#serious-discussion

1 messages · Page 9 of 1

storm sage
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yeah I can tell the spacing is pretty weird lol

lost surge
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Another alternative is $\sum s^{(n-1)\dots 0}f^{(0\dots(n-1))}(0)$

fathom swallowBOT
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PhysMan

storm sage
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it's nice though I agree

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it can get confusing fast though

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if you write the indices a lot

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and in different places

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(like subscripts, the denominator of a fraction, etc)

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it's a nice way to visualize what's going on though

blissful wigeon
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just to clarify to myself, differentiable is just a fancy way of saying the derivative graph is continuous, is it not?

lost surge
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No.

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A graph can be continuous but not differentiable.

storm sage
lost surge
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Such as a cusp.

blissful wigeon
lost surge
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Oh sorry.

storm sage
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differentiable just means that the derivative exists

blissful wigeon
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the blue one is the function itself

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obviously

storm sage
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if f is everywhere differentiable, f' is not necessarily continuous, but interestingly, it does satisfy the intermediate value property

chilly hull
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oh its the opposite

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nvm

blissful wigeon
chilly hull
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i read it wrong

storm sage
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desmos is probably just too dumb to display that though

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lol

blissful wigeon
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you said the derivative only had to exist

storm sage
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yeah and the derivative of the blue function doesn't exist at x=-1

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differentiable means that this limit exists:
$$f'(c) = \lim_{h\to 0} \frac{f(c+h) - f(c)}{h}$$

fathom swallowBOT
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Eric Tao (he/him)

blissful wigeon
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just to clarify, they meet with a a ≥ and >

storm sage
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yeah

storm sage
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for c = -1

neat lintel
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Are you going to give advanced ?

blissful wigeon
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yeah, my mistake there, that makes more sense now

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thanks

wicked ore
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Can a function be differentiable but its derivative is not continuous? @storm sage

arctic grove
wicked ore
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Oop

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Maybe that’s a stupid question

neat lintel
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It’s a yes

arctic grove
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I think the answer is yes

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lets go hype

neat lintel
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x^2sin(1/x)’s derivative at x=0 can be found with squeeze theorem

wicked ore
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Jesus

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Ok that’s not like

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Obvious

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Lol

ancient flame
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LOL

neat lintel
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It’s bounded above and below by x^2 and -x^2

wicked ore
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lmao

arctic grove
wicked ore
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How

arctic grove
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well its not something u can immediately think of probably

wicked ore
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Yeah that’s what obvious means

arctic grove
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but its what u can easily get to

neat lintel
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It’s a limit technique

arctic grove
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coz its got the perfect combo

wicked ore
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I mean I was thinking an obvious counterexample would be a piecewise function but that doesn’t work

arctic grove
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an oscillatory limit paired with a nice funciton

wicked ore
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Yeah I have never seen that before

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But that’s p cool

neat lintel
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The idea is just f<=g<=h implies f’<=g’<=h’

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So if you make x approach a value and the f’ and h’ are equal

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You found g’

wicked ore
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Ah

wicked ore
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Like

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-1 <= sin <= 1, but 0 <= cos <= 0 isn’t true

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I feel like I’m making some obvious mistake though

neat lintel
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Ah yeah

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No you broke it apart pretty well

wicked ore
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Hm

neat lintel
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I need to restrict my hypothesis more

arctic grove
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i think squeeze only works for limits

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not derivatives

neat lintel
arctic grove
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coz i have never heard of a squeeze for derivatives catThin4K

neat lintel
arctic grove
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but still

wicked ore
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He means it doesn’t work in that way for derivatives

arctic grove
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yeah

neat lintel
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I saw it pop up multiple times

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I guess it’s just an introductory analysis thing

wicked ore
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Ah

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I haven’t done analysis yet

neat lintel
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That’s actually what they start with

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Feeding you counterexamples to unintuitive scenarios

wicked ore
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Ah

arctic grove
wicked ore
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Yeah I’d heard of the weierstrauss function that’s kinda insane

arctic grove
wicked ore
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Seems like it’s doing a rigorous foundation for calc, but since you’re dealing with infinity it brings in a bunch of unintuitive baggage

arctic grove
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its much more than that, at times u treat/build it all from the ground up

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which can be painfully boring/too formalistic to be fun

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but it has its good parts

wicked ore
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Ah, even construction of the real numbers? How do you even do that lol

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Ah

arctic grove
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metric spaces

neat lintel
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You can construct the real numbers in multiple ways

wicked ore
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Cause rationals make sense, p/q set builder boom done

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But real numbers…

arctic grove
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dedekind cuts dont exist, dont @ me

wicked ore
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Ah

arctic grove
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R is the completion of Q as a metric space

wicked ore
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Completion as a metric space?

arctic grove
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that means every cauchy sequence converges to something in that space

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yups

neat lintel
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In fact for undergrad math EXPECT every intro to field X course to construct the real numbers in their own way. Its either algebraic, set theoretic, topological/analytic or something similar

wicked ore
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Why would someone care about Cauchy sequences converging

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What is a Cauchy sequence

arctic grove
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thats not the rigorous definition ik

wicked ore
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Oh a

arctic grove
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but it gets the idea across well

wicked ore
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I just looked it up

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Pretty straightforward definition actually

arctic grove
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yeah

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very simple

wicked ore
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Literally a sequence that should converge to a value

arctic grove
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but they are extremely useful

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and critical to get a grasp of

wicked ore
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And it makes sense that you’d want your number line to have every sequence converge

wicked ore
neat lintel
wicked ore
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Whoa

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What

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Lol

neat lintel
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We call spaces in which every Cauchy sequence converges COMPLETE

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the reals are complete

arctic grove
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cauchy sequences are sequences in which the difference between consecutive terms can get arbitrarily small

wicked ore
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Yeah I mean “should” in the sense of constructing a smooth, complete number line

arctic grove
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oh yeah sorry

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im jee pilled nvm that

wicked ore
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No?

