#serious-discussion

1 messages Ā· Page 516 of 1

static loom
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just think of it like gravity

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magic invisible hands pulling you down but you just don't question it with the same critcality cause you're used to it

leaden torrent
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šŸ—

long beacon
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hi how can i ask for help for meta questions (about the functioning of this server)? something like Math Stack Exchange Meta?

pale orchid
#

you can ask here, i guess

static loom
#

thinking of it in those terms is already thinking too seriously lol

cyan goblet
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man i gotta go major in humanities or something instead

long matrix
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ryc is a pigeon

deep mango
lilac snow
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i think it's like that part of physics that you can learn but not understand because our minds are finite in their understanding

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like trying to imagine higher dimensions

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breaks your brain

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and you still can't wrap your head around it

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no?

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that's the classical interpretation

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yeah

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lol

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plus i don't think it's one upon

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the quantum definition of spin

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or if you go look up the quantum model of the atom then you'll find a discription of all four numbers

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which might help in

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understanding

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i think spin is the only one of the four that is difficult, if not impossible, to entuit

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the other ones are easy to grasp

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what are you learning

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out of curiosity, of course

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right right

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then it shouldn't be way beyond

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i learnt the quantum model of the atom before i learnt all of that^

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yeah

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we cover all of that in high school

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i'm only a senior

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you'll get it no problem haha

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easy peasy for you

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(:

delicate knoll
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hello mathy people

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how do you do ?

long beacon
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hi a math room was closed before the question asker received a reply: #help-15 message

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write $i^i$ in polar form

fathom swallowBOT
#

vin100

long beacon
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$$i^i=(e^{i\pi/2})^i=e^{-\pi/2}$$

fathom swallowBOT
#

vin100

long matrix
#

well ping them with the reply otherwise they'll never see it

modern geyser
#

I guess it would just be e^ln(that number) * 2pi * i

weary steeple
lime sorrel
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it's not the best but it's correct

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I hope it helps tho

neat lintel
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thonkeyes howd u get 3k subs but no vid has 100+ views

lime sorrel
#

Don't ask questions.

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I accidentally published Riemann Conjecture's proof and got some followers but then had to delete it

median hill
hot cipher
#

1+1=?w

surreal sapphire
bright hill
#

$\varnothing$ should be the canonical empty set

fair mural
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varnothing

fathom swallowBOT
bright hill
fair mural
#

{} superiority

bright hill
#

everything is better than $\emptyset$

fathom swallowBOT
neat frost
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Yesh

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$\o \O$

fathom swallowBOT
fair mural
#

well it’s not actually that bad

neat frost
neat frost
bright hill
fair mural
#

shut up you can’t sully me

neat frost
bright hill
neat frost
rocky shuttle
#

$\not o$

neat lintel
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anybody wanna fight

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or have serious beef

sleek wing
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Odd request

rocky shuttle
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I want some beef steak

dire mulch
frigid lark
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is it ok to write on the seminar handout, that the prof is my supervisor?

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or do we usually write this stuff only on thesis...

tender tulip
neat lintel
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friday 1.50pm

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Im waiting

fair mural
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that’s oddly specific

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also why is there a phone number in there lol

astral iris
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He wants you to call him

median zinc
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Can you meet me instead

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1600 Pennsylvania Avenue

rocky shuttle
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Or me

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P. Sherman 42 Wallaby Way, Sydney

fair mural
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are there any abstract algebra prerequisites to reading loring tu’s ā€œintroduction to manifoldsā€, other than just knowing the definitions of a few algebraic structures?

tender tulip
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I’m bored what if I just decide to define some algebraic objects I know purely through set theory and subsets of Cartesian products with axioms

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Aka rules on the existence of its elements I guess

odd narwhal
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Then you'd be.... Formally defining Algebraic objects

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That's how they're defined

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Sets with n-ary operations satisfying some Axioms

dire mulch
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Bet.

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Damn bro, your in a different state, guess I can’t slide through. šŸ™‚

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You got lucky.

deep mango
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sully I don't know if this is a real address or not but I'm deleting this post, please for fucks sake do not post your real address on a public discord server which literally anyone can see

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If it was a meme address, I got got.

sturdy finch
neat lintel
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it was a random address but its ok

bright hill
neat lintel
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Allahuakbar

neat lintel
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my friend got banned here for saying there are 2 genders

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mods said he will get unbanned in 1 year

bright hill
neat lintel
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idk who banned him

neat lintel
neat lintel
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this earth been going downhill since 2019 lmao

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we wont

old fox
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hope it's not an inclusive we

bright hill
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weird how people expect to say the most racist, sexist mysoginistic shit and end it with "(joke)" and expect to get away with it

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worse yet

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they expect it to be funny

neat lintel
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I'm not gonna die till I get tired of math

bright hill
inner finch
neat lintel
bright hill
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well, good job

neat lintel
neat lintel
bright hill
inner finch
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tries pissing off mods
mods get pissed off
noooooooooo why'd they get mad it was just a joke

neat lintel
neat lintel
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we are just discord friends idk how he is

old fox
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I don't see any problem with anyone saying allahuakbar (assuming it isn't sarcasm)

inner finch
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lole

old fox
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that's just another way of saying omg

neat lintel
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somebody called the police

inner finch
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sure but why say this in chat

neat lintel
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just because he looks like that

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I got banned permanently from a server in 2019,
and the server went downhill since then...
it's probably like a desert now

old fox
inner finch
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It comes off as like a joke

neat lintel
inner finch
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and can be seen as insensitive

neat lintel
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we know what the issue is and talking wont solve it

old fox
inner finch
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?

bright hill
neat lintel
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but lets end the topic its just a word

old fox
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them being muslim?

neat lintel
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nah ppl say allahuakbar as joke

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i just randomly said it

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but its a word lmao

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can we not talk about it anymore

inner finch
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are they? And if they are, what purpose does sending allahu akbar in chat serve. At best it's a complete nonsequitor

neat lintel
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im leaving

inner finch
old fox
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well, this is discord. People don't say allahuakbar as a joke here where I live, so you might be right

neat lintel
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I think the religion itself just made a bad image because somebody like bin laden exists

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and saying a word of it always starts a convo like now

bright hill
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dude

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please stop

neat lintel
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but its not important

neat lintel
neat lintel
neat lintel
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yes

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not technically?

