oh i think i missed a condition, in the thing above i had A_m+1 <= A_m stuff, but in the growth rate conjecture i want it to be A_m+1 = A_m + f stuff

#

anyway, ill go get an example of what im thinking of

#

the reason, is that when i made this to make a fake prime sequence, it seemed to have the same growth rate as the actual prime sequence

#

so i wanted to use this to bound the real primes

latent edge
#

you seem to be interested in these things a lot huh

#

why not read Apostol's analytic number theory?

torpid bay
torpid bay
latent edge
#

yes

torpid bay
#

huh

#

turns out oeis does have that fake prime sequence in it

#

and i got this link

latent edge
#

many such cases

torpid bay
#

rip i guess i wasnt the first to attempt this method

latent edge
#

i mean it's fine

torpid bay
#

catshrug it means they prob have results on it

#

49 bucks to get a pdf? wot

#

ig ye my only questions were about that sequence thing

#

well, there is one, but i def dont have the prerequisites to understand the answer to it

graceful quiver
latent edge
foggy meadow
torpid bay
#

im beating up bugs rn

foggy meadow
torpid bay
#

silksong

shadow palm
ornate glade
#

MATHEMATICS!!

willow herald
old oak
#

they know what they did

real pagoda
#

yo guys

eager cedar
#

anyone applying to sumac

neat lintel
ripe dirge
#

Hmm

#

seems I will have to drop the idea of passing Real Analysis this semester

#

lemme save my other papers then

wraith rose
#

Hey

unborn patrol
#

Hey! I am fresher. Can anyone give me guidance for maths for learning Machine learning

lunar adder
#

Alguém br!?

inland raft
#

for those interested

lime fractal
#

😭

civic canopy
#

Boi 67 so tuffdevastation

noble tinsel
civic canopy
#

Boi

civic canopy
#

I swear i used to have a boi so tuff jif

#

I have this though

shadow palm
hard oasis
agile fiber
hard oasis
#

The Iwaniec--Kowalski is like a bible, and the Bateman--Diamond is lesser known but very cool

#

Also there's always Keith Conrad's lecture notes on the many topics of ANT

tall pond
latent edge
#

So many number theory propaganda

#

Alex Kontorovich and matplotlib recommending ANT

deft dust
#

Really pretty

brave flare
bronze pelican
royal tangle
#

"Moreover I am of the opinion that Carthage should be destroyed"

noble tinsel
#

carthago delenda est 🗣️

vivid halo
#

I'm tired of waiting we need to accellerate

foggy meadow
#

@torpid bay So, silly math we did does cool things with path integrations. Also, Sum and Products (SP) seem impossible to escape from for path based stuff.

torpid bay
#

hm

#

would taking different paths for a path integral yeild different inverses? and so a multivalued inverse can be done that way ig

foggy meadow
#

Basically for calculus over C the input function must be g(x)^{2} for it to be the identity, and the function g(x) must be \int^{\infty}_{\infty} g(z)^{2} dz < \infty. Which looks a lot like some properties of physics.

torpid bay
#

ah, schwartz function iirc

foggy meadow
foggy meadow
#

Like it'd be pretty simple to do I think.

#

I'm just not sure if one needs to fractional integrate the path or like derivate the path at all. More so this is just interesting rather than useful feeling to me.

torpid bay
foggy meadow
#

Besides just giving intuition for basic lemmas in quantum physics. I don't feel like it offers much, but it's neat to be able to do.

foggy meadow
torpid bay
#

well

#

I wanted an upper bound for primes

#

and i based it off of factorization

#

heere's the basic idea

#

if i have two consecutive numbers, then at least one of them is not divisible by 2

#

therefore

#

either 2+1 or 2+2 is the next prime

#

however, what if i have the primes 2 and 3? then wahts the chance a number is divisible by neither of them?

#

$(1-\frac{1}{2})(1-\frac{1}{3})$

fathom swallowBOT
#

Yeatte

torpid bay
#

which is just (1/2)(2/3) = 1/3

#

so i take x * (1/3)= 1 where x is to be the number of consecutive numbers to check at most

#

which if actually calculated, checks out

#

so x = 3

#

therefore 3 + 1, 3+2, or 3+3 is prime

#

and i continue

#

(1-1/2)(1-1/3)(1-1/5) = (1/3)(4/5), so x = 15/4 = 3.75, but i round x up to 4

#

so 5 +1,5+2,5+3,5+4 at least one is prime

#

and we continue

#

what if we take the worst case scenario where the next predicted prime is that p + x value?