neat lintel
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No

wicked ore
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What about it isn’t

deep mango
arctic grove
neat lintel
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Cauchy sequences say that any two elements in ur sequence can become arbitrarily close to one another for large enough N

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That doesn’t mean those two values that become super close (to each other) converged to something

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They could’ve diverged

deep mango
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The differences between consecutive terms of the partial sums of the harmonic series converge to 0

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But the partial sums of the series are not a cauchy sequence

wicked ore
neat lintel
# wicked ore Imma be honest I dont understand what this means

Just because element x got super close to element y as time tends to infinity doesn’t mean that x or y converged to something in the giant space it lives in. All we know is “x converged to y” in a sense. We don’t know if y converged in the set so we don’t know if x converged either

arctic grove
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oh

deep mango
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Cauchy sequence = for each epsilon, there's a point after which all elements of the sequence are within epsilon of each other

wicked ore
wicked ore
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Maybe I’m being dumb

neat lintel
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I’m being hand wavy for a reason

wicked ore
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That’s not my intention

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I just don’t get the explanation, that’s all

neat lintel
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Let’s say you have two sequences x and y that are implied with indices

wicked ore
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Ok

neat lintel
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They get super close to each other as n grows super large right

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How do you know the sequence x or y converged in the space tho?

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All you know is the sequences converged in a sense to each other

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But as a duo they might diverge relative to the space they live in

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Blows up etc

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Goes to an element not in the set

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Think of a Cauchy sequence which converges to sqrt(2) as time goes to infinity

arctic grove
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(or start oscillating between many elements)

neat lintel
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But claim you only know about rationals

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It’s definitely Cauchy

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Did not converge in the set of rationals

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So it’s a Cauchy sequence that diverged in Q

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But it converged in R

wicked ore
arctic grove
storm sage
arctic grove
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who knew geometers can explain analysis so well sotrue

wicked ore
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But then

arctic grove
storm sage
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so for example if f'(3) = 80 and f'(5) = 90 then somewhere between 3 < x < 5 we have f'(x) = 89

neat lintel
wicked ore
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What’s wrong with saying Cauchy sequences “should” converge, in the context of trying to construct a smooth number line?

arctic grove
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this will not be considered topology by anyone

wicked ore
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We know Q isn’t smooth because we have sequences that don’t hit anything, but they get arbitrarily close to a value

arctic grove
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even if its topological

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its used and first seen in the context of analysis

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smh

neat lintel
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if it wasn’t a limit point it is now!

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The space is now complete

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Spaces are not always complete

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In fact we’d really like them to BE complete

arctic grove
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they are very holey at times

wicked ore
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Ah, so that’s literally

arctic grove
wicked ore
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What complete means

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Yeah

arctic grove
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Homology moment

neat lintel
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We have a formalism to make it happen

arctic grove
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actually

wicked ore
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Although I guess another more vague question is

arctic grove
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is C complete as a metric space?

neat lintel
wicked ore
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How do we know the Cauchy sequence construction of real numbers works

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As in, how do we know there’s no holes left, in a sense

neat lintel
arctic grove
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thats where topo comes in

neat lintel
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It turns out the completion of the reals is equivalent to its closure

arctic grove
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the geometer can explain that better

neat lintel
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They are intimately related

arctic grove
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thats sick

neat lintel
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It is not true in general

arctic grove
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i didnt know that

arctic grove
wicked ore
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Closure in topological terms

neat lintel
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A closure says “find every last limit point of this set and put it in the set we have rn”

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It’s equivalent to the set union its set of limit points

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A completion focuses specifically on placing Cauchy sequences in the set

wicked ore
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Ah

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Wait I just looked up what a limit point is

neat lintel
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Every complete metric space equals its closure im p sure

wicked ore
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And it’s very similar

neat lintel
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Let me check

wicked ore
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It’s like if you generalized the “arbitrary closeness”

neat lintel
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That’s a super strong claim

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I got it

wicked ore
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A limit point of S is a point in X such that every open neighborhood contains another element of S

neat lintel
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Complete metric spaces must be closed but closed spaces need not be complete

wicked ore
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Closed metric spaces need not be complete?

storm sage
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what is a closed metric space

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isn't every metric space by definition closed with respect to itself

neat lintel
storm sage
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oh okay

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that makes more logical sense

full isle
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no such thing as a closed metric space

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a closed subset of a metric space you mean

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the proof roughly has to deal with looking at cauchy sequences

velvet dagger
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Yeah this is one of the few things I don't like as much about Baby Rudin, it isn't clear on what properties are those of a metric space (so they hold for subsets by virtue of subspace topology) vs those which are properties of subsets of a metric space

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Closedness is a property of a subset of a metric space, meaning if you want to say "A is closed", you must specify "as a subset of X".

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While completeness is a property of a metric space

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Now, if A is a subset of X, then you can think of A as a subspace, either in terms of open sets or in this case by restricting the metric

bright hill
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Yeah but I don't believe in that definition

mint canopy
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Don’t worry, that definition doesn’t believe in you either <3

bright hill
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all you mofos sotruing me ain't got no shit

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you tellin' me in the discrete topology every function is continuous?

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get tf outta here, that shit ain't real

vivid halo
arctic grove
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darq yes we are collectively lying to u!

