/sqt/ /qtddtot/ - stupid questions thread

[Anonymous No.15169850]

Formerly >>15149490

>what is /sqt/ for?
Questions regarding maths and science. Also homework.
>where do I go for advice?
>>>/sci/scg or >>>/adv/
>where do I go for other questions and requests?
>>>/wsr/ >>>/g/sqt >>>/diy/sqt etc.
>how do I post math symbols (Latex)?
rentry.org/sci-latex-v1
>a plain google search didn't return anything, is there anything else I should try before asking the question here?
scholar.google.com
>where can I search for proofs?
proofwiki.org
>where can I look up if the question has already been asked here?
warosu.org/sci
eientei.xyz/sci
>how do I optimize an image losslessly?
trimage.org
pnggauntlet.com
>how do I find the source of an image?
images.google.com
tineye.com
saucenao.com
iqdb.org

>where can I get:
>books?
libgen.rs
annas-archive.org
stitz-zeager.com
openstax.org
activecalculus.org
>articles?
sci-hub.st
>book recs?
sites.google.com/site/scienceandmathguide
4chan-science.fandom.com/wiki//sci/_Wiki
math.ucr.edu/home/baez/physics/Administrivia/booklist.html
>online courses and lectures?
khanacademy.org
>charts?
imgur.com/a/pHfMGwE
imgur.com/a/ZZDVNk1
>tables, properties and material selection?
www.engineeringtoolbox.com
www.matweb.com
www.chemspider.com

Tips for asking questions here:
>attach an image (animal images are ideal, you can grab them from >>>/an/. Alternatively use anime from safebooru.donmai.us)
>avoid replying to yourself
>ask anonymously
>recheck the Latex before posting
>ignore shitpost replies
>avoid getting into arguments
>do not tell us where is it you came from
>do not mention how [other place] didn't answer your question so you're reposting it here
>if you need to ask for clarification fifteen times in a row, try to make the sequence easy to read through
>I'm not reading your handwriting
>I'm not flipping that sideways picture
>I'm not google translating your spanish
>don't ask to ask
>don't ask for a hint if you want a solution
>xyproblem.info

[Anonymous No.15169869]

>>15169850
Unanswered questions:

Maths questions:
>>15152957
>>15155374
>>15156071
>>15163140 [Yes. Truncate the digits.]
>>15164855 [I don't remember what's this notation in algebra anymore lmao.]
>>15167771
>>15169227

Engineering questions:
>>15150459

/g/ questions:
>>15160147
>>15160002

Stupid questions:
>>15151882
>>15152490
>>15152758
>>15154439
>>15154765
>>15155890
>>15157178
>>15157590 [This is here because "higher mathematics" is a disgusting buzzword.]
>>15161067
>>15161717
>>15164830
>>15166963
>>15167719
>>15168669

[Anonymous No.15169877]

You are a homosexual pedophile who masturbates to children's cartoons

[Anonymous No.15169882]

How do I become smart?

Serious answers only

[Anonymous No.15169955]

If every method for solving antiderivatives is just streamlined guess and check, how do calculators and computers do it? They can't "guess and check" right? Not referring to AI.

[Anonymous No.15169993]

>>15169955
https://en.wikipedia.org/wiki/Risch_algorithm?useskin=vector

[Anonymous No.15170142]

Where can I find challenge problems for E&M? I'm trying to study for an exam and most of the stuff I've found online is easy shit.

[Anonymous No.15170394]

Does there exist any inequality where LHS < RHS and LHS > RHS are both possible depending on the circumstances, but LHS = RHS is never possible?

[Anonymous No.15170459]

>>15169869
>[This is here because "higher mathematics" is a disgusting buzzword.]
fuck you

[Anonymous No.15170494]

>>15169882
do lots of IQ tests

[Anonymous No.15170517]

>>15170394
LHS = √1
RHS = 0

[Anonymous No.15170741]

>>15170517
Most generally |x| and 0, with x!=0 of course

[Anonymous No.15171035]

An algorithm runs in a number of steps t(n) that is a polynomial function of its input size n. Moreover, the time taken for each step also depends on n, so let's say that on input size n, each of the t(n) steps runs in time [math]O(n^{c(n)})[/math] for some function [math]c: \mathbb{N} \to \mathbb{N}[/math] fixed and known.
Without any further constraints on the function c (e.g. it may diverge to [math]\infty[/math]), is the algorithm still in P? If not, what would we need to impose for that to happen?

[Anonymous No.15171085]

Is it possible to develop a turing test machine that can 100% accurately detect the machine that is designed to 100% pass the turing test?

[Anonymous No.15171098]

>>15169850
what?

[Anonymous No.15171109]

>>15171098
What is 25 percent of 40 percent?

[Anonymous No.15171150]

>>15169869
you forgot >>15163049

[Anonymous No.15171159]

I apologize, because I have a truly retarded question

In quantum mechanics, is spin a continuous state as long as you keep observing it? So if you measure an Up spin on a particle, can you watch it spinning Up for a period of time?

[Anonymous No.15171169]

>>15171109
well, 10, but if the whole is the same for both percentages, wouldn't 10 be 10% of the whole anyway? it only makes sense to be 25% if the whole suddenly becomes 40%, but then 50% of the whole "40%" would be 20%, which is 25% less than 40%

[Anonymous No.15171173]

>>15171169
>which is 25% less than 40%
sorry, I meant 20% less

[Anonymous No.15171185]

>>15171169
>wouldn't 10 be 10% of the whole anyway
Yes. But it's 25% of the 40%.
"The same whole" is only meant to indicate that the percentages are all in reference to the same total amount, rather than, say, 40% of 40 feet and 50% of 50 feet. The only thing that matters when comparing percentages like this is what they are relative to each other, not to 100%.

[Anonymous No.15171196]

>>15171185
>"The same whole" is only meant to indicate that the percentages are all in reference to the same total amount, rather than, say, 40% of 40 feet and 50% of 50 feet. The only thing that matters when comparing percentages like this is what they are relative to each other, not to 100%.
So in the exercise in the pciture, the answer to "c" would be 67%, not 62.5% - 37.5% = 25%, right? Since relative to 37.5%, 62.5% is 67% more?

[Anonymous No.15171201]

>>15171196
Yes, exactly.
(Well, technically it'd be 66.66...%, but I assume you're aware of that fact.)

[Anonymous No.15171211]

>>15171196
>>15171201
I will also note that the wording can be important, because, yes, this concept can be a little ambiguous.
If the question had been, for example, "How much more of the punch is juice than soda?", then it would just be 25%, since it's made clear that it's in reference to the amount of punch rather than the amount of soda.

[Anonymous No.15171217]

>>15171211
i think it's because of this

[Anonymous No.15171231]

>>15159930
I often do this as follows:
[math]\begin{align*}
x &=
\begingroup
\renewcommand*{\arraystretch}{0.5}
\setlength\arraycolsep{2pt}
\prescript{a}{b}{
\begin{bmatrix}
1 & 2 \\
3 & 4
\end{bmatrix}^c_d}
\endgroup
\end{align*}[/math], defining a group wherein I change spacing stuff. Not sure if you can view the latex source code somehow so I'll just paste it here too (it's very ugly imo).

\begin{align*}
x &=
\begingroup
\renewcommand*{\arraystretch}{0.5}
\setlength\arraycolsep{2pt}
\prescript{a}{b}{
\begin{bmatrix}
1 & 2 \\
a & b
\end{bmatrix}^c_d}
\endgroup
\end{align*}

See also the prefix command from the mathtools package.
>>15160002
Why not just a table? that seems like what you are trying to mimic with the matrix.

>>15169227
That would depend on the set of functions, but generally it's just like any other set in some topological/metric/nv space. Show its complement is open / any converging sequence has its limit in the set / ...

>>15167719
No one knows, really. A data scientist will probably use some form of AI in the (near) future, to tell it to make some type of plot from certain columns with styles similar to some other plot. I don't think it will be automated before AGI because domain knowledge is giga important.

[Anonymous No.15171236]

>>15171231
yeah the mathjax looks borked to me.

[Anonymous No.15171328]

Statistically, how do I find love?

[Anonymous No.15171329]

>>15171217
I think I need to read the chapter again, I'm starting to understand what it really means to say 62.5% is 66.66...% more than 37.5%. It means if you have 37.5% of some whole, then divide it (the 37.5% of the whole) in 100 equal parts, if you add those 100 parts to another 67 parts of the same area each, you will get roughly the same total area than if you took 62.5% of the same whole and divided this (the 62.5% of the whole) in 100 parts.

To say 37.5% is 40% less than 62.5% means if you take 62.5% of the whole, then divide it in 100 parts, if you 40% of those 100 parts you will get the same area ad if you took 37.5% of the whole.

Now I need to understand why if a percentage A is 20% more than a percentage B it doesn't meat B is 20% less than A, using the same fraction reasoning.

[Anonymous No.15171335]

>>15171329
>Now I need to understand why if a percentage A is 20% more than a percentage B it doesn't meat B is 20% less than A, using the same fraction reasoning.
It's the same idea, but in reverse. If you take 62.5% of the whole, split that into 100 equal parts, and consider only 60 of those parts, those 40 will make up the same area as 37.5% of the original.

[Anonymous No.15171337]

>>15171329
>Now I need to understand why if a percentage A is 20% more than a percentage B it doesn't meat B is 20% less than A, using the same fraction reasoning.
Using the example we're running with:
A being 20% more than B means that you split B into 100 equal-sized parts, add on 20 more of those, and you end up with A. But if you reassemble those parts and split that into 100 equal-sized parts, they will be bigger than the parts you originally had, so removing 20 of them will not give you the same thing you started with.

[Anonymous No.15171518]

>>15169869
I figured out how to count inside a 3d shape by counting inside a 2d shape by counting inside a 1d shape by counting inside a 0d shape.

