What's something math related that confused you for a while

cardinalities

>ever being confused by anything
lol maybe if your a brainlet
Also what the fuck are these long-legged, green characters I keep seeing posted here?

in b4 e^iπ = 1

>>8915777
What confused you about counting how many things are in a box?

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

>>8915790
>all cardinalities are countable
you seem confused

>>8915794
a set either has a finite number of elements or an infinite number of elements.

What is there to be confused about?

>>8915805
>grouping all infinities together in a discussion about cardinalities
are you sure you're not confused?

The fact that an infinite sum is just the limit of a sequence and not an actual sum of infinite terms.

>>8915805
Nigga N is infinite but you can still count dat shit, real talk ma nigga

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>>8915811
I didn't group all infinite together though, i said sets are either finite or infinite, that doesn't entail that there aren't infinite sets larger than other infinite sets for the same reason saying sets are finite doesn't entail some finite numbers aren't larger than other finite numbers.

>>8915811
BTFO


Nice one Op.

Pythagorean theorem, I saw a proof of it with a square and it made a lot of sense

>>8915823
but we're talking about cardinalities, where the vast majority of the interest in studying them comes from the intricacies and counterintuitive results that come from having a variety of infinities, like the continuum hypothesis, space-filling curves, etc... saying 'a set either has a finite number of elements or an infinite number of elements' misses the point of cardinalities entirely

cantor's work wasn't controversial for nothing, whether it was important mathematicians like kronecker who literally didn't believe his results or philosophers like wittgenstein who dismissed his work entirely

>>8915778
You sound confused.

infinite sets, functions, real numbers and angles in trigonometry are problematic concepts which can't be taken for granted.

Group Actions

I was actually drunk as shit

>>8915770
limsup made more sense to me when i saw the definition that says limsup is the supremum of the set of cluster points.
>>8917593
can you explain that shit to me anon. i still dont fully get it.

the differences between pilot study and pretest in psychological research

>>8915778
>your a brainlet
>your
The irony

>>8915770
Factoring. I skipped class when we were learning it and was confused as fuck by it until I got to college.

>>8915793
nothing confusing about this

>>8915812
that's not confusing

>>8915839
This and the reason why pi is 3.14...

>>8919467
that's sad

>>8919508
>addition is commutative until you add too many things together xD

>>8919543
addition is commutative no matter how many things you add. you can't add an infinite number of things

>>8917593
>>8917615
a gorup action is just a group element acting on something. what's so hard about that

>>8915770
Laplace Transforms. I blame the EE order of Laplace Transforms -> Fourier Series -> discrete/continuous Fourier Transforms -> Z Transforms.

>>8919467
This for me too. In HS, whenever the factoring of polynomials came up, the teachers all acted like it was something you were just supposed to "see". I took until first year undergrad until I learned that all you need to do is find the roots of the polynomial.

>>8915770
Lagrange Polynomials

>>8915770
Mathematical Induction

>>8915770
P=NP

Finally figured that shit out!

>>8915770
u substitution

>>8919659
Care to share the proof for us all to see?

>>8919662
This has to be bait.

Banach–Tarski paradox

>just kidding I still don't understand it

>>8920716
is quite simple

u l r d d l u r u d u l r d r l u d r r u l u d r

now there are two balls

>>8920716
just think of it like mitosis

>>8915812
How the fuck is that confusing?

>>8915770

How to look at a differential equation and how to realize what method to use without going through EVERY method (would take forever on an exam)

took many Ds and Cs on exams/quizzes and long sleepless nights of deciphering the book to finally figure it out

The sum of all primes is -1/12

>>8920716
To put it roughly, you take all the constiuent elements of a ball and then manipulate them such that they make up a whole nother ball

>>8919559
i dont get the homorphism definition.

Stoke's theorem, mainly the concept of curl in R3

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Grassmann numbers (currently doing QFT)

Why the fuck is the derivative and the integral defined the way it is and why are they the same??

>>8920774
Mind sharing what you figured out?

>>8915770
Equivalence classes. But I think it had a lot to do with not understanding the definition of the notation.

>>8915770
Homological Algebra. Shit is so abstract.

One-time pad decryption

>>8915778
This

epsilon delta proofs
>>8922860
wat

>>8921072
I still can't visualize what a curl is.