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it always has been

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in every context

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i thought technically means "to be exact"

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but yeah actually its 2 words

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yes but it implies there are not exact contexts where its one word

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ah alr

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also if you want same sentiments just say mashallah

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are you a muslim or do you just know much about islam

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im neither and speak arabic

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alr

inner finch
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been wanting to learn arabic for a while

bright hill
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mashallah is an exclamation similar to something like "wow" or "that's so cool" except it's more religious

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you say it when you see something impressive or favorable

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I'm not really sure what you mean by "wanting same sentiments"

hushed turret
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mashallah can be used when anything happens that you are thankful for really

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i don't think it's restricted to "cool" things lol.

neat lintel
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mashallah means thank god

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or praise god

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thats best english translation

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cool sentiments are not there

hushed turret
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yeah

inner finch
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oh isn't the translation something like the plan of allah is great

neat lintel
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idk if its that long

inner finch
hushed turret
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ive only heard praise be to allah

neat lintel
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yeah

inner finch
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makes sense with how we say inshallah hmmCat

neat lintel
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i dont even say mashallah

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idk a translation for omg though

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nah?

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inshallah is def not a translation for omg

odd narwhal
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Ya allah maybe

neat lintel
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i thought ur a liberal guy just critizing it

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arabic is ok, reading it without the little things on the words is like impossible for me

neat lintel
tender tulip
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Gonna ask this question again

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Can all abstract algebraic objects be considered as subsets of (nested) Cartesian products of sets of which have certain axioms over its elements

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Which is rather interesting

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Gonna try to define topologies through set theory

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Purely basic set theory, Cartesian products, power sets, existential quantifiers, some logic

neat lintel
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yes

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its not as interesting in my opinion though

tender tulip
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t is a subset of P(S) such that
null set element of t, S element of t
AND
For two elements X and Y in t
3. {x : x element of X AND x element of Y} is an element of t
4. {x : x element of X OR x element of Y} is an element of t

neat lintel
#

There are easier ways to word things less confusingly

tender tulip
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symbolically I guess

neat lintel
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Nah

tender tulip
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basically Union and Intersection

neat lintel
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i mean using words

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t is a collection of subsets of S where the empty set and S are within t.
t is closed under union and intersection.

tender tulip
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That defeats the purpose of what I’m doing cokeycola

neat lintel
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what are you doing then?

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people define topologies through set theory already

tender tulip
neat lintel
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you can always expand out to symbols but that just makes reading more convoluted sometimes

tender tulip
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In a way topologies sorta are a combination of two monoids over a power set I guess

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(t,Union) is a monoid cuz it’s associative and it’s identity is the null set

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(t,intersection) is a monoid cuz it’s associative and it’s identity is the set the topology is over

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That whole infinite Union, finite intersection thing might fuck with it

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infinite union is what screws me over

neat lintel
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you can still be wrong?

bright hill
neat lintel
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thats so cool is just off

bright hill
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but not like how it's used in english

neat lintel
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yeah

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ive heard it in exclamation

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like they believe something ive said to be interesting

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but not thats so cool

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you gotta localize in your translations

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you cant just have same semantics without context

bright hill
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but

neat lintel
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bruh

long matrix
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kakuii desu

neat lintel
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the purpose of translating is to make meaning and context apparent

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literal translations suck most of the time if they dont convey these

bright hill
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as I was saying

neat lintel
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there is probably a good translation for thats so cool

bright hill
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if you think something is cool you'd probably say "mashallah"

neat lintel
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but id need to think

bright hill
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that's what I meant

neat lintel
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we agree

bright hill
long matrix
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shh

tender tulip
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Is there a way to describe finite-intersection/infinite-Union closure through set theory in the way I described

honest veldt
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i have a huge dilemma

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i need to ask a pretty small question in a channel, but the last question posted there looks significantly more important and id be pushing it away from view

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can we duplicate all channels for a minute

long matrix
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be rude and crude KEK

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could open a thread

honest veldt
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Love that grindset, good idea

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New thread: important question, ignore that other one

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here valley

tender tulip
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NOOO

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Bernoulli inequality

honest veldt
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why does the fella bother putting 1 + nx_n <= (1+x_n)^n, doesn't nx_n alone serve the same purpose?

honest veldt
rocky shuttle
honest veldt
#

Oh actually? I thought the inequality just held because all terms of the binomial expansion were nonnegative bleak

tender tulip
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Classical case of induction proofing

honest veldt
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and this Bernoulli fella holds if 1 + x_n > 0?

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for all n

bright hill
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wait what

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if that was true, why did rudin mention the binomial theorem?

tender tulip
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0 < x
Base case: n = 2
1 + 2x__<__ 1 + 2x + x^2 = (1 + x)^2
thus 1 + 2x < (1 + x)^2

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assume the inequality is true

honest veldt
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I think the reasoning you and I used wasn't wrong either, darq, since he uses it in the very next proof

tender tulip
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Thus it is proved

bright hill
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but if that's true, then why the added 1?

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I hate that about rudin

honest veldt
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thank you once again rudin.... . . . . . . . . . . . .

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Clean stuff Miz, I just can't tell why he doesn't mention it at all

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you'd think he'd acknowledge its existence, but whatever

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should get used to this

bright hill
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btw, congrats on reaching chapter 3!