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we want to make u a bad mathematician

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almost as bad as john gabriel!

daring socket
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what txtbook

tender tulip
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neat thing I noticed: For a subring $B$ of ring $A$, $B$ is a two sided ideal of $A$ if: $\forall a \in A, b \in A (a \in B \vee b \in B \Rightarrow ab \in B)$
But the conditional becomes a biconditional if $B$ is a prime ideal.

fathom swallowBOT
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Mizalign

tender tulip
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actually if B is a subset of the A ring

dapper badge
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But a subring B contains the same multiplicative identity as A, so if it were an ideal then it would be all of A

tender tulip
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hm?

dapper badge
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Nvm, I was responding to what you said before clarifying B is a subset, not a subring

dapper badge
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You said that if B is a subring of A, then B is a two sided ideal of A if this condition holds

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But if B were a subring, it contains the multiplicative identity as A. The only ideal containing the identity is the whole ring, hence B would be equal to A

tender tulip
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WHAT

dapper badge
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Uhh, which part is "WHAT" worthy

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Or is my brain on too little sleep rn

tender tulip
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isn’t that for a field

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also I thought an ideal is a subring

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kinda like the ring theoretic analogue of a regular subgroup

dapper badge
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Miz do you like for your rings to have multiplicative identities

dapper badge
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Then ideals are not subrings

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If an ideal I of a ring A contains 1, then for all r in A, we have r1 is in I by definition of an ideal

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Therefore r in I, hence I = R

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Ideals are analogous to normal subgroups in the sense that the kernel of a homomorphism is an ideal

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Ideals can also be thought of as submodules of the ring viewed as a module over itself

dapper badge
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And that follows from the fact that every non zero element is invertible, hence xx^-1 = 1 would be in the ideal, which I've shown implies that the ideal is just the whole field

dapper badge
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Timo I'm eating a yummy jalapeno and cheese bagel RIGHT NOW

pure sun
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Did you bring enough to share with the whole class?

dapper badge
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No I brought it for show and tell

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No showing either though

pure sun
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Haha

maiden bear
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I was about to make a terrible topology joke with the bagel

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Didn't let my intrusive thoughts win

dapper badge
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why do seagulls fly over the sea

maiden bear
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good question

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makes me wonder what they would be called if they flew over the bay

dapper badge
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probably S1 x D2 or something

maiden bear
dapper badge
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he looks contractible tbh

maiden bear
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he has to fit into the spaceships somehow after all

dapper badge
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ig if it's a hyphen

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R2 - D2

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then its homotopy equivalent to circle

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agony

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timo you ever been rock climbing?

maiden bear
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i have not

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not the biggest fan of heights

dapper badge
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I'm going for the first time today

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kinda nervous, but I think it'll be fun

maiden bear
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sounds nice walter

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enjoy!

pure sun
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Thats cool walter

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I know lots of people who do it and they all love it

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I hope you have a good time

dapper badge
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my biggest fear is that it will rain and the rocks get wet and I slip and fall for several miles

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which makes no sense because it's indoors

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but I will update all of my fans on how it goes

maiden bear
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They pour water from above for a more realistic experience

pure sun
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Hahaha

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I have a traumatic rock climbing memort from when i was a kid

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I was at some kind of childrens museum that had a rock wall and i wanted to climb it

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But like half way up my leg cramped and i fell off

maiden bear
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agony

pure sun
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And i was so embarrassed i started crying

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And 20 years later i am still scared of rock climbing lol

maiden bear
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Well i guess i did go climbing once

dapper badge
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Thanks Buncho, I find great comfort in your story

maiden bear
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which doesn't really count tho

dapper badge
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jk jk lol, that really does suck though

maiden bear
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i climbed up 2 thingies

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looked down and went like

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"hell no"

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and quit

dapper badge
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have you always had a fear of heights timo

pure sun
maiden bear
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not really

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it just randomly developed at some point

dapper badge
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bizarre

maiden bear
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i also despise elevators

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always take the stairs

dapper badge
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I guess it happens though, I only became scared of the ocean recently

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but ofc there's nothing irrational about fear of heights or ocean

maiden bear
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Yeah the ocean is scary as hell

dapper badge
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there are those big squid people

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or not people

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squids

maiden bear
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probably squid people as well

surreal sapphire
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cephalopods are great

dapper badge
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I suppose so

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I go to the aquarium a good bit as like

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exposure therapy

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But now I think I'm just dependent on the glass barrier between me and the unknown

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jellyfish look really pretty though, I'll give them that

deep mango
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Rock climbing is so fun!

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Are you going to do bouldering or top rope?

maiden bear
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Aquariums are kinda cool but i always feel bad for the marine animals

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because like

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ocean very big

dapper badge
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bouldering!

maiden bear
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aquarium very small

deep mango
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Bouldering is where you dont have a harness, it's shorter (like 15-20 feet) and there's big cushions on the ground

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Ok nice

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That's more fun imo

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And also easier on the heights thing

dapper badge
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It seemed like it, yeah

maiden bear
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maybe i should give it another go some time

deep mango
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I thought I was super into like

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The idea of open ocean swimming

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When I was swimming last week in the ocean at the beach

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I was over a sandbar, and suddenly I came up to a 45 degree incline that just led into black

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And something set off in my body and I just booked it in the opposite direction without even giving myself time to think

dapper badge
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instinctual

deep mango
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So I'm wondering now if I'd actually like open ocean swimming

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Lol

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But I still want to try!

dapper badge
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yeah I've got massive respect for open ocean swimmers

maiden bear
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I've been wanting to try stand up paddling

deep mango
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That's fun

maiden bear
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it looks like a relaxing activity

dapper badge
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I used to do competitive when I was younger and thought I'd be able to do long distance open ocean when I was older

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but it was simply not meant to be

maiden bear
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there's this video of a stand up paddler getting his shit rocked by a dolphin

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hilarious

pure sun
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I kinda wanted to try rock climbing again but there is just nothing near me :(

maiden bear
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Try that museum wall again

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you'll get it this time

pure sun
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The closest place (which might not even be open anymore) is like 40 minute transit each way

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Hahahaha

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I will crush the childrens museum rock wall

maiden bear
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I believe in you catthumbsup

pure sun
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I looked it up

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Its 10-15 minutes away by car

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But 40 minutes by public transit

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The transit in my city is so bad

hushed turret
pure sun
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I miss living in chicago

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The bus and train system was great

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Most people i knew didnt have a car

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St louis is really car centric though

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Which makes it hard

dapper badge
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missouri, more like misery

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living in/near an unwalkable city is very annoying though

pure sun
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Yeah :S

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I really dont want to learn to drive but i might have to at some point

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I have anxiety about driving and anxiety about not driving and idk which one will win out hahaha

dapper badge
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I think I get it, I'll go to any lengths not to drive in the city