#

then instead when we start at 2, we get a certain sqeuence

#

2,4,7,11,15,19...

#

if I am to write this out using notation it is

#

$p_{k+1} \leq p_k + \ceil{\prod_{n=1}^{k}{(1-\frac{1}{p_n})^{-1}}}$

fathom swallowBOT
#

Yeatte

torpid bay
#

but in this case we just set it equal for A_k+1 = A_k + ceil(stuff)

#

so the question is, how bad of an approximation is it?

#

if we label this sequence of fake primes as A_k

#

then from desmos testing

#

$\lim_{k\to\infty}{\frac{A_k}{p_k}} = 1$

fathom swallowBOT
#

Yeatte

torpid bay
#

so its actually pretty good

foggy meadow
torpid bay
#

uh

#

wait

#

thats wierd

foggy meadow
#

P U {16}

torpid bay
#

16,49

#

seems to be squares

foggy meadow
#

How did you calculate P? I'm assuming it means primes, btw.

torpid bay
#

essentailly, compare number n against primes via modulo

#

if no factors, then add to list

foggy meadow
torpid bay
#

ugh

#

lets just make 16 prime or smthn

#

huh

#

for some reason it listed 16 and 49 in it as well

foggy meadow
#

Just take that then come back.

torpid bay
#

I wanted an efficient algorithm that spits out primes at will :\

foggy meadow
#

Gotta make sure prime times prime isn't like (x*x = p or p mod x)\

torpid bay
#

oh crap

#

for the prime numbers, i didnt actually reset the prime i was using against n

#

wait, why would that affect this then?

foggy meadow
#

Idk what is 7*7 mod 7?

torpid bay
#

0

foggy meadow
#

Yeah so, the off chance a number is p*p*... may not be caught by the seive?

torpid bay
#

7^k mod 7 = 0 for positive integer k, so it should be fine i think

#

for some reason, it just isn't checking 16/2

#

like

foggy meadow
#

Do you reset n = 3?

#

Then it'll never mod 2?

torpid bay
#

its just not checking 2 for any of them

#

wtf

#

then why is 49 failing as well

vivid halo
torpid bay
#

oh

#

did i hallucinate 49

#

its not here anymore

foggy meadow
#

16 is.

#

and 12?

torpid bay
#

12 is divisible by 3 so it gets checked out

#

but then why not 8?

foggy meadow
torpid bay
#

wait

#

8 gets checked by 2

foggy meadow
torpid bay
#

ye, but the checker value starts at 2

foggy meadow
#

???

torpid bay
#

3 is the initial number wher i ask "check dis" and p[0] should be the first number it uses in the modulo against it

foggy meadow
#

just add in the if statement if( n mod 2 == 1 && ...) and call it a day?

torpid bay
#

but for 8 it actaully does check 2, but for 9 it doesnt

#

wait

#

hold on

#

this might be stupid

#

no nvm i dont get it

#

yeah its just not running that first prime p[0] sometimes

#

wait

#

hold on

gritty heath
# torpid bay

int p[] = new int[5000];

void setup() {
p[0] = 2;
p[1] = 3;
int ptr = 2;
for (int n = 5; ptr < 5000; n += 2) {
for (int k=1; k < ptr; k++) {
if (n % p[k] == 0) {
p[ptr] = n;
ptr++;
break;
}
}
}
}

torpid bay
#

yeah

#

that'll work as well

#

maybe its because i'm trying to change b while its in it's own for iteration?

gritty heath
#

maybe

#

that makes it hard to reason at least, i try to not modify the looping variable

torpid bay
#

oh hold on

#

i see what's going on

#

aha

#

yeah it is

#

so what;s happening is if its not prime, then i set b = 0, but at the end of the for statement, it increases by 1, so i end up cheking all primes greater than 2

#

and skipping it

gritty heath
#

another way is to recall that the 5000th prime is larger than 5000(ln 5000 + ln ln 5000 - 1) ~ 48926
make an array of size 48230 for safety, and do a sieve of eratosthenes

torpid bay
#

ok yeah that fixed it

#

b = -1 now

#

fun little problem lel

#

im glad 49 turned out to not exist

foggy meadow
torpid bay
#

pretty much the same

gritty heath
torpid bay
#

S = pseudo primes via a certain recurrence relation, P = true primes

young dagger
#

Guys, if anyone is from the quant sector, can they please dm me? I need some help 🙂

foggy meadow
torpid bay
#

2,3,5 etc

young dagger
young dagger
foggy meadow
young dagger
#

That was settled much before, but true prime is still used to refer to the set of prime numbers such that x > 1

torpid bay
#

one defined by the recurrence relation: $S_{k+1} = S_k + \ceil{\prod_{n=1}^{k}{(1-\frac{1}{p_n})^{-1}}}$

fathom swallowBOT
#

Yeatte

torpid bay
#

tho this does lead to the generalization of

#

$A_{k+1} \leq A_k + f({\prod_{n=1}^{k}{(1-\frac{1}{p_n})^{-1}})$

fathom swallowBOT
#

Yeatte
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

young dagger
#

Isn't this a formula that builds a sequence using the usual prime numbers to study their overall distribution?