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being stuck on point set for a month must've been a drag lol

astral iris
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How is analysis

bright hill
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eh

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still not that interesting yet

astral iris
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Lol

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Nice

honest veldt
honest veldt
bright hill
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based

honest veldt
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but i enjoyed, it was worth

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cant wait to see how long this one will take.... i took a look at the exercises section, and some of them take up like half a page individually

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i fear for my life

bright hill
sick burrow
#

how to do math:
step 1: find a nice intuitive concept you want to formalize (distance, space, continuity, shape, etc)
step 2: find a nice formalism and set of axioms that describe the thing you want it to, and can prove the properties you want to prove
step 3: generalize generalize generalize
step 4: bleak

#

this post was made by Stone Spaces

rocky shuttle
#

Who is Stone Spaces...

sick burrow
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me

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my full name is actually Stone Spaces

fervent pebble
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^ can confirm

ancient flame
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my physics teacher made this problem for us LOL

waxen lily
#

amgus

primal seal
#

Phys 1(01)?

ancient flame
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AP physics 1

strong hull
#

Hey guys, Im not entirely sure if this is the correct place to ask but im self studying real analysis in high school and if anyone could help me get through the books and tutor me a little please drop me a DM... It would really be helpful bc im struggling with some of the exercises and proofs, and i couldnt find solutions for quite a few of the exercises. Thanks.

ancient flame
sleek wing
#

#fake-complex-analysis šŸ˜‚šŸ˜‚šŸ˜‚

strong hull
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so

ancient flame
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oh okay, then maybe it'll be a bit difficult to find one here (but it is possible)

strong hull
#

yes i really really need a study buddy i think

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self studying is hard for me bc i lose motivation sometimes, and its so frustrating to just figure out an entire textbook myself

hushed turret
#

what point are you at in your text

strong hull
#

well i am at dedekind cuts in Pugh's real analysis

strong hull
#

i think the motivation is a big factor for getting a study buddy or study grp

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bc like school can be stressful and sometimes im just so frustrated i kinda give up

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so im kinda desperate for a study buddy lol

hushed turret
#

i guess you can ask in #real-complex-analysis if anyone is at a similar point and would like to study alongside you

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but generally you should be fine asking there for help on specific problems/explaining things if you don't understand them

strong hull
#

alr

calm frost
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btw I ditched rudin a few days ago after chapter 2

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don't know whether it is due to skill issues or lack of studying or whatever but it was way too dense and uncomprehensible for me

neat lintel
#

baby or papa rudin ?

calm frost
#

baby rudin

bright hill
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and then I realized, this server is just a huge ass study group lmao

calm frost
#

I recommend using some of those books just for problems

bright hill
#

yeah, rudin require some mathematical maturity

calm frost
#

yep it is called basic topology

neat lintel
#

darq are you using rudin

calm frost
#

but I wasn't able to understand anythign after compactness

bright hill
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you can check out hatcher's notes on pointset topology

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they're more accessible

bright hill
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I'm not yet committed but I have finished chapter 1

calm frost
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tbh I kinda trusted myself too much and tried rudin as a first rigorous math textbook

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bad idea tho

neat lintel
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why not spivak

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spivak iirc is a good transition from handwavey hs math to serious math

calm frost
#

isn't spivak sort of like difficult calculus book?

calm frost
#

maybe I should use abbott or ross first

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my professor recommended me zorich but doesn't seem taht easy

bright hill
neat lintel
#

spivak's calculus is more like an intro to analysis

calm frost
#

maybe I should check it out

bright hill
#

you can check it out but if you've already done calculus I think if you ask in #book-recommendations they'll give you better recommendations for doing analysis

calm frost
#

okay

swift sinew
#

The kind architects of Minneapolis put a straight line homotopy in my neighborhood park

fast thistle
#

wth thats trippy bro

primal seal
#

Tell me you deserve a raise without telling me you deserve a raise

analog salmon
#

my cryptography class is gonna make me lose my mind

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for the simple fact that the permutation $$\sigma=\begin{pmatrix}1&2&3&4\2&4&1&3\end{pmatrix}$$ has the convention that $\sigma(1)=3$

devout nacelle
#

How is this representation even working lmao

long matrix
#

"sigma" = sigma^-1

torn willow
fathom swallowBOT
#

BYE BYE!

torn willow
#

AKA (1,2,4,3)?

analog salmon
fathom swallowBOT
#

cgodfrey

analog salmon
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for no apparent reason

neat lintel
devout nacelle
surreal sapphire
#

just flip the rows manan

devout nacelle
#

Oh

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This is so silly

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šŸ˜µā€šŸ’«

surreal sapphire
#

it's bad notation either way

devout nacelle
#

Yeah

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Cycle notation good 😌

surreal sapphire
#

its ok

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i never know whether to compose from left or from right opencry

devout nacelle
#

Kind of seems to be the best of the lot but gets a bit icky because of left-to-right or right-to-left conventions that different authors use

surreal sapphire
#

also in tex its kinda

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how much spacing should there be

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nobody knows

devout nacelle
#

Oh hmm, that's true

surreal sapphire
#

but yes, its the best available

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mainly because it doesnt take 2 lines for no reason

devout nacelle
#

No spacing, all the sets I permute have less than 10 elements, marked 1-9 sotrue

devout nacelle
#

Plus it checks out with how function composition works if it's read right to left

ancient flame
#

just got my free tuition confirmed :)

fervent pebble
#

AYYYY

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let's go

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where?

ancient flame
#

well that's for any florida public university

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state scholarship

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but im going to UF

toxic schooner
#

wait g mod is a florida man?