I didn't name the 0D one. The 1D radix two one I am going to call a Wolfy Maid Space because I was looking at the triangle book and I see she started with dot-lines which are black and white lines that have dots. Then computed ruled that changed the position of the dots a lot of times. The recorded all the dot-lines and ordered them by time and now it is a 2D shape and you can see the dots were drawing triangles.

The 2D radix 2 one I am going to call Coolkyousinnjya Maid Space because he drew a lot of maids in black and white and wrote dra/g/on maid.

If you take a lot of 2D Maid Spaces and out them in a time order and and put them on top of eachother you get a 3D shape that can be drawn by voxels. Or it can be used as a 2D animation. I don't know what to call this one it is a cube that has time so I am thinking call it Maid Time Cube, but I am not sure if this is a good idea or not because I like it more when something is named after a specific maid.

I only know some of the maids from Touhou and I already named things after them. Like Kurumi MaidCard or Wolfy Maid Space.

What do I call the other shapes that didn't get names? Also, I don't have an AI drawing computer and I need a lot of maids for the margins of the book and anywhere a page ends early and has whitespace. I want to put at least one maid on every page.

Will it cause problems from copyright if I go to like safebooru or something and download a lot of maids with big boobs for the margins? Is there some academic carveout that would allow me to put in the maids with getting problems from copyright because now they are educational big titty Computer Science maids?

Everything else in the book is either writing or a Computer Program I made so it can get released to CC0 without problems.

I had the question about style. I decided for now just use bmatrix.

[Anonymous No.15171534]

if I'm on a planet moving 186k miles/s through the universe will I stop seeing light. why can't a spacecraft keep accelerating to infinity if everything moves relative to each other?

[Anonymous No.15171556]

>>15169869
Water, fungus, detritus, substrate, metabolites.

[Anonymous No.15171561]

>>15169869
they serve different functions, they have different compositions
pee is liquid so the body can get rid of soluble stuff
mucous membrane need more viscous fluids to stay humid or lubricated

[Anonymous No.15171566]

>>15169869
you might wanna cite all those sources or use the [anon et al and references therein] term

[Anonymous No.15171574]

>>15171566
*also this

[Anonymous No.15171581]

>>15171556
Thank you anon for replying to old questions

[Anonymous No.15171609]

Could i get help for this set theory question: Prove the following function is uncountable: Func(N)= { f | f : N -> N}

[Anonymous No.15171755]

>>15171609
Copy Cantor's diagonal argument.
Hint: n + 1.
>>15171035
> is the algorithm still in P?
No.
>If not, what would we need to impose for that to happen?
[math]c(n)[/math] bounded is both sufficient and necessary.

[Anonymous No.15171760]

>>15171755
Why are maids from Touhou doing advanced math? What is the purpose of the Touhou Maid Mathematics Program?

[Anonymous No.15171779]

Best career path for maximum monetary gains after I get my degree? I'm an EE undergrad and the things I'm more passionate about are not career-related so I'd rather maximize profit and invest. I don't really like electronics so I've been working on my Python skills on the side, should I start getting into Probabilities and head into Data Science or are there better options?

[Anonymous No.15171791]

>>15171755
Is Set Theory of specific interest to maids from Touhou?

[Anonymous No.15171819]

>>15171337
>A being 20% more than B means that you split B into 100 equal-sized parts, add on 20 more of those, and you end up with A. But if you reassemble those parts and split that into 100 equal-sized parts, they will be bigger than the parts you originally had, so removing 20 of them will not give you the same thing you started with.
oh, i get it now, thanks

[Anonymous No.15171835]

>>15171755
Are being a vampire and being a maid somehow connected? Being a vampire and doing math? Being a maid and doing math? The ice maid doesn't seem to be a vampire and she does math too.

[Anonymous No.15172000]

I'm 28 now, thinking about the future. Any advice no matter how generic is appreciated. What kind of habits should I cultivate? What are some common mistakes that can be fixed right now or might show up in the future? What should I avoid entirely? Is there even a checklist for this kind of stuff?

Answer shouldn't be restricted just to life, math could also be appreciated. Finances, cooking, lifting, social, whatever you got. Thanks anons.

[Anonymous No.15172043]

>>15171085
no, by Rice's theorem. Any nontrivial semantic property of a program is not decidable; if it were, you would be able to build a Turing machine that solved the halting problem. See https://en.wikipedia.org//wiki/Rice's_theorem

[Anonymous No.15172105]

>>15171835
three replies to the same post is a lot, calm down

[Anonymous No.15172109]

>>15170142
jackson electrodynamics

[Anonymous No.15172130]

>>15172105
I just like it when maids are doing math on the internet.

[Anonymous No.15172184]

This is my problem: I want to find an incomplete metric space in which the Banach fixed-point theorem is true. I know that the set

[math]M = \{(x, \sin(1/x)) \mid x \in\, ]0,\, 1]\} \subset \mathbb{R}^{2}[/math]

with the Euklidean metric is an incomplete metric space that would satisfy this condition; meaning in [math](M, |\cdot|)[/math], the Banach fixed-point theorem is in fact true. Here is how I was trying to show it:

>(1) show that the image of a contraction f: M -> M - called K - is a compact subset of M
>(2) restrict the domain of f from M to K
>(3) K is complete, since it is compact
>(4) apply the Banach fixed-point theorem

My problem is with step (1). I don't know how to show that K is compact. Do you have any ideas how I could show this?

[Anonymous No.15172187]

>>15169850
Made a thread about this but probably never going to get a response because clearly I'm too fucking dumb for sci.

How do I force myself to learn math?
I've hated it my entire life. I don't like math and have no desire to learn it. Despite this I'm a STEM major (forced in to it) and just started college. I desperately need to relearn basic algebra or I'm probably going to flunk out in my first semester.

So my question is: how do I stop hating math and learn to enjoy it? I don't know why I hate it but I think it has a lot to do with how arbitrary and random a lot of it seems; all that's focused on is HOW to solve a problem and not WHY that method is used, and that causes major friction for me.

TL;DR: I suck at math and hate it but desperately need it to be the other way around, what do ???

[Anonymous No.15172212]

>>15172184
[math]p: \mathbb{R}^2 \to \mathbb{R}[/math] given by [math]p(x, y) = x[/math] is a continuous map and hence has all of the traditional continuous function properties, i.e. connected domain implies connected image (also known as the stupid version of the intermediate value theorem.)

[Anonymous No.15172218]

the fundamental theorem of arithmetic states that every number can be expressed uniquely as a product of primes. but what if the number in question is prime? I mean, 1 is not a prime so how can a prime number be expressed as a product of primes? if possible, I would like a rigorous explanation

[Anonymous No.15172229]

>>15172187
>How do I force myself to learn math?
You can't, one only learns what he is interested in

>I've hated it my entire life. I don't like math and have no desire to learn it.
Therefore you will not learn it, at best you would memorize it for a week and then forget it.

>Despite this I'm a STEM major (forced in to it)
No one "forced you to it"

>and just started college.
Great time to leave then

>I desperately need to relearn basic algebra
You are not supposed to be in college, univeristies should not accept people who lack the prerequisites

>or I'm probably going to flunk out in my first semester.
I don't care, you're wasting your time, go be a plumber or a doctor

[Anonymous No.15172246]

>>15172212
I only know the theorem that says:
>f: M -> N is a continuous function with (M, dM) and (N, dN) being metric spaces
>If A is compact subset of M, then f(A) is also compact
Unfortunately this theorem is not applicable, since M subset of R^2 is not compact. (Construct a sequence that converges to (0, 0) in R^2; such a sequence does then not converge in M, since there is no (0, 0) in M.)

I'm not sure. How does an connected Im(f) imply that Im(f) is compact?

[Anonymous No.15172275]

>>15172218
good question, primes aren't multiplying anything in their factorication

>>15171337
am i correct to say that the answer is Bob breaks even?

[Anonymous No.15172290]

>>15172275
he lost 8 USD

[Anonymous No.15172324]

>>15172218
The product involves only itself.
>b-b-but you need at least two numbers
Don't be silly, anon. You need no numbers.
https://en.wikipedia.org/wiki/Empty_product

[Anonymous No.15172333]

>>15172218
>the fundamental theorem of arithmetic states that every number can be expressed uniquely as a product of primes. but what if the number in question is prime?
The product involves only the prime itself.

>inb4 a product needs at least two numbers
Ack-chually, a product needs no numbers.
https://en.wikipedia.org/wiki/Empty_product

[Anonymous No.15172349]

>>15172333
that clarifies things. thanks anon

[Anonymous No.15172362]

>>15172349
Welcome. I hope you noticed how it solves the issue of there being no primes you can multiply to get 1: 1 is the unique product of... uh... zero primes. How's that for troll math?

[Anonymous No.15172380]

>>15172290
i just realized it says he sold both for 60 dollars, not that he bought them for 60 dollars

[Anonymous No.15172417]

>>15169850
can someone help me understand what it means by time dependent current?

i dont really understand what i need to do to solve this

[Anonymous No.15172518]

I have three questions

[math]\mathbf{(1)}[/math] For [math]R, A, B, C \in \mathbf{CRing}, f: R \to A[/math], where [math]\mathbf{CRing}[/math] is the category of commutative rings with unit.
Because the tensorproduct functor [math]- \otimes B[/math] is left adjoint to [math]Hom(- , B)[/math] and [math]coker(f) = coeq(f, 0)[/math] is a colimit it is preserved by the tensorproduct functor.
Identifying [math]coker(f) = A / im(f)[/math] is this correct [math]A / im(f) \otimes_C B = coker(f) \otimes_C B \cong coker(f \otimes_C B) \cong (A \otimes_C B) / (im(f \otimes_C id_B))[/math]?

