/sqt/ - Stupid Questions Thread

[Anonymous No.9325077]

[Anonymous No.9325081]

>>9325077
Why is it that if a person wants to have consensual sex with animals for pleasure it's a crime and that person has a mental condition, but when the person wants to mutilate their dick and believes they are a woman, born in a mans body, and want to fuck dudes for sexual pleasure its not a mental condition?

Why is it that if I wanted to be labeled as a carrot people would assume I have a mental condition and would not prescribe to this notion but they would to above?

Why didn't Hitler succeed?

Why was I born into a generation that has created a society in which everyone thinks their opinions matter, even when they are not warranted?

When will we all be killed by an asteroid or comet?

[Anonymous No.9325085]

>>9325077
whats (1+8)3+1? Im trying to help my son and he says im doing it wrong

[Anonymous No.9325091]

>>9325077
>Why do people want to have sex with animals? And why would anyone chop their dick off?
>Why is it that if I wanted to be labeled as a carrot people would assume I have a mental condition and would not prescribe to this notion but they would to above?
Because I don't think you will taste very nice.
I ponder this over my own existence and ts meaning
>Why didn't Hitler succeed?
because his balls were blown off
>Why was I born into a generation that has created a society in which everyone thinks their opinions matter, even when they are not warranted?
I don't think my opinion matters, so does alot of other people.
>When will we all be killed by an asteroid or comet?
You will know when the time comes

[Anonymous No.9325094]

>>9325085
that's such a horrible way to set out an equation, needs to be more concise other wise it could be anything

[Anonymous No.9325106]

>>9325077
Does photoeffect create voltage in a circuit? One source tells me it only frees the electrons and thus makes the material conductive, other tells me it creates voltage that has to be countered by some other source. what is it?

[Anonymous No.9325110]

>>9325085
PEMDAS, left to right.

[Anonymous No.9325126]

Why are there constants in everything?

[Anonymous No.9325128]

>>9325085
(((1+8)*3)+1)
((9*3)+1)
(27+1)
28

[Anonymous No.9325135]

Who started the Calculus by Spivak meme?

[Anonymous No.9325140]

What kind of bacteria would make ketchup go bad yet taste sweeter?

[Anonymous No.9325153]

>>9325085
28

[Anonymous No.9325167]

>>9325153
kys

[Anonymous No.9325200]

Let's say I have a long text, or a lot of sentences. How do I write a computer program that can derive its context?
I know computers cannot actually understand sentences, but they can probably pick up on certain words to understand the "topic" of a sentence.
How is this done? /g/ is too dumb for this btw, and so am i

>>9325081
>Why didn't Hitler succeed?
He was too ambitious for his own good. Killing Jews in your own country is one thing, every place probably did that with their minorities anyway. But invading other countries is another thing. At some point, the good ol' USA had to step in and beat Hitler down so hard he commited suicide like a bitter soy boy
>Why was I born into a generation that has created a society in which everyone thinks their opinions matter, even when they are not warranted?
Why do you think your opinion about society matters?
>>9325085
>(1+8)3+1
Syntax Error

[Anonymous No.9325375]

>>9325200
>At some point, the good ol' USA had to step in and beat Hitler down
>mfw this is unironically written in american history books

[Anonymous No.9325409]

>>9325077
Let A be set of odd numbers
Which axioms should I use to prove that A exists, and that 3 is in A?

[Anonymous No.9325415]

>>9325128
>>/pol/

[Anonymous No.9325416]

>>9325077
how much milk does it take to make a fridge

[Anonymous No.9325453]

I'm not an aerofag, I was just wondering this.
Imagine a helicopter (one main rotor and one tail rotor).
The tail rotor has a fixed reducing gear such that when the main rotor is producing torque tau, the tail rotor is countering with -tau.
Instead of a rudder, this helicopter has a CVT between the tail rotor's reducing gear and the tail rotor itself. The CVT varies between 1-b and 1+b at the control of the pilot's feet. When the pedals are in normal position, the CVT has a ratio of 1.
Will decreasing and increasing the CVT ratio allow the torque difference to yaw the aircraft? Can the pilot change heading on the spot like with a rudder?
What values of b would give the craft a maximum turn rate typical of a GA helicopter with similar dimensions?

[Anonymous No.9325475]

here's a tough one

[Anonymous No.9325476]

>>9325085
26

[Anonymous No.9325480]

WTF is "Thyr" since it's apparently not a typo?

[Anonymous No.9325481]

Are waves 1 dimensional?

[Anonymous No.9325503]

>>9325081
>consensual sex with animals
Doesn't exist we can't establish a stable mode of communication with animals meaning we can't decide whether they consent or not, so all bestiality is also rape as result. Anyone who fucks animals is mentally deficiant, if someone wants to mutilate themselves that's their peroggative, as long as they aren't an immediate danger to the community they don't need to be in a loony bin

>carrot people
Not the same. Studies have shown that female and male brains are fundamentally sexually dimorphic, meaning their brains just work differently. soem people are literallty born with a female brain in a male body, external to how they identify themselves. Because of this it allows people to identify as the other gender as it is a possibility that their mind literally is.