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I'm okay with suburbs, especially when the roads are empty

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But I do still feel like driving is something most people would benefit from knowing

pure sun
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Yeah i wont argue with that

maiden bear
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I should get my license at some point as well

pure sun
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I just dont want to like go through the hassle of learning and buying a car and paying for insurance and gas and maintenance

dapper badge
#

yeah owning a car is EXPENSIVE

pure sun
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Yeah

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The easiest solution would just be to date someone who can drive

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But my bf also cant drive D:

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So we are just double useless

maiden bear
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My roommate drives and has a car

pure sun
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Aww yeah

maiden bear
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started to really appreciate that two days ago

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because he ain't here atm

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and i was shopping for a party that i hosted yesterday

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carrying two of these was not that much fun

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and usually we just got them into his car

pure sun
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Oh yeah that sucks

maiden bear
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i also live on the 4th floor opencry

pure sun
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Oh no hahaha

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My grocery store is a 10 minute walk away and sometimes i buy too much and have a heavy load to carry

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But i try to just go more frewuently and buy less at a time

maiden bear
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Yeah i do the same

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but sometimes i just get the urge to buy a lot of stuff and see how well i can carry it

pure sun
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Literally me

maiden bear
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lmao

wooden flax
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Lmfao

storm sage
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BASED

wooden flax
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Kinda hyped for my permit this fall ngl

storm sage
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Okay but unironically car culture sucks

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Yay for your permit though :)

bright hill
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I'm an unironic r/fuckcars activist

pure sun
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i followed r/fuckcars before it was cool

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😎

bright hill
tawdry falcon
#

Yeah cars suck, but recommend a cool polyhedron to build with paper and explain why you think it's cool, plz KEK

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If I agree I might build it

bright hill
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Cube

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Coz it simple and cute

tawdry falcon
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Yes, but I don't want simple and cute polyhedrons, I want cool polyhedrons

tawdry falcon
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Also, I already built lots of cubes

ocean thorn
#

guys, i apreaceate all the helping you guys do, just try to explain as much as much in plain english while being specific about it. sometimes its hard to understand if one says something not entirely vague but a little vague. or one uses mathmatical notation or a=b something, while i understand that a=b, sometimes idk what to do with a=b if i haven't understood you well. thats all, apreciate it

lunar spear
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You not gonna like me

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appreciate

ocean thorn
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Legend has it, @tawdry falcon is still typing to this day

wicked ore
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No explanation needed

tawdry falcon
# ocean thorn guys, i apreaceate all the helping you guys do, just try to explain as much as m...

In most cases, people who help only give hints about how to solve a problem, or show how to solve a more general type of problems
You might not know what the person helping you takes for obvious and it's ok to not understand something instantly, it happens all the time when I ask for help. You should immediately ask them what they mean, to help them help you
Also, keep in mind that people who help do it out of love for maths and/or teaching (in fact, everyone does this for free), and no one will intentionally try to make things harder for no reason

tawdry falcon
# wicked ore Octahemioctahedron

That's a good one, seems tough to build with paper only.
Looks like it's made with triangles only, super cool!
Also, bonus points for cool name
:o all the triangles are the same size and form pyramids 🤯

wicked ore
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Yep

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I found it in an origami book so it’s certainly possible

tawdry falcon
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Yes I'm working on it ^^

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If I get it right I'll post it

wicked ore
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Nice ok

tawdry falcon
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I messed up some folds Some happy little accidents occurred, but I'm pretty sure hopefully I can get it right

rustic island
#

,calc 2 * 2^1023

fathom swallowBOT
#

Result:

Infinity
rustic island
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,calc 1.99999999999999 * 2^1023

fathom swallowBOT
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Result:

1.7976931348623e+308
rustic island
#

@hollow sundial for science ^

bright hill
#

,iam dying

fathom swallowBOT
#

Gave you the studying! selfrole.

chilly hull
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,calc 2^1024-1

fathom swallowBOT
#

Result:

Infinity
chilly hull
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,calc (2^1023)+((2^1023)-0.01)

fathom swallowBOT
#

Result:

Infinity
chilly hull
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,calc (2^1023)+((2^1022))

fathom swallowBOT
#

Result:

1.3482698511467e+308
tall badge
chilly hull
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oh yeah

lunar spear
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and nice

tawdry falcon
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Guys I did it ^^ It's beautiful (There's an ugly side, but I won't send it ahah)

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(thanks @wicked ore for the suggestion)

wicked ore
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Bro wth

#

Did you do that all by yourself

tawdry falcon
#

Yes! I copied a net I found online, if anyone wants it I can send it

wicked ore
#

Wow

#

That’s amazing

#

It looks great, well done dude

wooden flax
#

Lmfao

#

Looks amazing

pure sun
#

thanks for sharing

tawdry falcon
#

thanks guys

deep mango
#

That is cool

bright hill
#

this is sick

#

very well done catbread

tender tulip
#

Czesaro polyhedron

honest veldt
#

Very pretty object, well done nonna

neat lintel
#

for this server, they should have a integration emoji

sturdy surge
#

I'm having a probability problem. Here it is.

There is a game that I am currently playing in which there exists different elements that can be controlled by a player. The "elements" are chosen by the 100 rolls, given to a player upon debut.

The chance of rolling spatial is 0.01% per roll. What are the chances of rolling spatial with the full 100 rolls?