torpid bay
#

im pretty sure a true prime would satisfy this

#

the less than or equal one

young dagger
#

Can you tell me the problem? I am lost

torpid bay
#

take 2 consecustive numbers, at least one of them is coprime to 2

#

at least and exactly one of them to be precise

#

if i take 3 consecutive numbers, then 2 of them are coprime to 2

#

but then one of those 2 is coprime to 2

#

so if i want a number coprime to 2 and 3, then i need just 3 consecutive numbers and itll be in there

#

so i take 3, and so the next prime after 3 is either 3+1,3+2, or 3+3

#

going back, the next prime after 2 is either 2+1 or 2+2

young dagger
#

-# Might be a miscommunication, but I meant the what the question that you were trying to solve was, but please, if im wrong, go on.

torpid bay
#

oh, im just trying to iteratively find an upper bound for primes

#

using iteration

young dagger
torpid bay
#

there is an assumption ye

young dagger
#

Among any
𝑘
consecutive numbers, some will be coprime to a given set of primes, but being coprime to small primes does not guarantee being prime, only that the number avoids those factors.

torpid bay
#

im not checking any random k numbers tho

#

just the k numbers right above the primes we already have

#

so no room for any extra possible primes betwene the known primes and the possible set of k numbers we're checking

young dagger
#

please wait

#

\textbf{Claim.}
Let $p_k$ be the $k$-th prime. There is no guarantee that the interval
[
p_k+1,, p_k+2,, \dots,, p_k+k
]
contains a prime.

\textbf{Proof.}
Fix $k \ge 1$. Choose $k$ distinct primes
$q_1, q_2, \dots, q_k$ such that $q_i > p_k$ for all $i$.

We know that by the Chinese Remainder Theorem, there exists an integer $N$ such that
[
N \equiv -i \pmod{q_i} \quad \text{for } i=1,2,\dots,k.
]

Then for each $i$,
[
N+i \equiv 0 \pmod{q_i},
]
so $N+i$ is composite.

Thus the $k$ consecutive integers
[
N+1, N+2, \dots, N+k
]
are all composite.

Let $p_k$ be the largest prime less than $N$. Then the interval
[
{p_k+1, \dots, p_k+k}
]
contains no prime.
\qed

fathom swallowBOT
#

diddy_lovesme

young dagger
#

@torpid bay

torpid bay
#

the interval isn't based on k

#

above the p_k'th prime

young dagger
#

oh...

#

Can you please give me the formal question again then?

#

Sorry but english isnt my mother language so I have dificulties

#

I usually do math in my language so theres a boundary

torpid bay
#

if I have the first k primes, what is the most number of consectuvies numbers above p_k that one has to check to get a new prime? naiively a basic upper bound would be 2^k, tho instead i use actual factorization to cut that down

young dagger
#

from what i understand, your intuition is each known prime removes residue classes, so after finitely many steps something must survive

torpid bay
#

(1-1/2)(1-1/3)(1-1/5)...(1-1/p_k) * x => 1, smallest integer x is the new upper bound of number of consecutive numbers to check above p_k, being the numbers p_k + 1, p_k + 2.. p_k + x

young dagger
#

Am I correct?

torpid bay
#

i havent heard of a residue class

#

but if it is what it sounds like, then yes

young dagger
fathom swallowBOT
#

diddy_lovesme

young dagger
#

so is it still a yes?

torpid bay
#

removing the residue classes of 0 with respect to each prime modulo yeah

young dagger
#

Oh then I guess I see where you went wrong

#

please wait

#

The error was:

\textbf{Error.}
The argument incorrectly replaces the statement
[
\text{expected number of survivors } \ge 1'' \] with \[ \text{a prime must exist.''}
]
The product only controls divisibility by primes $\le p_k$, not
compositeness by larger primes.

fathom swallowBOT
#

diddy_lovesme

young dagger
#

Formally,

torpid bay
#

any larger prime would be a new prime

#

being the new one added to the list

young dagger
#

but it still doesnt account for your logical gap

torpid bay
#

no?

young dagger
#

\begin{theorem}
Let $p_k$ be the $k$-th prime.
The fact that every prime divisor larger than $p_k$ is a new prime does not
imply that an integer coprime to all primes $\le p_k$ is itself prime.
\end{theorem}

\begin{proof}
Suppose $n$ satisfies
[
\gcd(n, p_1 p_2 \cdots p_k) = 1.
]
Then no prime $p \le p_k$ divides $n$. Consequently, every prime divisor of
$n$ is strictly larger than $p_k$, and hence is a new prime.