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everything makes so much more sense

ancient flame
#

LOL

toxic schooner
#

anyways nice gmod

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make metal teach u

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😌

devout nacelle
#

Congratulations gmod!

cold needle
#

nice bright futures clutch

toxic schooner
#

someone wish me luck for getting into a good uni as well 😭

neat frost
hushed turret
#

good luck shyshu catlove

bright hill
#

Shyshu, I believe in you!

neat lintel
ancient flame
toxic schooner
#

whats a community service hour

ancient flame
#

oh right you're in india

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100 hours of volunteering

neat lintel
ancient flame
#

this year

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even though I was eligible last year

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I got the aice diploma at the end of 10th grade if you're aware of what that is

neat lintel
#

Never heard of it

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What is it?

toxic schooner
#

like helping at places and stuff?

bright hill
#

I wonder if mit would notice me if I get a top 0.1% score in my country

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senpai mit catblush

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probably not bearlain

charred mortar
#

You can always apply

bright hill
#

applying isn't free iirc

toxic schooner
#

i mean, they probably have single one of those 0.1% score people applying there, so its not going to help much

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i think

toxic schooner
bright hill
toxic schooner
mint patio
#

Discrete math is actually kind of cool

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Or maybe it's just because the problems are more puzzly and less proofy LOL

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I was helping my friend out with some of her problems and had to read her textbook to understand, and it was so much cooler than I thought it would be. They're on relations right now. I love the stuff about representing relations using matrices and thinking about what compositions of relations look like and whatnot

#

Being able to study relations by representing them as digraphs is cool

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I love that stuff in general, when you phrase the same problem from a different point of view and it becomes more accessible to study that way

bronze pelican
#

Discrete math is hella cool

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More math depts should have discrete math courses

hidden violet
#

What is a non-empty set?

abstract mulch
hidden violet
#

K

wind abyss
#

@deep mango @vivid halo @neat frost here’s my school pizza

deep mango
#

I see

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That seems like the typical school pizza

bright hill
bright hill
#

wait wtf

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I didn't notice that

alpine kindle
#

that doesn't look nice

bright hill
alpine kindle
bright hill
dire mulch
#

Are you serious? Wait axiom of extensionality says what again? sets are determined by their elements?

alpine kindle
#

a set is uniquely determined by its elements

dire mulch
#

ah yeah I see.

alpine kindle
#

therefore the empty set is unique

vivid halo
#

It looks pretty lame

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But not horrible

neat frost
#

Looks like typical pizza

deep mango
#

slurp is in need of help

neat frost
#

Yes

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Which begs the question, ryc

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Where are the pictures?

deep mango
#

let's draw a line here between "pretty bad pizza" and "typical pizza"

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oh do you want to see 3 pizzas

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from the student probability seminar last week

neat frost
deep mango
neat frost
#

Obv it probably tastes bad because it’s school pizza, but it doesn’t look bad

deep mango
#

idk wtf these are

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but they were good

neat frost
#

Uhmmm

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Not my type of pizza

deep mango
#

left one was the best

neat frost
deep mango
#

yeah idk who has the task of getting pizzas for an event and goes "lemme get 3 weird ass pizzas" instead of at least getting one cheese

neat frost
#

Yeahh

deep mango
#

the left one was just margherita though

neat frost
#

Oh?

deep mango
#

and it was pretty good

neat frost
#

Then why does it look weird

hushed turret
#

what are the toppings on the middle one lmao

neat frost
deep mango
#

it was good but like

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why

hushed turret
#

wack

deep mango
#

right is eggplant, red peppers and olives

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i appreciate the free pizza but next time get 1 cheese, 1 pepperoni, and 1 veggie please

neat frost
#

Lol

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Yesh

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I’ve had sabich ā€œpizzaā€ a few times

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Pretty good

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That’s the wackiest pizza I’ve had

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Anyway ryc, any other pics you’re hiding hmmCat

deep mango
#

idk

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i would have to scroll through the archives

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there are no more recent pics

neat frost
#

I see

deep mango
#

i really really want to put together a nice photo website soon bleak

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the problem is that when i feel motivated to do things i try to spend that doing math

#

i need more energy

hushed turret
#

that is understandable

neat frost
#

Yeah

neat lintel
#

put more pizza pics pls

deep mango
#

i'll scroll way back

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let's see what's in the archives

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This was fucked up

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biscuits and sausage gravy

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way way too much food

neat lintel
#

it looks like one big egg

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that popped

deep mango
#

western middle of the US is crazy

neat lintel
#

western middle you say

deep mango
#

Yes

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This was in western Colorado

neat lintel
#

i wonder how the us is partitioned and what the true "center" of it is

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very weird

deep mango
#

Ah, we almost went to visit the geographic center of the contiguous states

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on the border of kansas and nebraska

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but it would have been a 2 hour detour for us so we didn't bother

neat lintel
#

And how do people from there consider themselves ?

#

Middle middle

deep mango
#

this is considered to be part of the midwest

#

How about this nice croissant and coffee in Barcelona

hushed turret
#

yum

neat lintel
deep mango
#

It's a chocolate croissant

neat lintel
#

sorry

#

it's called pain au chocolat

#

or chocolatine

deep mango
#

Yes I heard plenty about the chocolatine debates

neat lintel
#

pain of chocolate ? /s

brave hollow
#

being associated with anything french could be painful

deep mango
#

I don't think people in Barcelona cared much though

honest veldt
#

finally... . . . .. i got to the series part

#

i stand proud today

hushed turret
clever knot
#

YES

#

I hate this so much

#

my google search bar has been my basic calculator because of thi

#

s

earnest briar
#

If mathematics is difficult for me ( I am in the university, studying computer science), should I try building a solid knowledge foundation, or should I quit, because math is not for me?

sick burrow
#

You should quit. Stick to cs topics like computer graphics and machine learning

deep mango
#

If I'd been out then... 😩

#

So true gamma

sick burrow
deep mango
#

No. Shut up dont make me think about this bleak

#

I will go back eventually

earnest briar
#

are you talking about me? Shitposting?

sick burrow
#

Stick with math

astral iris
#

What kind of math are you doing

sick burrow
#

cs people who don't know math are awful

earnest briar
#

@astral iris just analysis, discrete math, linear algebra. The last two are fine, but analysis fries my brain a lot

astral iris
#

Ah yeah analysis is typically harder than those 2

#

So it makes sense you're struggling

#

I'd say to continue trying

earnest briar
#

I like math symbols

sick burrow
astral iris
#

That is a bruh moment

sick burrow
#

Me when I gatekeep math by using notation

earnest briar
#

I mean, for a non-mathematician pseudocode is much easier to understand than mathematical notation

leaden torrent
#

for a programmer it's easier to understand

earnest briar
#

not true, my dad understood ~80% of things that I wrote in pseudocode

leaden torrent
#

he'd probably also understand "sum 3n from n=0 up to 4"