[math]\mathbf{(2)}[/math] Using the fact of the previous tensor-hom adjunction I wanted examples of (co-)limit preservation.
It can be shown that the tensor functor is right exact (with popular examples why it fails to be left exact). But since exact squences (on abelian categories or for simplicity, abelian groups) are defined as [math]im(f_i) = ker(f_(i+1)[/math] but since [math]ker(coker(f_i)) = im(f_i)[/math] I have a mixture of colimit and limit which is not guaranteed to be preserved by the tensor product.
What am I missing and how can I use adjunction to show that hom is left exact resp. tensor is right exact on short exact sequences of abelian groups (categories)?

[math]\mathbf{(3)}[/math] Any idea for basic/easy to understand but still interesting applications of the (co-)limit preserving proberties of adjoint functors as well as the existence properties (Freyd's adjoint functor theorem)?

[Anonymous No.15172537]

Let [math]\mu[/math] be the standard coin tossing measure on [math]X = \{0,1\}^\mathbb{N}[/math]. Let [math]g: X \to X[/math] be an invertible map such that for every [math]x[/math], the sequences [math]x, g(x)[/math] are identical outside of some finite index set (which may depend on [math]x[/math]).

Is [math]g[/math] measure preserving? It suffices to check on cylinder sets, e.g. [math]C = \{x : x(7) = 0\}[/math]. Must [math]\mu(C) = \mu(g^{-1} C)[/math]?

Attempt: Given a finite subset [math]J \subset \mathbb{N}[/math], write [math]S_J[/math] for the set of all [math]x[/math] such that [math]x, g(x)[/math] differ precisely at the indices in [math]J[/math]. Then [math]X[/math] is a countable disjoint union of all the [math]S_J[/math]'s, and one can apply sigma additivity. But now I'm stuck. I'm not sure how to use the invertibility assumption.

[Anonymous No.15172609]

>>15172229
Who hurt you?

[Anonymous No.15172628]

>>15172609
my mother and the bullies at school. Also you need to go back to r*ddit

[Anonymous No.15172823]

>finally made it through the exercises to the next chapter

[Anonymous No.15172858]

>>15172518
In (1) are R and A algebras over C and f is a C-algebra morphism? Why is the tensor product commutative over C?

[Anonymous No.15172868]

>>15172858
>commutative over C
Should be "written over C"

[Anonymous No.15172881]

>>15172187
Why do you want/need to learn math? Look at those reasons, and if you're really motivated then look up what kinds of math relates to solving the problems you want to solve

[Anonymous No.15172921]

>>15172537
What's the coin tossing measure?

[Anonymous No.15172927]

>>15172628
I'm not him but you're a little bitch ass fuckin gay ass bitch

[Anonymous No.15172960]

How do I solve this using logarithms?
Please no bully, I haven't used a logarithm that wasn't natural since 4 years ago.
After NEETIng for a couple of years I need to revisit high school level shit or else I won't be able to follow Calculus I

[Anonymous No.15172981]

>>15172960
The trick they want you to see here is that this is a quadratic equation with the substitution x=3^u
solve the quadratic first and then you can just directly take the logarithm of the solutions

[Anonymous No.15172988]

>>15172981
Oh, so that's why the variable isn't named "x" like in the rest of the problems, I was wondering about that.

[Anonymous No.15173035]

>>15172981
Ok, I have to thank you anon, even if I feel a little bit embarrassed for not seeing the substitution for myself.
I guess I really need to pick up again this way of "reasoning" with exercises. My brain has slept for too long refreshing tabs on other boards.

[Anonymous No.15173067]

>>15172187
When you want to learn anything, your biggest enemy is boredom. Boredom is demoralizing and unpleasant. To learn a new thing I suggest looking for topics you find interesting, or topics you want to make applications of.

Study those and ignore everything else. Then study more as your applications get bigger and more interesting.

For me, I like it when the computer does a lot of math and makes a drawing so I ended up really enjoy Wolfy's books since that's basically 90% of her work. I didn't know Wolfy existed and now I have a paper copy of everything she ever wrote and I have read most of it because I like it when triangles get drawn with a computer.

Other topics where nothing gets drawn or there are a lot of symbols I don't recognize or it is looking at problems I don't understand or don't care about, I find boring if I try to learn them, so usually no effort is made.

If you find something boring, nothing can compel you to engage with it seriously. If you find something fascinating, nothing can compel you to stop engaging with it.

I guess to get started go on a used book site where books are $5-$10 each and buy $100 worth of random math and computer science books that have cool sounding names or have cool looking covers.

I used to go on zlibrary to see if the book has drawings, but zoomers and the USPS burned down z-library and I don't know how to operate the new one.

Also I don't know how working impacts liking a topic. If I was employed like a normal wagie who goes in a cubeicle, to use my computer for boring corporate aims, I think I would like it less because of the loss of agency and the uninteresting application.

[Anonymous No.15173166]

>>15172000
Fry on butter, everything is more yummy fried on butter. Clarified butter is even tastier.

[Anonymous No.15173180]

What's the difference between normality and osmolarity?

If one unit of solute dissociates into i units on average in solution, then wouldn't a 1 M solution of it be both i N and i OsM?

[Anonymous No.15173240]

>>15172218
"Product" doesn't imply at least two primes. Think of "product" in the sense of big-pi rather than multiplication:
[eqn]\prod_{i=1}^n p_i[/eqn]
While products are defined in terms of multiplication, the product of n values involves n-1 multiplications, so n=1 doesn't involve any.

[Anonymous No.15173375]

>>15172609
the truth hurts

[Anonymous No.15173684]

piskunov vs courant vs spivak vs apostol
which is best suitable for an applied mathematics student?

[Anonymous No.15173694]

>>15173684
Read through the first chapter of one of those and see if you can solve every single exercise at the end of the first chapter. If you can, then stick to that one. If not, try another one.
If every single one is too difficult for you, consider learning plumbing.

[Anonymous No.15173958]

>>15172187
Enjoying an action is not a prerequisite to taking an action.
>I don't know why I hate it but I think it has a lot to do with how arbitrary and random a lot of it seems; all that's focused on is HOW to solve a problem and not WHY that method is used, and that causes major friction for me.
Math is the least arbitrary curriculum you can study. It's good that you want to understand why methods work. If you're having trouble understanding a specific topic despite your textbooks, Google searches and YouTube videos, ask your professor or a tutor or here.

[Anonymous No.15174012]

>>15172921
It's the unique measure on [math]X[/math] which satisfies the following: For every pair of disjoint finite sets [math]J_0, J_1 \subset \mathbb{N}[/math], the probability of the set of all sequences [math]x[/math] that are identically 0 when restricted to [math]J_0[/math] and identically 1 when restricted to [math]J_1[/math] is [math]2^{-|J_0| - |J_1|}[/math]. E.g. [math]\mu(C) = 1/2[/math] for the set [math]C[/math] mentioned earlier.

[Anonymous No.15174096]

>>15172187
Every math class is populated with degenerate fucks like you. You all deserve the most painful fucking death possible.

[Anonymous No.15174135]

>>15172187
>all that's focused on is HOW to solve a problem and not WHY that method is used
You are supposed to figure out why it's used.

[Anonymous No.15174140]

>>15172417
It just means you leave [math]t[/math] a free variable.

[Anonymous No.15174143]

>>15172858
for sake of simplicity let them be (R,C)-Bimodules then and everything is a (R,C)-morphism then

[Anonymous No.15174163]

Why is the corollary true only for singular matrices?

[Anonymous No.15174169]

>>15172187
Math feels arbitrary to you since you've probably chosen a major designed by people who know fuck-all about math (specifically math beyond basic algebra). When I took chemistry, never once did we derive one of the formulas we had to use (for some, we even lacked the knowledge necessary to derive it), never once did we attempt to formalize anything of we did (e.g. reaction processes), we were really just memorizing facts and procedures. So glad I switched to math desu.

[Anonymous No.15174178]

>>15174163
0 can't be an eigenvalue of a nonsingular square matrix

[Anonymous No.15174181]

>>15174178
Right, thank you.

[Anonymous No.15174257]

>>15172417
A non-time-dependent current would be like the steady-state response of a DC circuit. You throw a switch that closes a circuit at t=0, then you get a transient (time-dependent) response which settles to a steady state.

Here you have an AC voltage source and a resistor, so you don't have to worry about derivatives or anything that come with reactive circuit elements. You answer will be an equation that models the current through the resistor at point in time t. A(t) = [something] .

(you should be able to solve this)

[Anonymous No.15174271]

>>15169850
Why is editing a LaTeX document such a pain in the ass? How do I edit a LaTeX document like using CSS?

[Anonymous No.15174282]

>>15174271
A well formatted LaTeX document is not that hard to edit. It's when you don't resort to LaTeX principles and resort to de facto hacks that starts making it a pain. Write a proper preamble, organise it into folders, don't use de facto formatting commands outside the preamble, etc. It's better to just stick to the default LaTeX layout if you don't want to learn it properly. You could also try ConTeXt which is a modernised version TeX, but you won't find much packages of that, so you'll have to write a lot of code yourself.

[Anonymous No.15174366]

>>15172537
Yeah, it is. [math]g[/math] being invertible simply means [math]g^{-1}C[/math] is another cylinder set, and then you can use (for example) independence along with induction on the size of [math]J[/math].

[Anonymous No.15174517]

>>15174366
Thanks, but I still don't quite see it... What's bugging me is that for every [math]x[/math] there is a finite index set [math]J_x[/math] on which [math]x[/math] and [math]g(x)[/math] disagree - and this may depend on [math]x,[/math], i.e. [math]g[/math] need not act uniformly on all [math]x[/math]'s. So why must [math]g^{-1} C[/math] be another cylinder set?

[Anonymous No.15174546]

>>15174271
Get a text editor like Sublime and compile the document over the command line

[Anonymous No.15174768]

How do I represent the successor to a natural number such that it cycles back to 1 when it exceeds [math] n [/math]?
[eqn] x - 1 + 1 ( \operatorname{mod} n) + 1 ? [/eqn]

[Anonymous No.15174813]

Question for physicists:
Is there an intuitive explanation why a higher dislocation density leads to a higher non-radiative recombination rate?