>Why didn't Hitler succeed?
went for russia too soon

>everyone thinks their opinions matter
infantilisation

[Anonymous No.9325507]

>>9325481
if they're polarised maybe

[Anonymous No.9325523]

>>9325475
It looks horrible, it's all just dirty tricks
https://math.stackexchange.com/questions/113295/pdf-of-a-quotient-of-uniform-random-variables

[Anonymous No.9325543]

>>9325507
Thanks

[Anonymous No.9325760]

What is the definition of a saddle node bifurcation in terms of derivatives? I can't seem to find a nice answer.

[Anonymous No.9325771]

>>9325760
the eigenvalues of the hessian matrix have mixed signs.

if they are all positive it's a local minimum. if they are both negative it's a local maximum.

[Anonymous No.9325828]

>>9325481
depends on the wave,longitudinal waves can be one dimensional as they oscillate over and back parallel to the motion of the wave.
>>9325507
Transverse waves when polarised oscillate perpendicular to the motion of the wave so they can only ever be two dimensional

[Anonymous No.9325885]

>>9325523

Thoughts on this one?

[Anonymous No.9325894]

>>9325771
What about in the 1D case? Sorry, I should have been more specific.

[Anonymous No.9325903]

What are the steps to solving this type of problem?

This is a problem I put together that is similar to one I need to solve. We very briefly went over this right before thanksgiving break, so it's all a bit fuzzy to me now. And we did not do a problem where you add the two sums. We only did one where you subtracted them.

I would really appreciate it if you could go step by step on this. We're not allowed to use calculators on anything for this class, so just putting it into a calculator to find the answer isn't an option for me.

[Anonymous No.9325904]

>>9325885
Why don't you try actually learning the material for the class you're paying hundreds of dollars for.

[Anonymous No.9325911]

>>9325904

I am a lazy degenerate so I like to learn things the day before the exam, for assignments before that I like to just try to hack the answers off of the internet somehow because I can't be dicked

also I'm not in burgerland so I'm not paying out of my cock for tuition

[Anonymous No.9325918]

Can someone break down Spectrophotometry with UV light? Something about 2 amino acids, Tryptophan and Tyrosine. I'm struggling with this shit.

[Anonymous No.9325924]

>>9325903
sum_{i=5}^28 (3*5^i+1) =
3*sum_{i=5}^28 5^i + sum_{i=5}^28 1 =
3*(sum_{i=0}^28 5^i - sum_{i=0}^4 5^i) + sum_{i=5}^28 1
then apply geometric series formula

similarly for sum from 30 to 300

[Anonymous No.9325929]

>>9325885
What have you tried?

[Anonymous No.9325937]

>>9325911
you're not learning anything, you're literally just trying to get answers fed to you and think you will be able to do something with that.

[Anonymous No.9325940]

You have a brick sitting on a table. I read in a physics book that there is atmospheric pressure pushing down on the top face of the brick and that there are small pockets of air underneath the brick (between it and the table) that exerts atmospheric pressure upwards to balance out the downward force.

If you place a brick on a table and then somehow suck all the air out from underneath it, would the air pressure on top smash the brick through the table? Are there any experiments or demonstrations of something like this happening?

[Anonymous No.9325948]

>>9325929

a)

Idk if I should approach it using the expected value of a poisson or an exponential. Really only a) I have an issue with, b) is easy.

I'm also not sure how to substitute in the Poisson variable. Like how the fuck does mans fit pic related into that shit.

>>9325937

I mean I've tried to do it but I'm literally clueless. Idk I just hope someone has encountered a similar problem

[Anonymous No.9325956]

>>9325894
>>9325771
>>9325760
sorry mate, I'm a faggot.
I thought saddle node bifurcation meant something else because they're similar in my language.
Disregard my posts.

[Anonymous No.9325958]

>>9325200
>He was too ambitious for his own good. Killing Jews in your own country is one thing, every place probably did that with their minorities anyway. But invading other countries is another thing. At some point, the good ol' USA had to step in and beat Hitler down so hard he commited suicide like a bitter soy boy

[Anonymous No.9325975]

How do I approximate zeroes of a function?

[Anonymous No.9325985]

>>9325940
>would the air pressure on top smash the brick through the table?

up to a point. Not through the table, but it would mash it with the table.

Literally imagine a vacuum bell jar. You don't need it to be a brick, the same principle applies.

The more you suck air out of the jar, the more the pressure difference pushes it into the material it's sitting on. Likewise the air pressure from beneath the table would push the table inside the jar.