#

also, what non-programmer would understand for(n=0, n<=4, n++)?

earnest briar
#

it is so clean

#

it is so good

leaden torrent
#

???

earnest briar
#

never mind

leaden torrent
#

i've TAed intro CS classes and a lot of students get absolutely mystified at for-loop notation for the first couple weeks

earnest briar
#

btw in what language do you put commas instead of semicolon in a loop?

leaden torrent
#

they figure it out eventually of course

#

well, you said pseudocode

#

ĀÆ_(惄)_/ĀÆ

earnest briar
#

okay

swift sinew
leaden torrent
#

like this is just anecdotal but

#

ive TAed intro CS and intro calc classes

#

students get \sum notation immediately

#

like within a couple examples

#

well, basic $\sum$ notation at least, something like $\sum_{\rho\text{ a 2-permutation of }\mathfrak{S}} f(\rho)$ would still throw them

fathom swallowBOT
#

Namington

leaden torrent
#

but that would also have much more involved pseudocode so

#

not counting that

#

meanwhile, a decent chunk (maybe 1/4?) of the class struggles with basic for-loops on the first assignment

#

common causes of confusion are using < when <= should be used or vice-versa, thinking they need to increment the index in the loop while also using n++ in the for statement, or not realizing that you can loop backwards (or do anything else when you loop, even)

#

among other things

#

also more language-specific stuff like failing to say int n=0 or auto n=0 in C++

#

also god forbid you need to teach them to loop through a standard template data structure in C++ lmao

astral iris
leaden torrent
#

holy shit students struggle with that

#

understandably, to be fair

#

but still

swift sinew
#

This is also even bypassing the obvious argument that pseudocode is not rigorous

leaden torrent
#

(auto is god's gift to mankind)

#

with mathematical notation you just declare an index and use words

#

im not saying programming notation is worse, to be clear

#

it does its job: be machine-interpretable

#

it's just pretty ass for communicating anything except algorithms.

#

(obviously it's very useful for algorithms, though, which is why algorithms in mathematics are usually presented in a very loose pseudocode)

#

oh and if you think these confusions about for loops go away later on in the course

#

i have graded finals for a second semester programming course

#

where the problem had a loop of the form for (int n = k; n >= 2; n = n//2) or something

#

and there was nothing else difficult in the problem, it was just parsing what the loop did

#

and so many students got it wrong

#

like way more than youd expect

#

30%-40% of the class

#

again this was a second semester course

#

the question wasnt confusingly written, the actual behaviour of the loop was just "increment a variable and print something" or something like that

#

all of the wrong answers were students not understanding what the loop did

#

at this point im going on an unrelated side-ramble but

#

man

#

this isnt as intuitive as youd think lmao

sick burrow
#

Namington have you considered the alternative hypothesis that cs students are just dumb

astral iris
#

Lol

#

Some of them are, but you'd have to be intelligent enough to finish a cs degree

sick burrow
#

Do you?

#

Cs get degrees

#

And with grade inflation Cs aren't exactly hard to get

leaden torrent
#

each time through the loop, divide n by 2 and round down

#

wait im using other language notation lmao

clever knot
#

well i mean if it is an int isn't it just trucation?

leaden torrent
#

in C++ itd just be n = n/2

clever knot
#

n /=2

#

?

leaden torrent
#

yeah

#

sorry its been forever since i wrote C++

#

thank god

#

// is comment lmao

clever knot
#

do people use auto in c++

#

I seen it introduced as a "here is this thing" and that was about it

leaden torrent
#

you wouldnt use it in simple for loops but you do use it if you have to loop through a standard template library structure like a map where the best way to do it is by defining a map<type1, type2>::iterator it and then (it = map.begin(); it != map.end(); it++)

clever knot
#

from what I recall auto just tries to match some declared value and set that as the type of the variable

leaden torrent
#

far cleaner to just go for (auto it : map)

#

god help you if your data structure doesnt have an interator object that permits it++ tho

#

since auto relies on that (or at least it did in C++11)

clever knot
#

sounds like for each loop

leaden torrent
#

like just work with the standard template library and youll understand the power of auto

clever knot
#

what benefits does it have over just coding in the right type from the start?

leaden torrent
#

none

clever knot
#

does it just make it more broader in use

leaden torrent
#

its just cleaner and easier

#

and requires less brain power working out wtf your types are if you dont care what they are

clever knot
#

hmm

leaden torrent
#
//without auto. Not that good, looks cumbersome
SomeType<OtherType>::SomeOtherType * obj1 = new SomeType<OtherType>::SomeOtherType();
std::shared_ptr<XyzType> obj2 = std::make_shared<XyzType>(args...);
std::unique_ptr<XyzType> obj2 = std::make_unique<XyzType>(args...);

//With auto. good : auto increases readability here
auto obj1 = new SomeType<OtherType>::SomeOtherType();
auto obj2 = std::make_shared<XyzType>(args...);
auto obj3 = std::make_unique<XyzType>(args...);
#

compare

clever knot
#

I see but ideally the programmer fully knows what obj they are working with when they do this?

#

like obj1, obj2, obj3 are

leaden torrent
#

sure

#

the point is that, if the type is either:

  • obvious
  • irrelevant
    then using auto produces easier and cleaner code
clever knot
#

Guess it isn't exactly hard to parse that the obj1 would have to be whatever type the thing on the right is

leaden torrent
#

in the examples i gave above, the type is obvious

#

in loops with iterators, the type is typically irrelevant

#

(as long as you can increment it, you dont care what "it" actually is)

#

in both cases, theres very little downside to using auto

#

abusing auto can hurt readibility, of course

#

auto output = foo(input) is terrible C++

#

dont do that

#

do int output or double output or char output or whatever

clever knot
#

for (int x : arr) cout << x << endl;

leaden torrent
#

thats another case where auto would be silly, yes.