[Anonymous No.15174859]

I'm back with another dumb problem a third grader could solve.
I have tried two methods and I was convinced both would give me the correct result, yet both failed me, meaning I must have committed a very dumb mistake, in the next post I'll post my two attempts at solving it.
More than getting to the solution I want to know where along the way of the resolution I fucked up.

[Anonymous No.15174863]

>>15174859
Here are my attempts

[Anonymous No.15174870]

Let [math] T [/math] be a positive, selfadjoint and compact operator on a separable Hilbert space [math] \mathcal{H} [/math]. Let [math] \{e_n\}_{n=1}^\infty [/math] be an orthonormal basis in [math] \mathcal{H} [/math] and [math] \{\lambda_n\}_{n=1}^\infty [/math] the sequence of eigenvalues of [math] T [/math]. Let's denote by [math] M_N [/math] the symmetric [math] N \times N [/math] matrix whose entries are given by [math] \langle e_i, T e_j \rangle [/math], [math] 1 \leq i,j \leq N [/math] and by [math] D_N = \mathrm{diag} [\lambda_1, \ldots, \lambda_N] [/math] the diagonal matrix with the first [math] N [/math] eigenvalues as diagonal entries.

I conjecture that [math] | \det (M_N) - \det (D_N) | \to 0 [/math] as [math] N \to \infty [/math], mainly because I naively think of [math] M_\infty [/math] and [math] D_\infty [/math] as the infinite-dimensional matrix representations of the operator [math] T [/math] in two different bases and the determinant of (finite-dimensional) matrices is invariant under a change of basis.

So far I wasn't able to prove this statement, so I wanted to ask whether it is actually true and if so whether you could give me some hints on how to prove it. Thank you very much frens.

[Anonymous No.15174883]

>>15174768
x mod n + 1

In programming, more common* is, however:
(x+1) mod n
which cycles it back to 0.

*Unless you're using Lua or something that starts the array from 1.

[Anonymous No.15174981]

>>15174768
x-1 (mod n-1) + 1

[Anonymous No.15174987]

>>15174981
>successor
whoops, change the x-1 to just x

[Anonymous No.15174995]

>>15174981
>>15174987
Thanks.

[Anonymous No.15175009]

>>15174859
>>15174863
second method looks right. why did you stop?
also, you wrote 800 instead of 801 in the last line.

[Anonymous No.15175017]

>>15175009
>why did you stop?
... because I wrote 800 instead of 801 and the result on the calculator wasn't making sense....

[Anonymous No.15175021]

>>15175017
ah, happens. the solutions are 9 and 89 btw.

[Anonymous No.15175069]

>>15174257
thanks, this helped a lot. I feel like a fool for letting it confuse me this much

ive got one more problem i got stuck on. I dont want anyone solving it but im confused as to what equations i should be using that uses all of these givens

[Anonymous No.15175078]

How does friction even work? I placed a beer glass on it's side on my laminated desk and spun it like a rolling pin. Initially it stands still while spinning, defying all reason, only after the initial energy wears off, and it spins slower, it starts to move in the direction it was spun.

[Anonymous No.15175082]

Is this chart a meme? I really want to learn some calc to help with my programing skills since i was too broke to go to collage. How long would it take to complete it? Are there any better alternatives?

[Anonymous No.15175083]

>>15175069
you use the definition of a capacitor, [math]I_c(t) = C \frac{d}{dt} V_c(t)[/math].

[Anonymous No.15175106]

>>15175082
>I really want to learn some calc to help with my programing skills
just read a calculus book. can i ask why you want to learn calculus? linear algebra is usually far more useful for programmers.

[Anonymous No.15175107]

>>15175083
this is what i ended up with.

[Anonymous No.15175112]

>>15175107
looks plausible but i dont have a pen and pad in front of me

[Anonymous No.15175116]

>>15175082
>Is this chart a meme?
It's bloated, if anything. I have read almost none of those books but you don't need 7 before you start calc.

[Anonymous No.15175127]

>>15175107
wait i take it back this isnt plausible at all. you shouldnt have t in your equation, and you shouldnt have arcsin either, especially not arcsin(-5000). can you show your work please?

[Anonymous No.15175129]

>>15174870
>So far I wasn't able to prove this statement
That's because it's not true.

[Anonymous No.15175143]

>>15175127
i have shit hand writing so im sorry

[Anonymous No.15175152]

>>15175143
i forgot the part where i took the derivative of v(t) but i might have done that part wrong

[Anonymous No.15175154]

>>15175143
the current thought the cap isnt 100mA, its a sinusoid. you can see this from the equation i posted, but also you should just know that if you put a sinusoid voltage over a cap then the current will be another sinusoid thats 90 degrees out of phase.
find the current through the cap with the givens you have and the equation i posted, then find the frequency such that the maximum current is no more than 100mA.

[Anonymous No.15175158]

>>15175129
Thanks, but could you elaborate a bit more? Maybe a counter example?

[Anonymous No.15175159]

>>15175152
yes i believe you did do that part wrong. remember youre deriving with respect to t, but the inside of cos is a bunch of other stuff, so you have to use chain rule.

[Anonymous No.15175167]

Let’s assume you have the reciprocal of ‘x + 1’. When you use u-substitution to find the integral, can we write the integral in terms of dx instead of du since dx = du, or does that violate the rules of integration?

[Anonymous No.15175171]

>>15175167
i guess you can, but [math]\int \frac{1}{u} dx [/math] doesnt really make sense. if du = dx then theres really no point in doing a u sub.

[Anonymous No.15175173]

>>15175106
because i don't want to dive straight into the deep end. I know linear algebra is more important but i heard its way more advanced so i just assumed i needed know the "foundations" of math before i tackle it. Plus it wouldn't hurt to learn some additional math to help improve my problem solving skills
>>15175116
What exactly do you need to know to take on calc? What would you take out?

[Anonymous No.15175183]

>>15175173
listen to us. calculus is taught to high schoolers. analysis and set theory is undergraduate math. just read a calculus textbook, i promise you will have no trouble following along. you do not need to learn analysis before calculus.
linear algebra is also undergraduate math but its pretty self contained so you probably wouldnt have much trouble reading that either.

[Anonymous No.15175190]

>>15175173
also, i recommend Stewart calculus. its a very long text meant for high school. itll take you all the way from limits to vector calculus.

[Anonymous No.15175199]

>>15175154
im still super confused but ill stop bothering you. thank you for your help thus far

[Anonymous No.15175210]

>>15175199
okay, one step at a time. take the derivative of the voltage with respect to time.

[Anonymous No.15175212]

>>15175210
-20*pi*f sin(2 pi f T)

[Anonymous No.15175215]

>>15175212
alright, now multiply that by the capacitance as per the equation in >>15175083 to get the current through the capacitor (notice how it is a function of time, not a constant).

[Anonymous No.15175225]

>>15175215
okay so now i have i(t)

-pi*f*sin(2pi f t) / 25000

[Anonymous No.15175232]

>>15175225
good. now the problem says that the supply can only deliver 100mA (and we know that the current through the supply is the same as the current through the cap since theres only the cap connected to the supply). knowing that sin(x) can only ever have a maximum value of plus or minus one, how do we find f such that the sin wave will never go above 0.1?

[Anonymous No.15175236]

>>15175232
i dont know

[Anonymous No.15175243]

>>15175236
you know how sin(x) is a wave that fluctuates between +1 and -1? and 0.5sin(x) is a wave with the same frequency that fluctuates between +0.5 and -0.5? we want our wave to fluctuate between +0.1 and -0.1

[Anonymous No.15175280]

>>15175183
>>15175190
thanks for the advice anon. I'll take your advice and go straight go straight for calculus. and one more question when choosing text books. Does the edition number matter at all? or is it just some publisher scam? There are multiple version of james steward's calculus on libgen

[Anonymous No.15175287]

>>15175243
multiply by .1?

[Anonymous No.15175288]

How good is khan academy? I see a lot of calculus which is good but not a lot of physics.
Is it a good substitute of a textbook for calculus or should I still dip my toes in a book the professor might recommend?

[Anonymous No.15175295]

>>15175288
better off using professor leonhard + organic chem tutor

[Anonymous No.15175296]

>>15175280
iunno, i’d just go with the most recent edition
>>15175287
all of the stuff thats being multiplied by the sin term is called the amplitude. we want the amplitude to be 0.1

[Anonymous No.15175298]

>>15175295
I will consider it, but regardless of what is the best possible option, is khan at least good?

[Anonymous No.15175300]

>>15175298
he's okay and will get you by but the other options i mentioned are way better for what you're asking

[Anonymous No.15175303]

>>15174863
"Cancelling" [math] \log[/math] like a fraction is cringe notation. Either raise both sides by 10, or use the fact that [math] \log[/math] is one to one.

[Anonymous No.15175313]

>>15175296
set the equation equal to .1

[Anonymous No.15175341]

>>15175300
Holy shit this leonhard guy is chad as fuck, I will watch him

[Anonymous No.15175345]

>>15175341
well he is called "calc chad" for a reason

[Anonymous No.15175346]

>>15175300
>>15175341
Just a question on the level of his courses, I'm studying engineering, but I'm fine with math degree level classes. Is this guy teaching calculus at it's full extent or just the calculus they will ask for me in engineering?

[Anonymous No.15175350]

>>15175346
caclulus at its full extent but most of it is used in your engineering courses

[Anonymous No.15175352]

>>15175303
there is nothing wrong with it desu

[Anonymous No.15175358]

>>15175350
Oh, I thought mathematicians did more.
Does he also do videos on higher level mathematics? (purely interested, obviously sticking to what I need for now)

[Anonymous No.15175365]

>>15175358
they do do more, but prof leonard only covers undergrad topics from algebra to diff eq which i guess is mostly the engineering math. If you're looking for proof based stuff you have to look elsewhere

[Anonymous No.15175371]

>>15175313
set the amplitude to 0.1

[Anonymous No.15175419]

>>15175303
cringe

[Anonymous No.15175427]

>>15169850
Is there a way to make a big latex document compile faster? I am trying to typeset hundreds of bmatrixes on thousands of pages and my compile time is like 15 minutes.