However, this does not imply that $n$ has only one prime divisor.
Indeed, let
[
n = p_{k+1} \cdot p_{k+2}.
]
Then $n$ is composite, yet all of its prime divisors exceed $p_k$.
Thus $n$ is coprime to all primes $\le p_k$ but is not prime.

Therefore, the implication
[
\gcd(n, p_1 p_2 \cdots p_k)=1 ;\Longrightarrow; n \text{ is prime}
]
is false.
\end{proof}

fathom swallowBOT
#

diddy_lovesme
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

foggy meadow
#

It's really neat!

torpid bay
#

I'm not saying that an number coprime to all p: 2 <= p <= p_k is necessarily a prime, what im saying is that within the interval p_k... p_k + x, if there was a number corpime to p_k etc, then it would either a: be a new prime, or b: be a composite that is divisible by a new prime that would still be in that interval from p_k to p_k + x

#

and this is with the condition that our p_1 ... p_k list is entirely complete up to the point of p_k at that point

young dagger
# torpid bay I'm not saying that an number coprime to all p: 2 <= p <= p_k is necessarily a p...

\begin{theorem}
Let $p_k$ be the $k$-th prime and let $x \ge 1$.
The existence of an integer
[
n \in (p_k,; p_k+x]
\quad\text{with}\quad
\gcd(n, p_1p_2\cdots p_k)=1
]
does \emph{not} imply that there exists a new prime in the interval
$(p_k,; p_k+x]$.
\end{theorem}

\begin{proof}
Assume, for contradiction, that the existence of such an $n$ forces a new
prime $q$ with
[
p_k < q \le p_k+x.
]

Choose a prime $Q$ such that
[
Q > p_k + x.
]
(Such a prime exists by Euclid’s theorem.)

Let
[
n := Q^2.
]

Then the following hold:
\begin{enumerate}
\item $n$ is composite.
\item Every prime divisor of $n$ equals $Q$, so all prime divisors of $n$
satisfy $Q > p_k$.
\item Hence
[
\gcd(n, p_1p_2\cdots p_k)=1.
]
\end{enumerate}

Thus $n$ is coprime to all primes $\le p_k$ and is a valid “survivor” of the
small-prime sieve.

However, $n$ has no prime divisor $q$ with
[
p_k < q \le p_k+x,
]
since its only prime divisor is $Q > p_k+x$.

Therefore, the existence of such an $n$ does not force the existence of a new
prime in the interval $(p_k,; p_k+x]$, contradicting the assumption.

Hence the claim is false.
\end{proof}

fathom swallowBOT
#

diddy_lovesme
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

young dagger
#

I dont know mate I might be heavily misunderstanding

#

Sorry if I am wrong in this regard

#

please, do consider better help than me if I dont seem to be understanding what you mean

torpid bay
#

if Q > p_k + x, then its entirely outside the interval we care about

young dagger
young dagger
#

Wait ill really rack my brain

torpid bay
#

oh x is a specific number btw

#

not just any x => 1

young dagger
#

Ohhhhh

#

OHHHH

#

That makes much more sense now

#

😭

#

sorry for not understanding your question

torpid bay
#

nah its fine catthumbsup

#

specifically i chose x large enough to make sure that 100% there be a comprime within the interval right above p_k

young dagger
#

can you give me your full statements will all restraints ill need to consider? I am very bad at keeping things in mind. I need it all laid out for me, if you dont mind

torpid bay
#

all irght

young dagger
#

and the method (formula) you use now

torpid bay
#

Given the set of primes ${2,3...p_k}$(complete set from 2 to $p_k$, no gaps), there will always exist at least one prime within the interval of consecutive numbers ${p_k+1...p_k+x}$ that is coprime to all prime in that set, and thus is either a new prime, or is a composite divisible by a new prime larger than $p_k$ and is also thus in the interval. $x \coloneq \ceil{\prod_{n=1}^{k}{(1-\frac{1}{p_n})^{-1}}$