Is it 1%?

peak tide
#

probability of not rolling spatial in 100 rolls is 0.9999^100 = 0.990049338691372

ancient flame
peak tide
#

therefore probability of rolling spatial at least once in 100 rolls is 1 - 0.990049338691372 = 0.00995066130862809 = 0.995066130862809%

#

so, very close to 1% but not quite exactly

#

this assumes of course that the rolls are statistically independent

hollow sundial
#

@austere hazel how goes school?

austere hazel
#

Frustratingly frustrating

#

Deserves to be said twice

#

That said i've had a bit of fun with the imc recently so there's that

hollow sundial
#

What stuff are you teaching/learning

#

Oh you were in Bulgaria?

austere hazel
#

Teaching, sets, logic, how to prove things, differentiation, integration, DEs

austere hazel
#

Trained a few who did go

hollow sundial
#

Oh nice

#

You competed vicariously

austere hazel
#

Is it really competing vicariously if i'm on the side of the ones making questions?

hollow sundial
#

Oh dang I didn't know you were a writer

#

Question maker?

austere hazel
#

I've always liked making questions better than solving them

hollow sundial
#

Takes a special evil to make questions

austere hazel
#

Part of the joy is seeing how many die and how many don't die

hollow sundial
#

Do you make questions deliberately using certain techniques like differentiating under the integral etc.

austere hazel
#

I like to combine techniques

hollow sundial
#

Impressive

austere hazel
#

Whether or not they turn out to be special techniques isn't all that important

chilly hull
#

i should make a diabolical calc test before i graduate hs as a funny joke

austere hazel
#

I support, i did that in high school

#

Got someone to take it even

hollow sundial
#

There's a sucker born every minute

chilly hull
#

30 questions

austere hazel
#

Later on i made several in both math and physics and had more suckers do them

chilly hull
#

actually no

#

uh

#

10 questions

icy blaze
#

Give it to your teacher and bet 1% of your grade they can't solve it. (Then maybe just slide a quick unsolved problem into it to guarantee your victory XD)

chilly hull
#

its going to be funny

austere hazel
#

Where's the fun in that?

icy blaze
#

Heck, I would have won that 1% if I had simply asked my high school math teacher what the square root of -1 was

austere hazel
#

...what?

chilly hull
#

i

austere hazel
#

I was taught that in middle school

icy blaze
#

I'm not kidding. I ABSOLUTLY COULD NOT convince my math teacher that imaginary numbers were a real usable concept in math

austere hazel
#

And right after that lesson i went to ask what's something raised to a complex power

chilly hull
#

how

#

idk about raising something to a complex power

#

but how do you not know sqrt(-1) as a math teacher

icy blaze
#

Complex powers generally just represent rotations in the complex plane, don't they? I haven't followed it too much, I'm more of a prime numbers guy than that stuff XD

austere hazel
#

Yes, but i didn't know that back then

storm sage
#

in general, multiplying by a complex number means a stretch and a rotation

icy blaze
#

Yeah, that one I knew

storm sage
#

like for example if you multiply by 2, everything gets stretched by 2

austere hazel
icy blaze
#

The funniest part is

#

I literally showed her that the TI-84 calculators we used could work with complex numbers

#

And she still didn't believe that they meant anything at all XD

storm sage
#

RIP.

peak tide
austere hazel
#

Is that how it works these days?

hollow sundial
#

Hahahahahhahahahahahahaa

#

God no

icy blaze
#

Honestly, I'm not sure what worries me more- people who don't have certification to work the job they do, or people who DO have the certification and STILL have no idea what they're doing

hollow sundial
#

America K-12 education is pathetic

chilly hull
#

ok how do i create a document with latex

austere hazel
#

One of the reasons i'm thankful i'm not in America

chilly hull
#

like

#

looks like it was made in latecx

icy blaze
#

I'm Canadian, so it doesn't apply to me anyway XD

dreamy siren
#

People who teach sometimes get these sticks up their asses that they know everything there is to know in a subject and can't be questioned, its probably not that she doesnt know its i but rather that she refuses to believe concepts outside her expertise are more than little whimsical fantasies

austere hazel
peak tide
icy blaze
#

I almost feel like it was a waste of my love of random math to write a whole paper on comparing the distributions of numbers with different amounts of prime factors with each other for the final in that class

austere hazel
#

Oh?

icy blaze
#

Because I know it went way over her head lol

austere hazel
#

I might be interested in having a look, if you don't mind

icy blaze
#

Ehhh, well it was actually very flawed

austere hazel
#

I have an ongoing side project i'm stuck in that seems to need a study of prime factor behaviour

icy blaze
#

The issue was, I based the analysis off of data from a program I made, but the program didn't properly count the number of factors a result had. BUT- I've done lots of other cool things with primes, if you want to chat about those lol

austere hazel
#

Why not, might be helpful

#

But erm, this seems like it needs more attention than i can afford today, so maybe tomorrow :/

icy blaze
#

I've actually been coding a prime factoring algorithm using my newest ideas. And alright

austere hazel
#

gonna add you as a friend so i can pm you~

icy blaze
#

Just ping and/or PM me whenever you want to know about it lol. It's nothing groundbreaking- at least not yet. But it's still a neat way to visualize them

#

ok

austere hazel
#

yeah, i'm not looking for groundbreaking, i'm looking for sufficient to get past that block i have

#

my main stuff is in FA and has little to do with primes

icy blaze
#

I see. Yeah, I just do math as a hobby, but I'm actually studying computer science lol. It's definitely nice whenever I need to make a program to do all the work for me XD

austere hazel
#

luckily (or unluckily) for me, everything i have to do is on paper xD

#

no computer coding necessary!

icy blaze
#

Yeah, there are definitely benefits to that kind of work. I mean, TECHNICALLY no coding is required for what I'm doing either

austere hazel
#

unless you count TeX as a coding language, which...i don't

icy blaze
#

I can just prove it much easier (Though, I suppose "prove" isn't the right word. Rather "apply the proof")

austere hazel
#

some days though, i feel like coding might have been a better option

icy blaze
#

Depends why you want it. I like to code video games, and want to make them for a living- it's just convenient to have for math as well

austere hazel
#

that reminds me i still have a visual novel scenario to write

#

i'm not worrying about the coding part until we get to said part

icy blaze
#

Makes sense. Python is a really easy language to learn, and has libraries available to make visual novels in (It's what Doki Doki Literature Club was made in, at least the original)

chilly hull
#

what else do i add

icy blaze
#

Not enough nested trig functions

austere hazel
#

please, why restrict yourself to sin and cos?