I haven't even added the margin maids yet.

I don't want to have to wait 15 minutes to make sure every single image is in place.

How can I make latex go faster?

[Anonymous No.15175440]

>>15175427
-j8

[Anonymous No.15175470]

>>15175440
I don't know what this means.

[Anonymous No.15175610]

>>15175470
it’s the “jobs” flag. C compilers will run n processes simultaneously if you pass -jn during compilation, to take advantage of multi-core cpus. probably doesnt work with whatever latex compiler youre using.

[Anonymous No.15175693]

>>15175610
I am using TexWorks which I think is using pdftex. My Latex knowledge is not very advanced because I never thought what if I need to use this to make a math book?

I made a small helper program called Senko MaidHelper that can count a Maid Space and generate Latex code for it. That way I don't have to write bmatrix a lot of times by hand.

So I have a section where I count from 0 to whatever the Maid Space's Capacity is in a 2 by 2 Maid Space. I used MaidHelper to generate the code that draws the Maid Spaces.

When it compiles, the resulting PDF is less than 1 MB so I am not sure why it is taking so long. It just needs to draw squares a lot of times.

When it finishes compiling I will post a page that has the Maid Spaces getting counted.

Maybe if it is too big I can make it a separate book? Then it can be a series of books and have more things to print and give to other scientists if I get to go in a science meeting?

[Anonymous No.15175716]

>>15174863
Second method is correct until the last line. The roots are 49±40 = {9,89}.
x=9 => x+1=10,x-8=1 => log(x+1)=1,log(x-8)=0 => 2log(x+1)-log(x-8) = 2-0 = 2
x=89 => x+1=90,x-8=81 => log(x+1)=1+log(9),log(x-8)=2log(9) => 2log(x+1)-log(x-8) = 2+2log(9)-2log(9) = 2.

[Anonymous No.15176005]

>>15175693
Why not split the document into separate chapters, and recompile only the parts that you modify?
https://www.overleaf.com/learn/latex/Management_in_a_large_project

[Anonymous No.15176020]

why does salt water being inoculated with mold cultures make it more viscous after letting it hydrate for 2 days?

[Anonymous No.15176134]

>>15176005
Thank you for telling me. I will try this. I compiled the document and my drawings added 280 pages so probably they need to just go in a separate document because chapter 4 doesn't need to be 300 pages long.

I tried to copy the pdf from the Writing Computer to the Science Computer but my thumb drive is giving me problems and I will be unconscious in 15 minutes, so I will try again tomorrow.

[Anonymous No.15176198]

>>15171779
>I'm an EE undergrad
>I don't really like electronics
Then why the hell did you pick EE as your major?

[Anonymous No.15176485]

Give me hints on how to solve this problem. I ran out it ideas to apply.

[Anonymous No.15176494]

how can I give sentience to an anime girl?

[Anonymous No.15176656]

Hi there, I am doing an assignment for "Social studies" about "Fake news, algorithms" and all that. It is supposed to be used in our practice to showcase in front of a bunch of pupils.

I am wondering, are there any relatively simple and easy Deepfake programs out there? It would really showcase for my pupils that you can't trust anything you see or hear if I made a video showcasing myself as another person.

[Anonymous No.15176670]

If you haven't received an interview from a grad school at this point does that mean you are not getting into that school?

[Jealous No.15176687]

>>15176485
Quadrature.

[Anonymous No.15176805]

>>15176494
Actual women lack sentience, so your anime girl lacking it just makes her more lifelike. Consider the lack of sentience to be a feature rather than a bug and declare the problem solved.

[Anonymous No.15176840]

>>15176198
I got into it 7 years ago while I was still a dumb kid that didn't know what he wanted to do. I really hated it, so I dropped it. Resumed my studies last year so I don't end up a hobo. I don't really hate it anymore, it's fascinating at times even, but having to study something this complex while having no innate interest in it just makes me want to distance myself from it, at least professionally. Still, it's a great principle to study and allows me to jump into virtually anything related to tech, thus my question.

[Anonymous No.15177090]

True or false: algebraic multiplicity of an eigenvalue is the maximum cardinality of the set containing pairwise independent eigenvectors corresponding to it.

[Anonymous No.15177108]

>>15177090
False.
Consider the matrix
1 1
0 1
It has a double multiplicity eigenvalue 1, but the maximum cardinality of the set containing pairwise independent eigenvectors corresponding to it is 1

[Anonymous No.15177126]

>>15177108
Okay, thank you. But is there any relationship between algebraic multiplicity and geometric representation of linear transformations?

[Anonymous No.15177208]

>>15176485
How about you make it legible first

[Anonymous No.15177229]

>>15175371
explain

[Anonymous No.15177235]

>>15177208
Here anon...

[Anonymous No.15177381]

Any medicine practicioner willing to do free prostate exam on me?

[Anonymous No.15177508]

Is there more than one way to embed (just algebraically, not continuously) the algebraic closure of the rationals, into the complex numbers?

I forgot how Galois theory works lmao

[Anonymous No.15177511]

>>15177235
Multiply by the denominator's conjugate you numbskull

[Anonymous No.15177555]

>>15177235
Multiply the top and bottom by the conjugate of the denominator (meaning replace +cos by -cos)

[Anonymous No.15177680]

can anyone guide me in solving this diff eq?

it would help me a lot to see a worked example

[Anonymous No.15177833]

>>15169850
Could the formula for the sum of a square series (1 + 4 + 9 + 16 +.....) be obtained just using pic related?

[Anonymous No.15177835]

I know pic related is a fuel transfer unit. Filters, gear pump, non-return valve. What I can't find any info on is what sort of standard this is so I can look up info on the rest of the symbols. Google only gives me P&ID which is an entirely different standard with completely different symbols.

[Anonymous No.15177836]

>>15177680
t dw/dt + 2w = 0
=> t dw/dt = -2w
=> -1/(2w) dw = 1/t dt
=> -(ln w)/2 = ln t + c1
=> ln w = c2 - 2 ln t
=> w = c3 / t^2

[Anonymous No.15177838]

>>15177836
thanks, looks like i was just overthinking a step

[Anonymous No.15177862]

>>15177235
>>15177555
What do you intend to do then?
(I didn't post the q but don't think it's solvable)

[Anonymous No.15177871]

>>15177833
No clue what your picture is doing but there's this

[Anonymous No.15177899]

>>15177871
Pic related is adding series of dots stacked into triangles.
An alternating pattern emerges adding them.
1 = 1^2
1 + (1+2) = 2^2
1 + (1+2) + (1+2+3) = 1^2 +3^2
1 +(1+2) +(1+2+3) + (1+2+3+4) = 2^2 + 4^2

If you added (1+2+3+4+5), it would become 1 + 3^2 +5^2 , and so on.

I know of your picture, though I'm wondering if that same series could be obtained using just this, or if it has its own implications.

[Anonymous No.15177922]

>>15177229
bro come the fuck on

[Anonymous No.15177974]

Can someone help a complete math brainlet with this?

For each user that accesses a given application, a random PIN with 4 different digits is generated.

Given 2 randomly and independently generated PINs, what is the probability that these two have two digits in common?

[Anonymous No.15178011]

>>15177862
Just do what I said, multiply by 1+cos . It should be doable after that.

[Anonymous No.15178012]

>>15177974
Without loss of generality assume that one of the PINs is 0000. Then it becomes obvious that the number of equal digits of the second PIN is binomial distributed.

[Anonymous No.15178014]

>>15178011
Sorry multiply by 1-cos , since the denominator is 1+cos .

[Anonymous No.15178023]

>>15178012
The PIN is made of 4 different digits, 0000 wouldn't be a valid one.

[Anonymous No.15178041]

>>15177922
how do i set it to .1?
he didnt said i was wrong when i said to multiply it by .1

yes im retarded.

[Anonymous No.15178043]

>>15178041
sorry
he did say*

[Anonymous No.15178093]

>>15178041
draw an equal sign.
on the left side of the equal sign, write down the expression for the amplitude that you found.
on the right side of the equal sign, write 0.1.
i know you didnt take that derivative yourself. you used wolfram. theres no way you can take a derivative but not set something equal to 0.1. im losing my fucking mind over here.

[Anonymous No.15178115]

>>15178023
Okay, if the PIN is made for 4 different digits, then the problem is actually much simpler. If you can replace the digits like a real PIN can (you can have 1111 as a pin, for example), the problem because more annoying to solve.

[Anonymous No.15178134]

>>15178012
>Without loss of generality assume that one of the PINs is 0000.
bruh

[Anonymous No.15178147]

>>15178093
sorry to say i did take the derivative myself but i admit i used the derivative calculator to check just in case

[Anonymous No.15178371]

>>15178011
Should I multiply the y to 2y? That's where I got stuck to this problem.

[Anonymous No.15178379]

>>15177508
Yes. Ignoring literally everything for one second, we can do so because the complex numbers have a non-trivial automorphism (conjugation.)

[Anonymous No.15178426]

>>15178115
You can't have repeated digits

[Anonymous No.15178581]

Is there a trick to carrying out arithmetic operations using large rationals without a calculator? I’m going to be taking an exam involving numerical methods and my professor won’t allow calculators.

[Anonymous No.15178647]

Someone can show me a trick for solving this one? I want to learn a fast and easiest way to solve this kind of integrals. I'll be thankfull alot.

[Anonymous No.15178682]

>>15178647
look up hypertrigonometric functions

[Anonymous No.15178700]

>>15178682
Thanks. But my head's dumb right now to understand what sinh x is, as it's equivalent to (ex – e–x)/2.

[Anonymous No.15178720]

>>15178647
I think you're going to need to just use the binomial expansion. Although it's simplified slightly by symmetry and e^x.e^-x=1, so you only get even-degree terms.