fathom swallowBOT
#

Yeatte
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

young dagger
#

Given the set of primes
[
{2, 3, \dots, p_k} \quad (\text{the complete set of primes from } 2 \text{ to } p_k),
]
there will always exist at least one number in the interval
[
{p_k+1, p_k+2, \dots, p_k+x}
]
that is coprime to all primes in that set. Such a number is either:
\begin{enumerate}
\item a new prime, or
\item a composite divisible by a prime larger than (p_k), which must also lie within the interval.
\end{enumerate}
Here,
[
x \coloneqq \Bigg\lceil \prod_{n=1}^{k} \Big(1 - \frac{1}{p_n}\Big)^{-1} \Bigg\rceil.
]

fathom swallowBOT
#

diddy_lovesme

young dagger
#

Any constraints

#

?

torpid bay
#

unless im forgetting anything, that's all

young dagger
#

okkkk

torpid bay
#

should give the minimal x that still guarantees a coprime within interval

young dagger
#

so you want to prove this claim rgiht?

torpid bay
#

yep

young dagger
#

hmm alr

#

Ill work on it too

#

wait kay

torpid bay
young dagger
#

can you check it for the set {2,3,5,7}?

torpid bay
#

then x = 4, and so we check 7+1, 7+2, 7+3, 7+4

young dagger
torpid bay
#

7+4 = 11

young dagger
#

oh there exists at least one?

torpid bay
#

yep

young dagger
#

Im retarted

tribal talon
#

Integral from 0 to pi over 2 to ( x * cos (x) - sin (x) ) / (x^2 + sin^2 (x) )

torpid bay
#

23 is also interesting

#

first gap of 6 and works a ok

#

quite trivially, the x will increase without bound

#

that 8 to 11 interval is probably the closest it has to failing

young dagger
#

I have a proof i guess but it is very hand waby

#

wavy*

torpid bay
#

ooo 113 to 127 gap is also quite close

#

tho actually, there does become this problem that i thought i might into

#

where it actuall fails

#

so yeah 113 to 127 fils

#

and im pretty sure i know why

young dagger
#

I conjecture the statement is likely TRUE, but a rigorous proof is beyond the scope of elementary number theory

#

\begin{theorem}
Let
[
S_k = {p_1, p_2, \dots, p_k}
]
be the first $k$ primes, and define
[
x = \left\lceil \prod_{i=1}^{k} \left(1 - \frac{1}{p_i}\right)^{-1} \right\rceil.
]
Then there exists at least one integer
[
n \in [p_k+1, p_k+x]
]
such that
[
\gcd(n, p_1 p_2 \cdots p_k) = 1.
]
\end{theorem}

\begin{proof}
Let
[
I = [p_k+1, p_k+x]
]
and for each $i = 1, \dots, k$ define
[
A_i = { n \in I : p_i \mid n }.
]
We want to show
[
|I \setminus \bigcup_{i=1}^k A_i| \geq 1.
]

By the inclusion-exclusion principle:
[
|I \setminus \bigcup_{i=1}^k A_i| = x - \left| \bigcup_{i=1}^k A_i \right|.
]

Using the Möbius function $\mu$:
[
|I \setminus \bigcup_{i=1}^k A_i| = \sum_{d \mid N} \mu(d)
\left( \left\lfloor \frac{p_k+x}{d} \right\rfloor - \left\lfloor \frac{p_k}{d} \right\rfloor \right),
]
where $N = \prod_{i=1}^k p_i$.

Write
[
\left\lfloor \frac{p_k+x}{d} \right\rfloor - \left\lfloor \frac{p_k}{d} \right\rfloor = \frac{x}{d} + \epsilon_d, \quad |\epsilon_d| \le 1.
]

Thus
[
|I \setminus \bigcup_{i=1}^k A_i| = x \sum_{d \mid N} \frac{\mu(d)}{d} + \sum_{d \mid N} \mu(d) \epsilon_d.
]

Observe that
[
\sum_{d \mid N} \frac{\mu(d)}{d} = \prod_{i=1}^k \left( 1 - \frac{1}{p_i} \right) = \frac{1}{x - \epsilon_x}, \quad 0 \le \epsilon_x < 1.
]

Also,
[
\left| \sum_{d \mid N} \mu(d) \epsilon_d \right| \le \sum_{d \mid N} |\mu(d)| = 2^k.
]

Therefore,
[
|I \setminus \bigcup_{i=1}^k A_i| = \frac{x}{x - \epsilon_x} + O(2^k).
]

Since the error term $O(2^k)$ dominates for large $k$, this bound is insufficient to guarantee $|I \setminus \bigcup_{i=1}^k A_i| \ge 1$ rigorously.