storm sage
#

chain rule is easy though

deep mango
storm sage
#

quotient rule is where it's at

austere hazel
#

why not tan, cot, sec, csc, sinh, cosh, etc

chilly hull
#

im making that question to waste time

austere hazel
#

you should put in harder questions

#

i'm not a fan of waste time questions

deep mango
#

Giv em a nested exponential or something

#

Make them do double log differentiation

austere hazel
#

integrate something that needs a non-obvious sub

icy blaze
#

besides, if you really want to waste time, just ask them to write the first 100 digits of some ridiculous fraction using long division. (I know that isn't calc, but like-)

storm sage
#

have them differentiate x x-arrow x

austere hazel
#

integrate something that needs induction

chilly hull
#

honestly i dont think i should make this test yet tbh

#

i dont think im at the point where i can devise diabolical questions on calc

honest veldt
#

devious calc 2 😈😈😈

dreamy siren
#

Get some 2d functions in there and throw in indicator functions, those will really fuck with people

icy blaze
#

Eh, just ask them what sqrt(-1) is. Worked for me XD

chilly hull
#

bro even i dont know what indicator functions are

#

ok yeah im not making it yet

#

not the time

dreamy siren
#

They indicate a point is a part of a set. 1 when yes 0 when no.

swift sinew
#

ryc, i-

deep mango
#

Hi alex

#

Did you enjoy the bb24 prejury

#

I did

#

I havent been paying a ton of attention this week

swift sinew
#

I’m two weeks behind cryingjordan

austere hazel
chilly hull
#

i am going to make an immensely cruel calc 1 test on april

hushed turret
#

big brother?

swift sinew
#

I haven’t even seen ||pooch evicted||

chilly hull
swift sinew
#

I tried watching it on my tv but my housemates were being obstructive and I don’t have another way to watch it

deep mango
#

What???

icy blaze
#

Even I saw that. And it was the only clip of the only episode I've watched this season XD

swift sinew
#

I guess I could watch old episodes but that is so much time that I don’t have

blazing pawn
#

You dont have another way to watch it...

deep mango
#

You are

#

Light years behind

blazing pawn
#

it is literally 2022

deep mango
#

Ok just

#

Please please watch the week 3 veto and eviction episodes

#

You dont need to watch anything else

#

But those are 2 very very good episodes

swift sinew
#

Ok, I will do that - p sure I’ll get hooked from them

deep mango
#

Unless you know what's been happening since then

swift sinew
#

I don’t

deep mango
#

It's very fun bb

swift sinew
#

This better be worth it. I watched the entirety of last season in 2 days last summer, so I do have the stamina

deep mango
#

It's just 2 good episodes

blazing pawn
#

grad students: "yeah we're really busy, its nothing like undergrad"
grad students:

swift sinew
#

Well yeah but it’s never just 2 episodes

deep mango
#

Well sure

#

But like

chilly hull
#

how much harder is grad

#

compared to undergrad

deep mango
#

Uhh i mean

swift sinew
#

I’ll put it on tomorrow morning

deep mango
#

It sucks! We're all dying! Wah wah

chilly hull
#

on god?

deep mango
#

Yep

icy blaze
blazing pawn
deep mango
#

Grad school gives you more free time but also you spend a lot more time doing harder math

#

And doing harder math takes more energy

chilly hull
#

so is like

icy blaze
#

I didn't have that question in my quizes. Must only be in some curriculums XD

chilly hull
#

you have more free time

blazing pawn
#

Not if you are fueled by rage and impotence

chilly hull
#

but the time you dont have free time is

blazing pawn
#

then it just leads to a feedback loop

deep mango
#

It's a lot about stamina and self control / managing your decisions well I would say

#

Lol

burnt dune
#

SA simpleart

velvet dagger
#

Main shtick about grad vs undergrad is local vs global pressure

#

Undergrad has a lot more structure

#

You have your weekly psets, you know your exam dates, at least have an idea how grading will look like

#

So doing that and just "living well" is kinda the correct course of action in undergrad. Maybe you have to think a little bit about what to do during summers for the sake of future grad school or career

#

Grad school starts off slightly like that but more chill

#

But then eventually it becomes a lot of global pressure but less local pressure/structure

#

Obv if you have a good advisor there's still a ton of guidance

#

But it's more like yeah make yourself look impressive enough to get good jobs by the time you're out, plus some mix of worrying about balancing prepping for possible academia and industry

#

There are some deadlines along the way but you have to have a lot more self control

#

There isn't a pset worth n% of your grade that's due this Friday, there's an advisor meeting which you should prepare for but which you can kinda wing if you're lucky and sometimes when you're not feeling it you take that option.... more times than you should

deep mango
#

This is a very good description of it

burnt dune
#

gamed enta ya daminark

errant ridge
icy crag
ocean thorn
hollow sundial
ocean thorn
#

I understand, appreciate, and respect all the amazing work you guys are doing. It was more about voicing the differences in levels of math we have in this server.

ocean thorn
# ocean thorn really think about it. really just. dream about this. because almost everyone wh...

And this statement was supposed to be a joke to emphasize the idea of the 'expert blind spot', the idea that since experts work on something for so long that many things are obvious to them compared to the layman.
The statement "dream about it" comes from how i feel sometimes, when i am between the phase of sleep and being awake, and in this dream like thinking; this is the phase where reality sort of breaks down in my mind. And everything starts to appear strange. Where normal and mundane things appear strange and don't make any sense. So assuming that it would be same with thinking about math, the parts of math that appear so normal often would appear strange in this phase.

#

Now back to doing math

dapper badge
# dapper badge but I will update all of my fans on how it goes

I am here to provide my update: I fell and died several times, but ultimately I survived. Overall I had a really great time and I'll absolutely go again when I have the chance. After we finished rock climbing we also hiked up a nearby mountain. Then we got greek food for dinner. A fun day for sure

#

also my new glasses came in

#

doctor's appointment in the morning went well and soon I will be on my way to the airport

bright hill
#

daily vlogs when?