[Anonymous No.15178738]

>>15178720
>binomial expansion
Ohhhh, thanks anon :)

[Anonymous No.15178784]

>>15178371
Use this anon. First use the conjugate as the other bro said. Then you can replace using the second identity to 1-(1-2sin^2y). Simplify and then use in the denominator the trigonometric identity 1-cos^2y=sin^2y. Simplify both sin^2y and take out of the integral the 2. Then you can calculate the integral of 1-cosy being equivalent to -siny and as you had the 2 out, you put it as -2siny.

[Anonymous No.15178797]

>>15178784
I forgot another thing. The integral of 2-cosy has the integral of 1dy too, that is equivalent to 2y. As it's an antiderivate, you put +C at the end. And that' it.

[Anonymous No.15178931]

>>15178797
I am getting it know let me try solving it.

[Anonymous No.15178938]

>>15171779
Sell fried chicken

[Anonymous No.15179052]

What is the probability of getting an even number when rolling an infinite sided dice? Why isn't it 1?

[Anonymous No.15179072]

i'm looking to go to college for a compsci degree. i'm already very familiar with majority of prog langs (c++11, c17, haskell, etc) yet i have 0 experience with math as i dropped out of high school around 4 years ago. what math courses should i take on khanacademy before i attempt to get my ged, looking to score high enough to go to my state's college.

[Anonymous No.15179188]

Does f(x,y) = x + iy count as a bijective function?

[Anonymous No.15179190]

>>15177974
At least two digits, or exactly two digits?

[Anonymous No.15179252]

>>15179188
Yes

[Anonymous No.15179255]

>>15179052
Why would it be 1? What would be the probability of getting a not even number? They have to add up to one, so it would have to be 0, but why would that be less likely?

[Anonymous No.15179263]

>>15169850
https://en.wikipedia.org/wiki/Electroejaculation

anyone know how I can do this to myself? people usually do it while under anesthesia and are unconcsious, but I'm wondering if that has more to do with the dignity of having something up your ass than actually preventing pain.
could I buy a tens unit or something and do this procedure myself?

asking for a friend

[Anonymous No.15179369]

>>15179190
Exactly two

[Anonymous No.15179374]

>>15178426
Just imagine that the pin is a certain number like 0123, and then count the number of combinations that exist that it the requirements. For example for all 4 numbers being the same, there is
0123, 0132, 0213, 0231, 0321, 0312
1023, 1032, 1230, 1203, 1302, 1320
Etc. you’ll see there are 24 combinations. Every one of these combinations has the same chance of occurring, and the chance of getting any of them is simply the sum of them. The total number of possible combinations is less than 10000. Just use this method to find the pattern.

[Anonymous No.15179376]

Should I claim that I'm transgender on my college application?

[Anonymous No.15179383]

>>15179376
Yes. There is literally nothing they can do to stop you. They will make no effort to challenge your asserted identity even if you look like gigachad and don't even pretend to try to transition in any meaningful way.

They are too scared to point out that the emperor has no clothes (and also a penis) because it directly contradicts their ideology about gender identity.

According to them, you're a woman if you say you're a woman and nothing else, least of all observable physical reality matters. Make them play by their own rules. Abuse the system for acceptance/scholarship money/awards. You're diverse now! You can be mediocre at anything and have a built in audience of people who think you're a stunning and brave heroine.

Be sure to apply for a lot of women's scholarships and screech about transphobia if you don't get them too.

[Anonymous No.15179520]

is the salt in human's tears iodized or non-iodized

[Anonymous No.15179527]

>>15176005
I was able to use this strategy. Here is a random slice of two by two counting in radix nine. I need 4444 big titty anime maids to finish my books.

[Anonymous No.15179707]

Is there any way to access zlibrary without using tor?

[Anonymous No.15179763]

[math]
\displaystyle
\int x^x\ dx
[/math]

What is it?

[Anonymous No.15179786]

>>15179763
Wolframalpha says no result found in terms of standard mathematical functions, so that settles it

[Anonymous No.15179789]

>>15179763
next time ask google

https://math.stackexchange.com/questions/141347/finding-int-xxdx

[Anonymous No.15179790]

>>15179763
>>15179786
It does have a closed form but it's very complex.
https://math.stackexchange.com/questions/141347/finding-int-xxdx

[Anonymous No.15179793]

>>15179790
>closed form
>infinite sum
You don't understand what "closed form" means, do you?

[Anonymous No.15179798]

>>15179789
>>15179790
I see no closed-form answers there. They're just doing power series or other sequences converging to it.

[Anonymous No.15179800]

>>15179789
>>15179790
Why is there a meme going around that it's impossible to integrate (even though it clearly is possible)?

[Anonymous No.15179802]

>>15179793
Yeah I got my terms mixed up

[Anonymous No.15179803]

Is it possible to conduct a study and get it peer-reviewed and considered scholarly if you have no post-graduate degree, credentials, and do not work for any institution? Forget about how realistic it would be, I'm just asking about possible period.

[Anonymous No.15179804]

>>15179800
because people think "no way to represent it in elementary functions" means it can't be done

[Anonymous No.15179811]

>>15179800
>>15179804
Literally any measurable function can be integrated dumbass, the point is to see if we can algebraically solve it in closed form using known functions

[Anonymous No.15179821]

>>15179811
Why are you acting like I'm not aware of this

[Anonymous No.15179826]

Artificial selection is really cool, is there a way to domesticate bacteria?

[Anonymous No.15179833]

>>15179821
I was responding mainly to >>15179800 which asked
>Why is there a meme going around that it's impossible to integrate
The reason is that it's impossible to integrate it algebraically, in closed form, in terms of known functions.

[Anonymous No.15179835]

>>15179811
What is the significance of finding a closed form in known functions?

[Anonymous No.15179850]

>>15179835
It looks nicer and it's significantly easier to calculate.
That's about it.

[Anonymous No.15179861]

>>15179850
Let me rephrase the question. In what context is the integral of x^x useful?

[Anonymous No.15179868]

>>15179835
Nothing of immediate use, but it's good to know so we can keep records and tables.

[Anonymous No.15179875]

>>15179861
It is the solution of the differential equation dy/dx = x^x

[Anonymous No.15179878]

>>15179861
That's not rephrasing the question, that's a completely different question.

[Anonymous No.15179892]

>>15179878
It still means the same thing, even if it's a different question.

[Anonymous No.15179918]

>>15169850
Good Morning /Sci/entists!

I have been drawing squares with colors in latex. I am using the colors that come with xcolor. Is it possible to make custom colors? I want to use the same color palette as an NES so I can demonstrate counting to NES sprites in a Maid Space.

Thank you /sci/entists for reading my post.

[Anonymous No.15180031]

How do you guys self-study math? Do you write down all the theorems, examples, try to do all the exercises, etc.?

[Anonymous No.15180114]

[math]\displaystyle \int \frac{dx}{(1 + x^2)^2}[/math]

Can you integrate this with partial fraction decomposition?

[Anonymous No.15180126]

>>15169850
What the fuck do the vertical lines around a vector (like: |v|) mean?

[Anonymous No.15180132]

>>15180114
At least at first glance it looks like there should be no issues. What is your decomposition?

>>15180126
|v| is length of the vector v

[Anonymous No.15180135]

>>15180031
Think of which problems and theorems interest you and work backwards from them; keep them in mind as motivation.

[Anonymous No.15180136]

>>15180126
I think that's just the norm of the vector.
https://mathworld.wolfram.com/VectorNorm.html

https://en.wikipedia.org/wiki/Norm_(mathematics)
For the length of a vector in Euclidean space (which is an example of a norm, as explained below), the notation |x| with single vertical lines is also widespread.

[Anonymous No.15180141]

>>15180114
>>15180132
Actually wait, if you do the PF decomposition on this (without splitting 1+x^2 into complex roots) then you get a term like (Ax+B) / (1+x^2)^2 , so that doesn't really make things easier.

My guess is something might be possible with complex splitting

[Anonymous No.15180145]

>>15180114
doesn't work, you have to something with arctan

[Anonymous No.15180150]

>>15180141
>so that doesn't really make things easier.
Actually I'm a moron; not only does it not make things easier but you should get back what you started with. Since the denominator we started with was already a power of an irreducible polynomial (again, unless you take a complex splitting).

[Anonymous No.15180281]

>>15180114
https://www.youtube.com/watch?v=DmdWIWSH904

[Anonymous No.15180434]

>>15179918
If you put something like

\definecolor{MaidPink}{RGB}{255,135,152}

in your preamble then you can use it in the text like

{\color{MaidPink} some text }

[Anonymous No.15180446]

>>>/wsr/1314714
I want to bring attention to this thread because I saw the image that OP is describing on /sci/, but I didn't save it. Does anyone have it?
>>>/wsr/1314714

[Anonymous No.15180451]

WTF is the difference between powdered and microgranular cellulose?

[Anonymous No.15180484]

in this equation if i was given p(t) and L, and i had to find I(t), would i just integrate both sides?

[Anonymous No.15180519]

At what point does math require serious brainpower? Real-analysis I'm guessing?

[Anonymous No.15180523]

>>15180519
Maybe. Depends on the brain unfortunately. For a lot of people the symbols will dance in front of their eyes when they have to solve a quadratic equation.

[Anonymous No.15180536]

>>15180434
Thank you for telling me. I will experiment more with this. I think I can use Maid Space to draw all the possible colors.

I have another problem. I made another book with black-and-white only Maid Space. They were 1 by 1, 2 by 2, 3 by 3 and 4 by 4. Then I made another where they were 1 by 1, 4 by 1, 9 by 1 and 16 by 1. Then I tried another one that is 1 by 1, 1 by 4, 1 by 9 and 1 by 16.

I noticed it won't compile if my bmatrix has a row longer than 10. How can I defeat this restriction?