#

like, here's an example: how do you loop through an STL unordered_map<int, vector<char*>> in C++ without auto?

#

yes, it can be done, and any C++ programmer knows how to do it

#

but do you know the type without looking it up? and do you really want to type out a 40-character-long type name every time, rather than the 4 character long auto?

clever knot
#

shame I don't know enough c++

#

my instinct would have said some "Object" type

#

but looking it up it doesn't seem to be a thing in c++

leaden torrent
#

you'd use the iterator type for unordered_map<int, vector<char*>>

#

and there are some cases where it makes sense to use this type

#

well, you're using the type no matter what

#

auto just automatically finds it for you

#

but there are cases where you want to spell it out to make it clear that's what you're using

#

in 99.9% of for loops though, you dont really care exactly what the iterator looks like — all you care is that you can increment it (and therefore use it to loop)

#

and if you want it to be clear, just add a comment

#

// loop through stringMap or whatever

clever knot
#

i need to really looking the whole c/c++ paradigm

#

this intro class hasn't taught us anything how it is structured overall

#

and I see lots of use of std:: but our exercise/book don't to that because they use the namespace

#

using namespace std;

leaden torrent
#

yeah thats considered dangerous practice in a lot of cases

#

but its fine for simple stuff

#

(i think C++ programmers tend to be too anal about using namespace std;, it's almost always fine)

clever knot
#

what is the difference between . and -> I was trying to help someone in there data structures course and I kept seeing ->

jolly thicket
#

using namespace std; pollutes the global scope

jolly thicket
#

i.e methods of a class use this pointer, so you can do this->member,

#

obj-> is equivalent to (*obj).

clever knot
#

oh

#

hmm

#

so you can just do

#

obj.

#

obj.method(); ?

jolly thicket
#

yah

jolly thicket
#

ie overloading *, . and -> operators to do different things

clever knot
#

I have an example that shows this

jolly thicket
#

yes, the dot operator can access a member of a class object

#

TimeHrMin is not a pointer, it's the raw class, so it's perfectly fine

#

now if it was TimeHrMin*, then you would need to dereference it to then apply the dot operator, just to access a member of it

#

which -> does

clever knot
#

well why would people want to have an extra variable that points to that variable to do that

jolly thicket
#

because pointers can point to various objects

clever knot
#

Guess just depends on use case

jolly thicket
#

i.e:

int PlaySound(Sound* mysound) {
 // do sound stuff
}
//...
Sound test;
PlaySound(&test);
clever knot
#

SongNode::SongNode(string songTitleInit, string songLengthInit, string songArtistInit) { this->songTitle = songTitleInit; this->songLength = songLengthInit; this->songArtist = songArtistInit; this->nextNodeRef = NULL; }

#

this was someones code from assignment and it just seemed weird that it was done like that.

#

like provided by the book i think

#

anyways I guess if you are passing a pointer into a function you would have to do that

jolly thicket
#

yeah

clever knot
jolly thicket
#

it allows you to reuse the function for various objects that are derived from, or are a SongNode

clever knot
#

can variables store functions in c++?

jolly thicket
#

yes

#

std::function<return_type(arguments)> my_fn

#

there is also the C-way, but std::function is more useful, esp. since it supports lambdas

jolly thicket
clever knot
#

hmm I just recall some languages you could store them and even pass functions as a paraamter

jolly thicket
#

thats self modification

clever knot
#

maybe that was javascript

jolly thicket
#

and i think only people from 1970 did that

clever knot
#

but not sure if c++ supports things like that.

jolly thicket
#

c++ supports that

#
std::function<int(void)> lol(std::function<void(int)> my_lol_fnc)
{ /* do ur stuff */ }
clever knot
#

do you know some resource I can get a run down on best practices and understanding the layout of c++?

jolly thicket
#

nope :/

frozen venture
#

Does lcm(a,b) = lcm(a,c) imply that b*c divides a?

#

Where b and c are relatively prime

earnest briar
#

@swift sinew I wasn't arguing for or against anything. That was merely a conclusion made on a basis of first and second-hand experience

dire mulch
#

It gets very messy.

dire mulch
clever knot
#

it was an example that was predefined in someones online code assigment

#

like given to them to use

dire mulch
#

Oh ok.

#

My main reason for disliking it is that it’s way too long.

jolly thicket
#

esp. when you have to read old codebases

fair mural
#

do any of you have anything you did that really helped you when you started doing proof based math?

torn willow
#

Olympiads

cloud glen
#

Hi I was wondering if there is a formal proof about Taylor series coefficeints being equal to the 'limit' of orthonormal projections of polynomials of a certain degree to that function

rose dock
#

The limit as the interval around the point where you're taking the Taylor series of shrinks?

tender tulip
ancient flame
#

then to put the cherry on top I always say "ohhhh that makes sense"

fair mural
#

that doesn’t help at all

ancient flame
#

exactly!

swift sinew
# fair mural do any of you have anything you did that really helped you when you started doin...

Gathering and really understanding definitions and theorems and understanding why they are the way they are (why this rather than a slight variation to the definition or theorem) and understanding why a proof technique makes sense for a given problem, are all extremely helpful in developing skill in proving things. I’d honestly argue that they’re some of the most important things to stress on when first getting into proof-based math

primal seal
#

Agreed

#

Messing with hypotheses and investigating the outcomes and coming up with counter examples should be added tol

near fox
#

Here's an alternative suggestion that I haven't seen mentioned here at all: studying with a friend enabled me to study 10x more effectively, better than finding a better book, online notes or lectures, or even a teacher. My friend helped motivate me every day and made the learning more interactive. I know a lot of people are just self-studying here, but if you can find a friend (in real life, not online) to study with that would be very beneficial in many cases.

primal seal
#

Yeah that trumps all

#

Difficult to do when your friends have families or No interest whatsoever in mathematics. But it’s the best possible advice for younger folk here and, especially, enrolled students

vapid kernel
#

Hey. About that: how do you keep yourself studying different things as you get older and work piles up? I'm a math teacher and I keep struggling to study math at all, let alone things beyond whatever I teach at high school.

primal seal
#

It can be difficult to sit and read through chapters of dense (esp.math) books without large chunks of time- or consistent time at that (since you know it won’t amount to much if it’s not consistent to some degree).