>>8924033
Decrypting One-time pads.

>>8924436
oh i thought you said one-time pad encryption, my bad.

Will integral calculus ever not fuck me around?
How are people good at it? Are they just very smart?

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>>8915778
>mfw brainlets get confused about things
Such plaebeians, unlike enlightened gentlesirs such as myself.

>>8924035
take a wheel/turbine/fan and place it into the vector field at the point r. does the wheel start spinning? if so, there is a non-zero curl at the point r

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>>8915778
>Also what the fuck are these long-legged, green characters I keep seeing posted here?
kek idk either, is it from a cartoon or something?
maybe those books like pic related?

>>8925170
Practice makes perfect, anon

>>8915770
I was always a straight A student in math but the only topic I struggled with was Volume by Revolution
I got a 100 on each test except for the one with the volume question because the cross section stuff didn't make sense
Though after summer break and coming back to school it's so intuitive and second nature and feels good

>>8926480

A turbine and a fan will spin in a velocity field of all parallel, unidirectional vectors - if placed perpendicular to them.

>>8915770
injectivity, surjectivity and bijectivity.

>>8919512
it is if you interpret it as an actual sum and not a limit

>>8919467
>me too
FUUUUCK I'm such a disgrace

>>8919587
what made it click?

>currently stuck, probably has something to do with my terrible algebra skills

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>>8920774

>>8921394
i second this, lets help each other because we're all on 4chan together

>>8922194
mind sharing?

>went over it last week in class, still have no idea other than it's vaguely connected to power sets, except you just start making the power sets at whatever element you want to make an equivalence class for

>>8919398
how can you be so fucking stupid to miss the irony in the post you are replying to? Or am I being reverse trolled?

>>8915844
BLOWN
THE
FUCK
OUT

The definition of a limit in category theory. Feels so good now though.

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>>8915770
y=ax + b
being translated by

And also differentiating more than once, when I learned about image processing and how rate of change applied recursively makes sense. Or at least a tiny bit, I am a bit confused still, but differentiating once and twice is not magic to me anymore.

>>8915770
The covariant derivative.

>>8921281
I was so hyped about them when I first saw them

>>8928137
Not him, but think of a ladder

How do you know you can climb a ladder?

Well, first you have to know if you can climb on to the first step from the floor

Now, imagine you're mid ladder. Given that you were already able to get to the middle of the ladder, can you climb onto the next step?

Since we've shown we can climb the first step, and that if we're mid ladder, we can climb onto the next step, then this shows we can climb onto the second step. But in turn this means we can climb onto the third step, etc.
So to prove sum of integers is [math]1+2+3+...+n=\frac{n(n+1)}{2}[/math], we first have to show we can get onto the first step. The sum of the first integer is [math]1[/math], and [math]\frac{1(1+2)}{2}=1[/math], so we got onto the first step.

Now imagine we can climb onto the [math]n[/math]th step, ie: we know for some [math]n[/math], that [math]1+2+3+...+n=\frac{n(n+1)}{2}[/math]. So [eqn]1+2+3+...+n+(n+1)=\frac{n(n+1)}{2}+(n+1)=\frac{n^2+n+2n+1}{2}=\frac{(n+1)(n+2)}{2}[/eqn]
Which is the same as [math]\frac{n(n+1)}{2}[/math] but with [math]n+1[/math] instead of [math]n[/math]. So if we're on the [math]n[/math]th step, we can climb onto the [math](n+1)[/math]th step. So if we're on [math]1[/math], we can get to [math]2[/math], so we can get to [math]3[/math], etc...

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>>8927978
will it though

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>>8928362
okay so you just substitute n+1 for n, then manipulate the equation algebraically until it looks like the LHS?

pretty basic shit and not really as much understanding anything as noticing redundancies in some formula listings

[math]ln(\frac{x}{y}) = ln(x\frac{1}{y}) = ln(x) + ln(y^{-1}) = ln(x) - ln(y) [/math]

>>8915844
puttin this man into retirement god damn

>>8929104
yeah, but also works for inequalities, integrals, divisibility,etc

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innie dash outie dash innie

>>8930328
the chain rule

>>8930331
f'g + g'f

faggot + his gf

product rule

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>>8930353
>the faggot and his gf

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bump

>>8919871
le margarine is twoo smol xdddd