[Anonymous No.15180550]

>>15180536
http://www.ams.org/arc/tex/amsmath/amsldoc.pdf
the section on matrices says that

\setcounter{MaxMatrixCols}{15}

in the preamble should work.

[Anonymous No.15180552]

Probability bros.

I am doing my last assignment and I am struggling to find a formula for a twist on the "birthday paradox"

"If 5 persons are in a room, what is the chance that everyone has a different birthday date?"

(We assume the year has 365 days)
(We assume every day has the same probability)
(We assume all the birthdays are independent of each other)

[Anonymous No.15180562]

>>15180552
p(everyone has a different birthday) = 1 - p(a birthday overlaps), and this latter probability you should know from the birthday 'paradox'.

Although afaik this latter probability is usually calculated by taking the complement again and just calculating the probability of no matching overlaps, so to me your question is independent of the birthday paradox.

[Anonymous No.15180572]

>>15180562
English isn't my first language, so I am struggling a bit.

We haven't had anything about the birthday paradox yet, it's just that it mentions it in the assignment.

The first task asks; "How many different possibilities are there in total for the birthdays in this 5-person group?"

Sorry if I am retarded

[Anonymous No.15180589]

>>15180572
Oh okay.
Do you know stuff about arrangements, permutations and combinations? (you should)

[Anonymous No.15180600]

>>15180589
Yes, I think so if you're referring to arrangements as ordered/not ordered.

[Anonymous No.15180640]

>>15180552
>>15180600
Okay, so there are 365 possible spots to put 5 birthdays in. If they cannot overlap then in how many ways is this possible?

[Anonymous No.15180649]

>>15180640
360? 365-5, right?

[Anonymous No.15180659]

>>15180649
Surely, if there are two people, there would be 365 options for person 1, and then 364 options for person 2 (they cannot overlap and person 1 already has filled a day), so 365*364 options for both, no?

Try again

[Anonymous No.15180671]

>>15180649
(365 choose 5) = 365!/5!/360!.

Let's say you order the days arbitrarily and you identify the first 5 spots in your order with the 5 people you are considering.
There are 365! ways to order the days, but then you are overcounting by all the ways you have ordered the 360 'useless' spots after the first 5.
These will not affect the identified birthdays for the first 5 people so you have to correct for them by dividing by their number of orderings again (=360!).
Also the ordering of the five people is arbitrary, so you have to divide by 5! also.

[Anonymous No.15180677]

>>15180671
So you just scale 5! with (whatever number of people) i.e. for 10 it's 10! and removal of a similar amount of days from 365? If I understand that correctly?

So It's 365!/X!/365-X!, so to speak?

[Anonymous No.15180684]

>>15180677
yes, in general. But imo it's a bad idea to learn formulas like that because you will mess up when the question changes slightly.

But if you have to 'choose' k distinct items from some collection of n items then you can do so uniquely in (n choose k) = n!/(k!(n-k)! ways.

here you have 365 days and are choosing 5 distinct days for the 5 people.

[Anonymous No.15180692]

>>15180684
I think I am getting a grasp of it now.

Pic related is the tasks for the assignment, but I calculated 365!/5!/360! and it gave me like 52 billion possibilities, are there really that many possibilities? or did I fuck up?

[Anonymous No.15180732]

>>15180692
Yes, although in this case the people are named (so distinct), so it is even higher as you wouldn't be overcounting the ordering of the 5 people. (so 365!/360!=6302555018760).
Large numbers are not uncommon (you will be dividing eventually by an even larger number to get a probability in [0,1])

[Anonymous No.15180738]

>>15180732
Hmm, think I get it non. Thanks, anon

[Anonymous No.15180761]

>>15178093
>>15175243

just want to say i got confused as fuck because i didnt know/understand that we completely ignore the sin function due to the -1 to 1 property. This has never come up in my math courses as a problem. so this must be some physics thing or it was some minor rule in my math text book that I glossed over and forgot.

it seems i have arrived at the "correct" answer my last dumb ass question is if i keep the negative sign in my final answer or should my answer for frequency always be positive

[Anonymous No.15181233]

when does calculus Ii become fun

[Anonymous No.15181319]

>>15181233
Trick question. You either
a) enjoy it right from the start
or
b) start enjoying it as soon as you see applications of Calculus in various fields of your interest (be they Physics, engineering, chemistry, biology, economics, or statistics)
c) feel glad you understood Calculus II material at all once you come across even longer and more difficult problems to solve in Calculus III
or
d) never enjoy it at all
or
e) start enjoying it after you practice solving so many problems and go through so many proof-writing exercises that you become numb to the feeling of boredom

[Anonymous No.15181326]

>>15181233
as soon as you set up an integral for yourself in some applied field like physics
>>15180761
> i didnt know/understand that we completely ignore the sin function due to the -1 to 1 property.
zero excuse, brother. i was spoon feeding you. i even explicitly said that the sin part was unimportant.
>should my answer for frequency always be positive
frequency should always be positive. negating the amplitude of a sinusoid has the effect of flipping it over, which doesnt matter for this problem but it might for others.

[Anonymous No.15181342]

>>15181326
You are very patient with retard anon, that is always nice to see here.

[Anonymous No.15181348]

>>15181233
when you ignore the shitty bits and start applying it to fun stuff

[Anonymous No.15181416]

>>15180640
>365
Leaplingbros…

[Anonymous No.15181552]

Probably a dumb question but when we row-reduce a matrix, can we perform multiple row operations for each step?

[Anonymous No.15181605]

>>15181552
Row-reduction is equivalent to pre-multiplying by a matrix. Ax=b => MAx=Mb. You can do what you want as long as you apply the same operation to both sides. But note that if you're reducing a matrix to triangular form to calculate the determinant, you're limited to pre-multiplying by a matrix with unit determinant, e.g. a matrix which is essentially the identity matrix except with a single non-zero off-diagonal element (corresponding to an elementary row operation).

[Anonymous No.15181631]

If A,B are two finite sets of the same size, is it true that the set differences A\B and B\A also have the same size? And if so, why?

[Anonymous No.15181632]

>>15181631
[eqn]|A\setminus B| = |A| - |A \cap B| = |B| - |A \cap B| = |B \setminus A|[/eqn]

[Anonymous No.15181658]

>>15181632
Thanks anon. I tried to construct a bijection and failed, I realize now it's because I didn't use the finiteness assumption.

[Anonymous No.15181731]

>>15180550
Thank you for telling me. This worked and now I have over nine thousand pages of math research to publish.

I am going to use the example you made with the color to make all the colors get counted.

I was going to put maids in all my margins but that seems futile now because I don't know where to get 50k+ big titty anime maids. The scale of the thing is getting too big so maybe I reduce the margins to normal sizes and recompile everything and the start of each section and each front and back cover gets a maid?

Also printing some of this can be a problem. Wolfy's triangle book weighs 50lbs and is 6 inches thick. The second volume of on-off is 3600+ pages long so probably it wouldn't be nice in a paper form.

[Anonymous No.15181879]

>>15181326
You're right no excuse.


>frequency should always be positive. negating the amplitude of a sinusoid has the effect of flipping it over, which doesnt matter for this problem but it might for others.

Figured just wanted to make sure.


As the other anon said,I appreciate your patience.

[Anonymous No.15181887]

>>15181731
I might have a new problem. I wrote the code that generates a definecolor for all the possible colors you can make. It makes a 1 by 3, radix 256 Maid Space and coints from zero to 256^(3)There are 256^(3) colors now and just the declarations for colors made 621.57MB of text.

I am going to see how many 1 by 1 Maid Spaces I can typeset on the same line and then see can I draw a Maid Space for every single one of them?

This might just cause texworks to crash. It doesn't like it when I tell it to compile a half million lines and this is going to be orders of magnitude more lines.

This might exceed practical limits of the Science Computer.

>tl:dr; I might need a more powerful computer to do this.

[Anonymous No.15181889]

>>15181887
lmao what are you doing? It looks like you have re-invented _an image_ with 16M colours, but rendered entirely in colored pixels in latex' bmatrices.

[Anonymous No.15181905]

>>15181879
Okay now this is seriously bothering me now. I've been trying to look for resources on the internet to learn more about this rule ( where you ignore sin due to -1 to 1) but I can't find anything.

[Anonymous No.15181946]

>>15181889
I was working on the Maid Phone but I kept having problems so I started making a book so I can get ideas arranged properly and refer to previous ideas because a lot of times I forget I already made the idea.

I was reading my book and I thought wow this book sucks. Why is my own book boring me? It doesn't have any colors. It doesn't have very many pictures. The best science books all got written by Wolfy because she uses a high amount of images and symbols and a low amount of words. So I write a Computer Program that counts in MaidSpace with any radix for the cells and output to latex so I can compile the output in latex and use pdf drawn by latex as a display layer for my experiments. That way I can draw an experiment my book and it will get nicer like the triangle book is.

This caused Chapter 4 to become more than 300 pages long so I decided make it into it's own book. Then I got more experiment ideas from looking at pages and spent all day doing it and now I have over nine thousand pages of math research typeset in six books. The first three books are all north of 300 pages. The fourth is just north of 2k pages. The fifth and sixth both exceed 3000 pages. I was going to put anime maids in all the margins but then I realized I need about 50k of them already and I am not done using my computer because I have to have 12 books and release them all in CC0 so that when I go in a science meeting, an assistant can bring a lot of copies of my books and I can give away books to the other scientists and they can see how counting works more and I get a copy of their research and see how their idea works too.

2023 is the year of the dra/g/on so I have to become earth's most prolific Computer Scientist. I have to print more pages than Wolfy has. I have to make more ideas for experiments so pages can go up more. I have to publish more pages than everybody else on earth put together because I am screaming into a megaphone that I want to go to the science meetings.

[Anonymous No.15181954]

>>15181946
>>ideas for Maid Space counting books:
>count to sprites
>count to national flags
>count to maids
>write more so the display layer can show how Maid Space Operators get formed by Successor Function.

With the smallest possible dimensions and radix for the counting ones, otherwise data is too big.