One thing I did when I had less free time was to read what I could in whatever time I had, but I’d take exercises corresponding to that material everywhere with me

#

@vapid kernel

vapid kernel
#

Consistency always gets me. Teaching is a time sink like no other, partially because it sinks your time outside of class as well (and energy)

primal seal
#

I completely understand man, you have my respect; not sure I could do it either if I were in the same boat

vapid kernel
#

Are you also entering your thirties?

#

Really miss having some free time like I had a few years back. Not even looking back to when I was in university

near fox
#

I am in my thirties. I'm a mathematician but even then I find it tricky to find time to read or learn new things unless they're directly related to my work.

#

I sometimes look back at my old notes from school and am surprised how much I forgot

velvet dagger
#

Damn

primal seal
#

Old folks home in here

toxic schooner
velvet dagger
#

Still closer to 20 years old than 30 but not for much longer

#

I miss being in college 😢

plucky dawn
#

Is anyone here a trader for a prop trading firm

velvet dagger
#

I'm considering that as one of my top non-academic choices for a job

#

Basically my top 3 atm are academia, trading/quant research, and research in tech

plucky dawn
#

that's fair man

#

I've got an offer for BBIB & an offer for a top prop shop and I'm weighing my options right now so I wanted to ask some people haha

rancid meadow
#

chase the bag

neat lintel
plucky dawn
velvet dagger
#

@plucky dawn it's probably fairly firm-dependent. Another relevant factor is time

plucky dawn
#

I guess one of the big concerns i have is that I've heard that traders' compensations are capped after a while (unless you make head of trading/partner) & there's zero exit opportunities

velvet dagger
#

Hmm, so what I've heard of is that you get performance bonuses. How good those are, again depends a lot on the place

plucky dawn
#

Where I'm from, I think it goes from 150k USD first year -> around 600k in 5th year

#

all in comp

#

I guess I'm concerned that the comp will eventually be capped at high 6 figs

velvet dagger
#

So, my take is that 600k/year is... enough to set yourself up perfectly imo no matter where you live

#

So that's where I'd say the other factors kick in

#

Like I'd rather work closer to 40-50 hours a week and stay at high 6 figure forever than cross to 7 figure but have to sleep in my office

plucky dawn
#

that's perfectly fair

#

For me though, my goal has always been to get to a billion bucks

velvet dagger
#

Is that realistic even in banking?

plucky dawn
#

It's theoretically possible if you invest the vast majority of your returns in the hyperleveraged Australian housing market

velvet dagger
#

I feel like the number of people who work in banking is... quite a lot higher than the number of people who are billionaires

#

And given that they probably prioritize money over most other things I would think a lot of them have fairly good ideas how to invest their income

#

But yeah I don't have enough detailed info to be of particular help here. If you're optimizing for money and think that banking does win there long term then that's probably the strat? Unless there are other factors I'm yet unaware of

plucky dawn
#

yeah

#

tbh I've been trying to get in contact with senior people in industry

#

to see what the progression really is

velvet dagger
#

That's a good strat

plucky dawn
#

all I have so far is wall street oasis hearsay, which as you would be aware, is highly unreliable

velvet dagger
#

But yeah I've mostly not looked much at banking because my impression about the hours makes it feel... not very worth it to me relative to my financial goals

plucky dawn
#

that's a very crucial consideration tbh

#

are the 80-90 hours a week worth it

#

even if you earn more than trading in the long run, it's only like 40% higher, not a different magnitude entirely

velvet dagger
#

Perhaps said goals are modest, but pretty much I'm gunning for, first owning my place, then having enough passive income to, let's say double my lifestyle if I'm not going out of my way to be conservative

plucky dawn
#

tbh that's probs all you really need. Apparently satisfaction from money depreciates exponentially fast after you earn >$300k a year

velvet dagger
#

But I'm on a grad student stipend right now and I'm surprisingly not wanting for much lmao. I'm not a sports car person or anything. So I feel like once I own a place, even if I live in a place like NY or Bay Area, no way I'd be spending more than... 200k/year? Even if I just throw money wherever I'd like it

#

So okay let's go ballsy and say 500k passive income after tax is my big financial goal. And I think I can hit that somewhat quickly in trading

plucky dawn
#

unless you're buying a tesla every year haha

plucky dawn
velvet dagger
#

That was my mental timeline lmfao

plucky dawn
#

oh wait passive income

#

that would be difficult

#

maybe 14 years?

velvet dagger
#

Or I guess I meant 10 hours after working. So that clock isn't starting for a while and I kinda have some ideas on investments

plucky dawn
#

wdym 10 hours after working

#

like income from 10 hours worth of work?

velvet dagger
#

*years not hours

#

rip

plucky dawn
#

ahaha

#

I was gonna say

#

don't think ur gonna make $500k in 10 hours in trading

velvet dagger
#

My investment ideas are fuckin cracked lmfao

#

šŸ˜›

#

Nah but yeah

plucky dawn
#

unless you yolo gamestop

plucky dawn
velvet dagger
#

Actually I'll move to DMs this is getting a bit specialized

sacred elk
#

2/6 babyyy sheeeeesh
šŸŸ©šŸŸ©šŸŸ©ā¬›šŸŸ©
🟩🟩🟩🟩🟩

https://wordlegame.org?challenge=Y3JhdGU

bright hill
hasty silo
#

can anyone tell me if this is wrong

#

randomly found this youtube video

#

and im assuming some random guy didnt solve this but his video has 0 dislikes also

crystal stream
#

if it's not wrong i will record myself eating a hat with a fork

fair mural
#

i will hold you to that

odd narwhal
#

I will eat a fork with a hat

fair mural
#

even better

bright hill
#

if RH is proven wrong I'll literally give whoever did it another million

#

just to spite everyone even more opencry

neat lintel
#

The hat

deep mango
#

That's too much guac for me to eat in one sitting

neat lintel
#

Never a thing as too much guacamole

rocky shuttle
#

But can you approximate the hat from below using simple functions?