Nonetheless, for small $k$, the main term exceeds 1 and the bound $x$ ensures that at least one integer in $I$ is coprime to all $p_i$.
\end{proof}

fathom swallowBOT
#

diddy_lovesme
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

young dagger
#

before i go to eat, can you run a test for k = 30?

torpid bay
#

i think it fails for 113

young dagger
#

def sieve(limit):
    is_prime = [True] * (limit + 1)
    is_prime[0] = is_prime[1] = False
    for i in range(2, int(math.sqrt(limit)) + 1):
        if is_prime[i]:
            for j in range(i*i, limit + 1, i):
                is_prime[j] = False
    return [i for i in range(2, limit + 1) if is_prime[i]]

primes = sieve(200)[:30]  # First 30 primes
product = 1.0
for p in primes:
    product *= p / (p - 1)

x = math.ceil(product)
print(f"x = {x}")

# Check interval [114, 122]
for n in range(114, 123):
    factors = []
    temp = n
    for p in primes:
        if temp % p == 0:
            factors.append(p)
            while temp % p == 0:
                temp //= p
    print(f"{n} has factors in S_30: {factors}")
#

it failed this but idk if i did smth bad in code

torpid bay
#

the x for 113 is about 8.7, but the gap from 113 to 127 is 14

#

and i think the propblem is multiplying the fractions together

frail juniper
#

Hey guys

#

I have a question regarding cantor’s theorem

#

If a set led to a set of all sets e.g. the set necessarily N turned to a self-referential set of all sets, would that mean the set necessarily N is contradictory not only that it’s improperly formatted?

#

e.g., a necessary disjunction of all insufficient explanations Z where Z in itself is an explanation and is found in itself and every other set L is found in Z and is an insufficient explanation.

torpid bay
#

hm

#

yeah it must be the fractions

#

then the true x must be between $\ceil{\prod_{n=1}^{k}{(1-\frac{1}{p_n})^{-1}}}$ and $\prod_{n=1}^{k}{\ceil{(1-\frac{1}{p_n})^{-1}}}$

fathom swallowBOT
#

Yeatte

torpid bay
#

the latter just equals 2^k

#

the question is, whats the minimal number of primes where i need to switch the inside to ceil and keep the rest having the ceil on the outside

#

actually, why does it fail?

stiff fable
#

halo

torpid bay
#

hm

#

suppose i take x consectutive numbers

young dagger
#

I have my own homework now

#

but a very fun problem man

torpid bay
#

then floor(x/2) is minimal number of numbers divisible by 2, same for floor(x/p) for prime p, the thing is, if i do floor(floor(x/2)/3) then im that gets the true value for number of minimal primes in that interval, but floor(x/6) does not

young dagger
#

been a long time since i had to use python for proving

torpid bay
#

yeah, x was a little lowballed because i didnt account for that

#

oop

#

a better example

#

yeah, this fracion error occurs much more in higher numbers

#

the true x should be higher because these are lower

#

mm

#

well, onthe other hand

#

kinda feels like p_k <= p_(k+1) <= 2p_k is in sight

#

eh

sonic orbit
young dagger
#

\documentclass{article}
\usepackage{amsmath, amssymb}

\begin{document}

\section*{Backpropagation Mathematical Model}

\subsection*{1. Forward Pass}

For a network with $L$ layers:

[
a^{[0]} = x
]

[
z^{[l]} = W^{[l]} a^{[l-1]} + b^{[l]}, \quad l = 1, 2, ..., L
]

[
a^{[l]} = \sigma^{[l]}(z^{[l]}), \quad l = 1, 2, ..., L
]

where
\begin{itemize}
\item $W^{[l]}$ is the weight matrix of layer $l$
\item $b^{[l]}$ is the bias vector of layer $l$
\item $\sigma^{[l]}$ is the activation function
\end{itemize}

The final output is:
[
\hat{y} = a^{[L]}
]

\subsection*{2. Loss Function}

Let the loss function be $L(\hat{y}, y)$, e.g.:
[
L = \frac{1}{2} (\hat{y} - y)^2 \quad \text{(MSE)}
]
or
[
L = -\sum y \log(\hat{y}) \quad \text{(cross-entropy)}
]

\subsection*{3. Backward Pass – Error Terms}

Define the error term $\delta^{[l]}$:

[
\delta^{[l]} = \frac{\partial L}{\partial z^{[l]}} = \frac{\partial L}{\partial a^{[l]}} \odot \sigma'^{[l]}(z^{[l]})
]

\textbf{Output layer:}
[
\delta^{[L]} = \nabla_{a^{[L]}} L \odot \sigma'^{[L]}(z^{[L]})
]

\textbf{Hidden layers ($l = L-1, ..., 1$):}
[
\delta^{[l]} = (W^{[l+1]})^T \delta^{[l+1]} \odot \sigma'^{[l]}(z^{[l]})
]

\subsection*{4. Gradients of Weights and Biases}

[
\frac{\partial L}{\partial W^{[l]}} = \delta^{[l]} (a^{[l-1]})^T
]

[
\frac{\partial L}{\partial b^{[l]}} = \delta^{[l]}
]

\subsection*{5. Weight Update (Gradient Descent)}

[
W^{[l]} \gets W^{[l]} - \eta \frac{\partial L}{\partial W^{[l]}}
]

[
b^{[l]} \gets b^{[l]} - \eta \frac{\partial L}{\partial b^{[l]}}
]

where $\eta$ is the learning rate.

\end{document}

fathom swallowBOT
#

diddy_lovesme
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young dagger
#

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\section*{Why We Take the Derivative of the Sigmoid Function}

The sigmoid function is defined as:
[
\sigma(x) = \frac{1}{1 + e^{-x}}
]

During backpropagation, we want to update the weights of a neural network to reduce the loss. To do this, we need to know how the loss changes with respect to each weight. Using the chain rule, for a weight $w$ connected to a neuron, we have:

[
\frac{\partial L}{\partial w} = \frac{\partial L}{\partial y_{\text{hat}}} \cdot \frac{\partial y_{\text{hat}}}{\partial a} \cdot \frac{\partial a}{\partial z} \cdot \frac{\partial z}{\partial w}
]

Here:
\begin{itemize}
\item $z = w \cdot x + b$ is the input to the neuron,
\item $a = \sigma(z)$ is the output (activation) of the neuron,
\item $y_{\text{hat}}$ is the output of the network,
\item $L$ is the loss function.
\end{itemize}

The term $\frac{\partial a}{\partial z}$ is the derivative of the sigmoid function:
[
\sigma'(z) = \sigma(z) (1 - \sigma(z))
]

\subsection*{Intuition}

\begin{itemize}
\item The derivative measures \textbf{how sensitive the neuron's output is to changes in its input}.
\item If the output $a$ is near 0 or 1, the derivative is small, meaning the neuron is \textbf{already confident}, so its weight should change less.
\item If $a$ is around 0.5, the derivative is larger, meaning small changes in input affect the output more, so the weight should adjust more.
\item Multiplying the error by $\sigma'(z)$ correctly scales the weight update for each neuron.
\end{itemize}

\end{document}

fathom swallowBOT
#

diddy_lovesme
Compile Error! Click the errors reaction for more information.
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humble jacinth
#

@molten grove is it ok for me to dm you? (to talk about the thing in your bio)

eager knot
#

Is there slow mode here

#

Omg

#

No soowmofe

#

Yay

#

Slow mode

last rose
#

what the blud

old oak
mint patio
#

Mannn

#

be feather, do idiot things that'll hurt your career

#

get stressed when you potentially have to face the consequences of said idiot things

#

Professor I want to do research with is ASKING ME FOR MY TRANSCRIPT and it DOES NOT LOOK THE BEST 😐

#

He likes me but still

#

😔

eager knot
#

A

eager knot
gleaming kite
#

heyyy does anybody by chacne have studydrive premium?

keen berry
#

we all need to blurt out thinking

#

especially in mathematical situations where instant resolve is needed

#

slowmode just delays things

#

and to be honest only profound mental deficiency would cause someone to spam here

old oak
old oak
keen berry
old oak
#

I'm mostly

#

in favour of slow mode

#

because

#

a lot of people

#

type

#

like this

haughty lion
#

And then someone sends a wall of text halway through and following the convo becomes impossible

errant zenith
molten grove
#

I’m trying to get it fixed

errant zenith
molten grove
#

Then why say it

errant zenith
#

idk its just funny and unusual

#

also it says spammer not scammer

#

and ur status says scammer

mental vector
#

How to use foundations channel

#

Please

young elbow
#

is 1/infinity in an rng still possible

old oak
#

What does "possible" mean here? And what does "in an rng" mean here?

dire sandal
vast wraith
dire sandal
#

tho ur still right ofc

tame egret
#

<@&268886789983436800> is this allowed hmmcatfone

tame egret
torpid bay
#

indeed, PDA in a starbucks is not allowed

vast bloom
tranquil kayak
latent edge
#

what about 67?