One of the books I will take a small NES sprite and try to change it to a maid and then count to that maid to show a Maid Search counting to a maid and also answer what is the smallest anime maid?

[Anonymous No.15181990]

How can I understand and master, as a dumbass, the Feynman's integration technique?

[Anonymous No.15182182]

If I was standing on the surface of the earth, and it's radius began decreasing( but I stayed floating where I was) does the force of gravity on me decrease as the mass gets further away? or is that offset by the mass behind the center getting closer?

similarly, if I was stuck to the surface as it decreased, would that make gravity stronger since I'm getting closer to all the mass?

and finally, is there like, an ideal density where the effects of gravity are negligible if you scaled some body up really large? like if the mass of the earth was distributed to the radius of the solar system, and I was on the 'surface' would it be near weightlessness?

[Anonymous No.15182468]

Literally every recommend probability book on the wiki has >50 problems per chapter, I aint gonna do all of that. Is there any good probability book with smaller set of exercises?

[Anonymous No.15182481]

>>15182182

[math]F_{gravity} = \dfrac{G M_{earth}}{r^2}[/math]

> does the force of gravity on me decrease as the mass gets further away?
Yes, r increases so the force F decreases
> if I was stuck to the surface as it decreased, would that make gravity stronger since I'm getting closer to all the mass?
Yes, r decreases so the force F increases
> if the mass of the earth was distributed to the radius of the solar system, and I was on the 'surface' would it be near weightlessness
Yes. The density of the Earth does not matter, only it's total mass. So if the Earth suddenly turned into a black hole the gravity you experienced would not change since the r distance is calculated between you and the Earth's centre of mass. So if the CoM is half a solar system away the force you feel would be nearly zero.

[Anonymous No.15182485]

>>15182182
>does the force of gravity on me decrease as the mass gets further away?
no, at least not in the case you are describing
>or is that offset by the mass behind the center getting closer?
gravity pull doesn't change so nothing is offsetting anything
>if I was stuck to the surface as it decreased, would that make gravity stronger since I'm getting closer to all the mass?
yes, not because you are getting closer to the mass itself, because if from the start you are already in contact with it then you are literally as close as you can be from the get go. it happens because you are getting closer to the center of gravity, which should also answer your questions above
>an ideal density where the effects of gravity are negligible if you scaled some body up really large?
it has very little to do with density, at least not directly. gravity comes from mass and mass only, but the force you feel will obviously be altered by your distance to the center of gravity of the body. so if you shrink an object without changing it's mass, then the pull of gravity will be the same, but the difference now is that you can get closer to its center of mass so if you close that distance you will indeed feel an increase of its gravity over you
>like if the mass of the earth was distributed to the radius of the solar system, and I was on the 'surface' would it be near weightlessness?
if you have a body as large as the radius of the solar system but with the same mass as earth and also with the same center of mass as the earth, then you would feel the same pull from gravity from it as you would feel in that same position right now with the earth at it's current size

>>15182481
>Yes, r increases so the force F decreases
keep in mind that in his first scenario only the radius of the body decreases, but his distance to the center of mass remains the same. so the force applied on him does not change in the end

[Anonymous No.15182487]

>>15182182

[math]F_{gravity} = \dfrac{G M_{earth}}{r^2}[/math]

> does the force of gravity on me decrease as the mass gets further away?
No, r remains static so the force does not change.
> if I was stuck to the surface as it decreased, would that make gravity stronger since I'm getting closer to all the mass?
Yes, r decreases so the force F increases
> if the mass of the earth was distributed to the radius of the solar system, and I was on the 'surface' would it be near weightlessness
Yes. The density of the Earth does not matter, only it's total mass. So if the Earth suddenly turned into a black hole the gravity you experienced would not change since the r distance is calculated between you and the Earth's centre of mass. So if the CoM is a solar system away the force you feel would be nearly zero.

[Anonymous No.15182567]

>>15182487
im not sure if the answers you posted are correct, but the logic is flawed, or at least missing a few steps. the formula you posted is for a point mass. you have to show that the mass of the earth (or any sphere with a density that only depends on radius) could be replaced by a point and the force at the surface would remain unchanged.

[Anonymous No.15182576]

>>15182567
That is already proven using the center of mass or center of gravity equations. Any body no matter it's shape is equivalent to a point mass at some specific location.

[Anonymous No.15182583]

>>15182576
>That is already proven using the center of mass or center of gravity equations.
im sure it is, but maybe you could have mentioned that in your answer.

[Anonymous No.15182584]

What are the ideals of R⊕R? I think its 0⊕0, R⊕R, 0⊕R, and R⊕0, but im not sure how to prove it.

0⊕0 and R⊕R are trivial, i guess they just follow frm definition, but how do u show the only other one is 0⊕R or R⊕0?

[Anonymous No.15182628]

is this correct?

[Anonymous No.15182629]

>>15182584
all the ideals of a "direct sum" of rings [math]R \oplus R[/math] are of the form [math]I_{1} \oplus I_{2}[/math], where [math]I_{1},I_{2} \subset R[/math] are ideals. these are in fact the only ideals of the "direct sum". the proof follows somewhat directly from the definition of ideal, and considering the existence of elements [math](0,1),(1,0)[/math] (so you need a unit in [math]R[/math])
if by R you mean [math]\mathbb{R}[/math] then your result follows by virtue of [math]\mathbb{R}[/math] being a field. if however it is supposed to be an arbitrary ring then it's not true because the statement above holds, as long as [math]R[/math] has a unit at least

also, formally speaking, unless you explicitly want to work with these objects as [math]R[/math]-modules then you probably want to refer to the direct product [math]R \times R[/math] instead. a direct sum is formally not defined between unital rings in the first place

[Anonymous No.15182637]

>>15182628
Yes.

[Anonymous No.15182640]

>>15182637
great thanks

[Anonymous No.15182644]

>>15182584
also, if you are only interested in proving those are the only ideals in your specific example, you can analyze the elements [math]i \oplus 0[/math] in an hypothetical different ring and see that the set of the first components defines an ideal in [math]\mathbb{R}[/math], which once again only has 2 ideals because it's a field

[Anonymous No.15182649]

>>15182644
>hypothetical different ring
hypothetical different ideal*

[Anonymous No.15182689]

I need some help from a Swedish anon. I'm a senior high school student from Hungary, and I'm looking to apply to Swedish universities for my bachelor's degree, and I'm a little confused about the course requirements. It says that I need the equivalent of "biology 2, chemistry 2 and mathematics 4."
What do these numbers mean? Because in Hungary, we have two subject levels (Intermediate and Advanced), and I have to decide on the levels of my maturation exam in a week and I'm not sure if I qualify for application with intermediate biology and chemistry and advanced math, but doing all three on advanced level is completely unrealistic (which is kind of on purpose in the Hungarian system, you are only supposed to learn two subjects on advanced level.)
Can any Swedes in here help me out?

[Anonymous No.15182733]

How do i minimize
[math]
||\vec(y) - a\vec(x) - b\vec(z)||^2
[/math]
with respect to scalars a and b?

[Anonymous No.15182752]

>>15182733
[math] ||\vec{y} - a\vec{x} - b\vec{z}||^2 [/math]

[Anonymous No.15182837]

am i retarded or isn't this just flat out wrong?

[Anonymous No.15182842]

>>15182837
no, you're retarded

[Anonymous No.15182844]

>>15182837
the former

[Anonymous No.15182919]

why is a ring called ring?
why is a field called field?
why the fuck is a magma called magma?
same questions holds for other structures (in my language a division ring is called a "body", a manifold is called a "variety")

Im thinking that there is some sort of intuition behind those names

[Anonymous No.15182995]

>>15182844
>>15182842
it's just that i'd normally intepret that as 7(3/4) not 7 + 3/4. its their fault using shit notation

[Anonymous No.15182999]

>>15182995
mixed fractions are actually written that way

[Anonymous No.15183002]

>>15182919
>Im thinking that there is some sort of intuition behind those names
there usually is not, most of them really just come from the people who came up with the definitions and their own interpretations of those objects, as they were first conceived in their earliest forms. it's as if you were to come up with a word as an inside joke with your circle of friends and later on it starts spreading out and more people begin using it. it might be a convenient word that describes something useful, but without the specific context of what you were doing when you came up with it it's not really helpful to try and figure out how it came to be
>in my language a division ring is called a "body", a manifold is called a "variety"
i know that the difference comes because some countries adopted the name from the german Zahlenkörper (and eventually just Körper) which refers to a body of numbers, and later on an american mathematician decided to refer to them as fields instead for whatever reason so that ended up sticking in english speaking countries. eventually some other languages like spanish and to a lesser extent french ended up adopting both terms, but as for the actual intuition behind them, there's probably none anymore unless you are Dedekind/the other dude and can explain what was going through your head at the time. as for the variety part, it does share a fair amount of similarities with the term "variety" in english, as they both refer to structures whose properties are generally only defined and studied locally through the means of local maps to affine objects (affine (euclidean) spaces in the case of manifolds, affine varieties in the case of algebraic varieties). i imagine that word was used as an analogy to the algebraic structure

[Anonymous No.15183020]

>>15169850
Good Afternoon /Sci/entists

I am working more on my Maid Space book. I am making a page that explains the notation and typesetting, so I made like a reference Maid Space and it has problems. Please see attachment.

First problem it has is that the squares got crooked. Second problem it has is that the writing won't let me put a space. Third problem it has is that it is too fat and not tall enough.

How can I make the squares stop being crooked and make the writing get spaces and make it taller so it looks like a box?

Thank you /sci/entists for reading my post.

[Anonymous No.15183059]

>>15182999
yeah i guess but i dont think anyone ever uses them outside of elementary school t b h

[Anonymous No.15183209]

>>15183208
I made a new thread.

[Anonymous No.15184646]

>>15172000
The checklist is different for everyone. You can only find out your own checklist yourself through trial and error.