#

also, please teach me how to die

#

lol

#

ya

#

I just started reading dandadan

#

that shit is soooo good

#

Seriously, @supple flame have you seen dandadan?

#

bruh

#

that's exactly what I'm thinking right now

#

worse yet, the manga is SICK

#

holy shit, are you even living

#

wuss dat?

split island
#

Hell’s paradise fan hmmCat

#

I’ve just been there around the beginning of English serialization

bright hill
#

aww mannn

#

but the adaptation is gonna be from mappa!!

#

yohan, dis not fair

neat lintel
#

mappa is really just adapting everything huh

bright hill
#

hmm

#

it's not out yet

#

is that ok?

#

bet

full isle
#

adappa

bright hill
#

ah shit, I didn't take this into account

#

yohan, I'm gonna take my sweet fucking time with this one

#

don't you DARE spoil anything

#

bruh, my classmates spoiled so many shows for me

#

one I was talking to one of my classmates and I just heard about shigatsu no uso

#

so I was like, do you know this show

#

and I barely finished talking and he was like ||"you know the blonde dies by the end, right?"||

#

I'll never forgive them sadcat

#

I liked that show so much sadcat

misty lake
bright hill
#

you can just read it from mangaplus, dumbo

#

they released all chapters for (all?) their mangas for free

#

even MY internet lets me read manga

#

jeez

neat frost
#

good morning rycie bycie!

deep mango
neat frost
#

Ryc have I complained to you about B trees yet?

deep mango
#

Not red black trees?

bright hill
neat frost
#

No B trees

#

Stupid little shits

deep mango
#

What is B?

neat frost
#

Not specified

deep mango
#

What is a B tree

neat frost
#

Like the creators never specified

neat frost
# deep mango What is a B tree

It’s a full tree (idk if that’s what you call it, but like all the leaves are on the same level) where you have an m, and every node has a sorted list of m-1 values with m children, and in each node except the root there must be at least m/2 values

#

You can then create algorithms to ensure that this remains full

#

Or complete

#

Whatever

#

So the height is always logarithmic

#

Anyway I just knew I’d fuck up a B tree question if it was on my test, and guess what? I fucking did

bright hill
#

watching anime doesn't necessarily equal being a weeb

neat frost
deep mango
neat frost
#

Basically on my test I had to give an example 2-3 tree for a reason, and I forgot to add a fucking subtree. Like the root had 2 values and therefore should have 3 children, but I only drew 2

deep mango
#

But not whatever this lie in april thing is

bright hill
#

spy x family is barely mainstream

neat frost
#

I don’t think it would really have affected my answer, but that was like a large part of the question, and that was dumb of me

bright hill
#

BUT YOUR LIE IN APRIL IS, YOU UNCULTURED HEATHEN

neat frost
#

And the question was worth 12 points

deep mango
#

Slurp

neat frost
#

Yes

deep mango
#

If you dont get an A on the test

neat frost
#

RYC

deep mango
#

Call me and I'll beat them up

neat frost
#

ITS FUCKING B TREESSSSSS

#

I CANT

#

AHHHAHAHAHHHH

neat frost
deep mango
#

Now let me tell darq whats what

neat frost
#

I fucking despise b trees

deep mango
#

THAT SHOW IS FOR. WEEEEBS.

neat frost
#

Now Imma wait for loch to return so I can complain to him

deep mango
#

Yes loch is more of an adult isnt he

neat frost
#

Also ryc I’m home and I have no clue where my family is

neat frost
deep mango
#

Probably all getting ice cream without you

neat frost
#

So he can be like “oh don’t worry slurp that wasn’t a big deal, you’ll probably only lose like maximum 5 points”

#

And I’d believe him cuz he’s a CS dude

#

I just need the reassurance

deep mango
#

Oh dont worry slurp that wasnt a big deal, you'll probab

#

Fuck

#

I'm kind of a CS dude

neat frost
#

Ryc are you admitting that you’re a CS dude?

#

Omg he is

deep mango
#

I'm an everydude

bright hill
#

including an anime dude?

deep mango
#

You can be a math dude

#

I have no qualms with that

fringe needle
#

Anyone know how long you should wait for a mod mail request?

neat frost
#

I told you, you should’ve spammed ryc

fringe needle
#

I’m no spammer

deep mango
#

Oh yeah

#

One sec

#

I'm just checking in one more time and then we will get back to you

fringe needle
#

Thanks

analog salmon
#

Not a weeb btw

fathom swallowBOT
bright hill
#

@ancient flame I don't think your definition works for finite sets

ancient flame
#

oh fuck

bright hill
#

besides, 0*inf is undefined

ancient flame
#

so then how would you show that $\int_{[a, b]}=\int_{(a, b)}$?

fathom swallowBOT
bright hill
#

by using a stronger definition?

ancient flame
#

oh like lebesgue shit?

neat lintel
#

lowmath discovers measure theory

bright hill
#

lol

ancient flame
#

aw fuck

#

what like the singleton has measure 0 or some shit

#

yeah

#

idk

bright hill
#

monkey oh

#

your definition is wrong in the first place

#

you don't multiply by 1/N, you multiply by (b-a)/N

ancient flame
#

fuck im dumb

#

I always make that mistake

bright hill
#

I should've noticed that sooner myself lol

ancient flame
#

icic

frail lagoon
#

Yo

ancient flame
#

alright thanks everyone

#

hi

neat lintel
frail lagoon
#

Well Riemann integration would typically be defined for real-valued functions anyway right so xd

#

But sure stuff like you can define some sequence going to infinity and keep everything else the same

ancient flame
#

lol tterra mutes chill

frail lagoon
#

Why would you not mute chill

ancient flame
#

bc I like chill

frail lagoon
#

The proverbial cesspit

ancient flame
#

LOL

analog salmon
#

That's my proverbial cesspool

neat lintel
bright hill
#

I keep discovering things wrong with your definition opencry

ancient flame
ancient flame
neat lintel
#

i'll let you figure that one out

ancient flame
#

OH SHIT

#

LOL

#

2<1

bright hill
arctic grove
# neat lintel

Idk, mods seem to think its funny to rename their channels with higher numbers as if there are those many. shows how mature they are.