neat lintel
#

Something something pi

delicate knoll
ancient flame
hasty silo
# swift sinew > Has 0 dislikes

lmao this is exactly why i hate that youtube removed dislikes lol. (I downloaded an extension that adds them and nobody who has it happened to also dislike the video)

fair mural
#

isn’t this an analysis question?

rocky shuttle
#

It is

fair mural
#

that’s a question in axlers ladr lol

#

not even calculus, just straight up analysis

empty stratus
fair mural
#

you know what i mean sully

rocky shuttle
#

Calculus is fake analysis

empty stratus
#

It's actually a book about algebraic geometry.

#

Doesn't even mention integration.

#

😭

zenith forge
#

gabe

steep mountain
# fair mural

this wasn't uncommon
its sorta teasing into some functional analysis lol

#

at least thats what i felt during my course

toxic schooner
tribal talon
#

can someone explain to me why 0! = 1?

bright hill
#

sure

#

you see

sleek wing
#

PauseChamp

bright hill
#

I think we can agree 1!=1, 2!=2*1, 3!=3*2*1... etc

rocky shuttle
tribal talon
#

like why isn't this wrong?

torn willow
#

this is wrong because it's gibberish

tribal talon
#

I just used the gamma function to evaluate -1!

sleek wing
#

Factorial isn’t defined for negative numbers for a start

#

And why can’t 0 times infinity be 1

tribal talon
#

it's undefined but I think it should be ZEROOOO

sleek wing
#

Take the limit of 1/x times x as x goes to infinity, this clearly approaches 1

sleek wing
tribal talon
#

what?

sleek wing
#

The empty product is 1, the number of bijections from the empty set to itself is 1

#

There are so many arguments I could use here

torn willow
#

(-1)! doesn't even exist

tribal talon
#

I used the gamma function

torn willow
#

You are using what your calculator thinks is the gamma function

tribal talon
#

I just don't understand why plugging it into the formula contradicts 0! = 1

torn willow
#

Your calculator can output whatever it wants when function at a point is not defined

sleek wing
#

The gamma function at -1 is undefined isn’t it

torn willow
#

(-1)! Is "teddy"

tribal talon
torn willow
#

Is equally valid as saying (-1)! Is infinity

bright hill
#

even tho repeated addition doesn't make sense there

#

it's called domain expansion (or some shit idk)

torn willow
#

Ah domain expansion

bright hill
tribal talon
#

bruh, okay, I'll just accept it as it is, but it still breaks when I plug it into the equation

sleek wing
#

,w plot the gamma function

fathom swallowBOT
sleek wing
#

Thanks wolfram very cool

bright hill
torn willow
#

,w gamma

fathom swallowBOT
bright hill
torn willow
#

,w gamma function

sleek wing
fathom swallowBOT
sleek wing
#

I don’t see why you’re confused by this

torn willow
#

Genius

tribal talon
#

okay I get that, but how come when I sub zero straight into the formula it doesn't work

bright hill
#

what can we do without wolfram

torn willow
#

Life

bright hill
#

coz the formula only works for n>0

tribal talon
#

but... but... you solved for 0! and N = ZEROOO

bright hill
#

yes

#

it made sense to define 0!=1

#

coz that's how mathematicians do stuff

neat lintel
fathom swallowBOT
neat lintel
#

You're welcome

bright hill
neat lintel
tribal talon
bright hill
#

yeah, exactly

tribal talon
#

1! = underfined

bright hill
#

no it isn't

#

1!=1

neat lintel
#

0! = 1, (-1)! is undefined

bright hill
#

@tribal talon just think of it like this

tribal talon
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But I just demonstrated that 0! Equals undefined, and subbing that into 0! For 1! Gives 1 times underfined

neat lintel
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n! = n(n-1)! holds for n>0

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So your argument is wrong

bright hill
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4!/4= 3!, 3!/3=2!, 2!/2=1!

tribal talon
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I'm really sorry for stupid quetsions, it's just this idk how math

bright hill
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right?

neat lintel
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It's ok to ask questions to understand things, even if they're stupid

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No need to be sorry

tribal talon
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by that arguement, you'd agree, 4/4 = 1, 3/3 = 1, .... 0/0 = ONEEEEEEEEEEEEEEEEEEEEEEEEE!

bright hill
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sure

sleek wing
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No because dividing by 0 isn’t well defined, dividing by 1 is

tribal talon
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I love maths, it's just some of this stuff is so axiomatic with logic but it's just wrong apparently and it's annoying me

neat lintel
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For this argument to work we need wheel theory

sleek wing
sleek wing
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You’ve been told that n! = n(n-1)! Only holds for n > 0 and yet you keep trying to apply it to n= 0

bright hill
tribal talon
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Yeah but I'm using your arguments that you used to prove something wrong and I break it but apparently i'm in the wrong

sleek wing
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So we try and extend the definition by rearranging that definition to a form that does work

bright hill
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domain expansion

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that's what I'm talking about

sleek wing
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so the form n!/n = (n-1)! Actually still does not work for n = 0 because it is identical to n! = n(n-1)!, but we can define 0! using it

neat lintel
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0/0 = ⊄

deep mango
tribal talon
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= 1

neat lintel
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No

tribal talon
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think of it like this

deep mango
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8/4 = 2
6/3 = 2
4/2 = 2
2/1 = 2
0/0 = 2

tribal talon
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you can't have nothing if you have nothing to compare it to so it must be something