#

I know the quadratic field with discriminant d=-67 is an example of a non euclidean ring of integer

main plaza
latent edge
young dagger
#

oh shi 😭

fervent kite
#

This app keeps sending me side quests instead of the main story.

normal orchid
#

most game have more side quest than main story ¯_(ツ)_/¯

eager cedar
#

GUYS HAS ANYONE QUALIFIED RMO?

keen berry
#

<@&268886789983436800> was my postgrad refused or did i accidentally select undergrad

bright condor
keen berry
#

okay

#

im new, where is modmail

hard oasis
#

@polar panther

#

Dm that bot

zealous birch
#

I'm preparing for ioqm

#

Finally found someone

ripe dirge
#

Hmm

#

I wonder how my fellow math lovers cope with crippling depression

#

I am unable to focus

ripe dirge
#

hmm

#

can't afford it

#

I guess I will coast through it somehow

tranquil kayak
#

Smh

sharp mulch
ripe dirge
#

You are right

#

I need a break

#

I am tired

azure rune
#

the number 2

#

secret ,

#

One marriage had generated the world around us

#

from who they made natural numbers

#

the number 2 for couples .male and female in humans ,plants ,animals .

charred wigeon
#

Yoo

reef dew
#

Yoyoyoyo

shadow palm
#

@azure rune @charred wigeon
Hi, new nerds! welcome to #discussion, home of general/non-mathematical discussion. We also have #math-discussion for more mathematically-oriented discussion

azure rune
pastel blade
coarse sierra
#

Hi

foggy meadow
#

@vivid halo Before the chat got server political. I assume that Artin Stacks add new properties that Orbifolds don't have, due to their continuity?

vivid halo
#

like here is something funny this allows: a quotient X/G should have dimension dim(X/G)=dim(X)-dim(G), and this dimension will be negative as soon as dim(G)>dim(X)

#

finite groups have dimension 0 so no negative dimensional examples arise for Deligne-Mumford stacks, but plenty of more general Artin stacks are like this

#

maybe the most basic example is BG=pt/G

foggy meadow
#

Dimension like literal dimension or?

vivid halo
#

any good definition of dimension will have to be like this yes

#

it's either that or you just give up being able to define dimension for stacks which is the worse alternative

foggy meadow
#

R^{-1} sounds wild.

vivid halo
#

it's not quite like that though

#

for stacks individual points sort of remember their "internal symmetries" and if this internal group of symmetries has positive dimension then this should modify the overall dimension accordingly

#

when dim(G)<dim(X) this is a very classical thing that people are comfortable with

foggy meadow
#

How do I get -1 for example?

#

Just like R^{2}/So(3)?

vivid halo
#

already taking pt/R is simple enough

foggy meadow
#

what's pt?

vivid halo
#

point

foggy meadow
#

Okay keeep going?

vivid halo
#

a nice example which is endlessly useful in practice is to consider a quotient like C/C* where C* acts by the obvious multiplication action on C

#

the resulting quotient has two points: one is the quotient C*/C*=pt which is a classical point with no internal symmetries, one is the quotient {0}/C*=pt/C* which is a stacky point with internal symmetries C*

#

this stack is incredibly useful when you consider vector bundles over it

#

a vector bundle over the quotient C*/C*=pt is just a vector space of course

#

a vector bundle over the quotient {0}/C*=pt/C* turns out to be a graded vector space V=\oplus_{n\in Z}V_n

#

a vector bundle over the quotient C*/C*=pt turns out to be a filtered vector space (...\subseteq F^{-1}V\subseteq F^0V\subseteq F^1V\subseteq...)

vivid halo
#

now everything in terms of filtered and graded vector spaces can be interpreted in terms of geometry over this quotient stack

foggy meadow
vivid halo
split basin
#

is there a more elementary approach here?

#

idk algebra

vivid halo
#

yeah hold on lol

#

I mean here the observation is just that a vector bundle on BC*=pt/C* is the same thing as a C-linear representation of C*

#

such a representation V splits into a direct sum of eigenspaces V_n for this C*-action where V_n is the subspace upon which z in C* acts by multiplication by z^n

#

if you have a filtered vector space then both the underlying vector space and the associated graded vector space are recovered by just pulling this vector bundle back to either of these two points

split basin