fathom swallowBOT
ancient flame
#

yeah that's not riemann integrable

bright hill
#

from, say, 0 to 1

ancient flame
#

alright yeah makes sense

#

I just had a 0 intelligence quotient moment

sleek wing
#

Meow

bright hill
#

which is nonsense

ancient flame
#

woof

open aspen
#

That hurt my head to read

bright hill
open aspen
#

It was deleted

bright hill
#

oh

hollow sundial
fathom swallowBOT
#

riemann

fading moon
#

is there a machine learning channel here?

deep mango
ancient flame
#

gmod

wild lantern
#

Jee-mawd

deep mango
#

what

#

i've always pronounced it "guhMAHD"

#

but like

#

one syllable

wild lantern
#

Not like the game?

#

garry's mod <-> "Jee-Mawd"

deep mango
#

i didn't think they were related?

#

you know how there are gnu's

ancient flame
ancient flame
#

it doesn't come from the game tho

deep mango
#

what

ancient flame
#

it originally came from my irl name, and after being transformed and convoluted over the years it became gmod

wild lantern
#

Your real name is gregory mod realshit

ancient flame
#

ofc

bright hill
#

I did no math today

#

I feel...

#

out of my depth

vivid halo
#

I should do some math today monkey

neat lintel
#

it's okay to not do math

vivid halo
#

no

bright hill
#

no

ancient flame
#

bruh

vivid halo
#

nah like I have stuff I want to do just haven't had a good time focussing lately

bright hill
#

I went full monkey brain today bruh

#

I couldn't be productive for more than 2 minutes lol

#

nG, what math are you working on atm?

ancient flame
#

ignored

bright hill
honest veldt
#

it's fine Darq, just imagine a combination of words that look like they might possibly belong in the English language but you're not sure, and string them together

#

thats what nG would've answered with

vivid halo
vivid halo
#

I've been confusing myself with hypergeometric functions lately

bright hill
#

open problems and the like

vivid halo
#

idk the problems I'm doing aren't actually that hard once you know what's going on, it's just writing everything up clearly and organizing everything is hard

#

or like, there's a lot of annoying struggling with getting notation and conventions from different sources to match up

bright hill
vivid halo
#

ehh I mean you have to deal with this to some degree with research

#

some fields are worse than others

#

also there's some tradeoff between like, is it easier to resolve conflicts like this or just work it out yourself

bright hill
#

work it out yourself?

#

like, make up your own notation?

vivid halo
#

that and like, reproving results rather than relying on or reproducing proofs that other people have written

bright hill
#

that could be fun, I think

#

@sleek wing why the deva? lol

sleek wing
#

dev

#

because that is literally me and sometimes not on purpose

bright hill
tender tulip
#

If we have a semigroup $S$ with a partial order R such that:
$(xy)Rx \vee (xy)Ry$. Let an element p be normal if for all x and y in S
$xRp \vee yRp \Leftrightarrow (xy)Rp$. let $Nor(S)$ be the set of prime elements. Then the anti-tail of an element $x$ is $K(x) = {y \in Nor(S) : x\cancel{R}y}$. Is the family of all anti-tails a topology?

fathom swallowBOT
#

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

tender tulip
#

actually I wrote it down a bit differently

bright hill
#

mizlang, are you allergic to the advanced channels or smth?

tender tulip
bright hill
#

why were you banned lmao

tender tulip
#

not using em correctly which is fair

#

Actually I'm gonna ask something different

#

Let $G$ be an infinite-order group, and $F$ be an uncountable collection of subgroups of $G$. Is the set theoretic intersection, aka: $\ \bigcupF = {x : \forall y \in F(x \in y)} \$ a subgroup? hhhh

fathom swallowBOT
#

Mizalign
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peak tide
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any intersection of subgroups is a subgroup

tender tulip
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actually lol it is

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if x is in all of them, then so must it's inverse be in all of them

peak tide
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yep

tender tulip
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and the identity is

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now

peak tide
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usual drill with intersections

tender tulip
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what if we're considering ideals of a ring

frozen merlin
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same thing

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also same thing with closed subsets of a space

peak tide
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any intersection of "collection of sets with property P" is usually a collection of sets with property P. Sigma algebras, topologies, etc

frozen merlin
tender tulip
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ah

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The idea of a spectrum for a ring holds for any semigroup

frozen merlin
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what's the analogue of prime ideals?

tender tulip
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We just say for a semigroup $S$, an ideal is a subset $X$ of $S$ such that for all elements of $S$, if either $x$ or $y$ is in $X$, then it's product is in $X$. We say an ideal is normal or prime if this is biconditional.

fathom swallowBOT
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Mizalign

tender tulip
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shit, gtg

frozen merlin
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do you want your semigroup to be commutative?

tender tulip
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Why does it matter

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i’m referring to two sided ideals here btw

frozen merlin
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the structure of ideals in rings is much nicer when they are commutative

tender tulip
frozen merlin
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true but I haven't heard of spec in non commutative algebra (maybe it does exist, not sure)

tender tulip
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i think the set of prime ideals that do not contain a given ideal are elements of a topology of all of the aforementioned sets

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it just happens to coincide

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technically, the product of ideals is a product, so there’s a semigroup of purely ideals

storm sage
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me when I read a proof: oh yeah this is super obvious
me five seconds later when I try to remember the reason: uhhhhhh

swift sinew
bright hill
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just for like 10-15 minutes

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I also do a writeup for particularly tricky/unintuitive proofs

full isle
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you can complete the semigroupnto a group ig

dapper badge
# tender tulip ofc, it still generalizes tho

even ignoring desired topological properties, there are a couple of papers I've come across that illustrate why naive generalizations of Spec to noncommutative rings sorta just don't work