I think it would help if you imagined something less rigid. Say a trampoline.

You put the jar on top of it, nothing happens. You start sucking the air out of the cavity and see what happens. Or place a plastic bag on your mouth and inhale.

[Anonymous No.9325986]

>>9325975
https://en.wikipedia.org/wiki/Newton%27s_method

[Anonymous No.9326035]

>>9325985
Ah, so the air pressure under the table would push the table up into the brick and they would get kind of mashed together? If the table is weak enough couldn't it break? But it would break from the squish of a top and bottom force not just from one side.

I like the bell jar and trampoline analogy...you suck the air out and the air pressure upward stretches it up into the jar.

[Anonymous No.9326076]

Why are there no high speed automatic doors?
They all crawl, you'd think we'd be far enough to make the fast and safe.

I couldn't even find some for my store even when willing to pay extra.

[Anonymous No.9326078]

>>9326035
>Ah, so the air pressure under the table would push the table up into the brick and they would get kind of mashed together?

yep, if the material allows that it's possible. Imagine you pressing a fork on carton. The fork starts to get embedded in the carton.

>If the table is weak enough couldn't it break? But it would break from the squish of a top and bottom force not just from one side.
yeah the table could break, but remember that air pressure can only create a force equal to the difference in pressure*surface. So for a given surface there is a limit to the force.
Now if you take a very wide vacuum jar, chances are the stress from the torque at the center of the circle could be enough to break the table. A small vacuum jar wouldn't break the table not only because there would only be a small total force but also because there wouldn't be enough torque to deform the table.

[Anonymous No.9326095]

What happens in a class about Ordinary Differential Equations? It's not required for my math degree, but I can take it if I want. What sort of applications does it have? I'm thinking about doing Math/CS.

[Anonymous No.9326101]

Anyone know how to answer 2? I haven't a clue

[Anonymous No.9326126]

is ME a meme to major in, I'm in EE right now, and this digital system class I have is killing me badly.

[Anonymous No.9326189]

>>9325077
Why are there so many frog and feels threads on /sci/?

[Anonymous No.9326293]

If C is a C^2 curve of the plane, how can you see on its graph that its partial derivative with respect to y is equal to 0 ?
Will it mean that the curve becomes almost vertical ? or almost horizontal ?

[Anonymous No.9326329]

What is the excel sheet graph called? A simple 2d graph?

[Anonymous No.9326395]

what do we do with these people?

[Anonymous No.9326398]

>>9326095
I hardly remember anything from ODEs. There's a lot of applications but typically I've found you can just pick it up as you go along. ODEs is the closest thing in math to a biology type course...in that you're learning closer to "what" knowledge rather than "how" knowledge. You learn about different kinds of differential equations and the tricks to solve them. Then you forget it all until it comes up in a real problem again somewhere and you look up the trick for how to solve it again.

I wouldn't really recommend taking it. Just teach yourself how to do the separation of variables technique and you're good. Learn the rest on the fly as you come across them (if you ever do). The professor can make or break any class though...if it's known to have to very good professor then maybe take it.

[Anonymous No.9326405]

>>9326101
m1v1 + m2v2 is conserved

[Anonymous No.9326414]

How do you execute "retrieval practise" for math?
What's your method?

I would love to get a bit more braingains.

[Anonymous No.9326430]

>>9326095
>What happens in a class about Ordinary Differential Equations?
lots and lots of dirty tricks
ODE exams are the worse, usually you either see/know the trick and solve trivially, or you don't and there's pretty much no method to save you

it's pretty useful I guess

[Anonymous No.9326436]

>>9326398
>>9326430

Ok thank you. I do know separation of variables. I'll probably skip the class if it's never required for anything.

[Anonymous No.9326443]

>>9326395
Let natural selection work her course

[Anonymous No.9326446]

>>9326405
yeh i get that but not the friction and distance bit

[Anonymous No.9326453]

>>9326101
Need elastic collision equation. To do with conservation of momentum

[Anonymous No.9326473]

Im trying to use CFX to model a flat plate in a wind tunnel at 10m/s

why is my force on the plate -8.8e-6 N?

[Anonymous No.9326476]

>>9326473

[Anonymous No.9326695]

I'm trying to make similar questions like this so my students can practice these types of questions on their upcoming AIR test. Can someone help me come up with some examples that work out to reasonable ratios like (1/3, 1/4/ etc. no radicals)

Sample Question: "Line segment AC has endpoints A (-1, -3.5) and C(5,-1). Point B is on line segment AC and is located at (0.2, -3).
What is the ratio of AB/BC?"

Which if you work out the distance formula and divide the two results you get 0.25 or 1/4th.

Assistance would be greatly appreciated. I feel like a brainlet.

[Anonymous No.9326855]

>>9325167
kys

[Anonymous No.9326858]

>>9325167

[Anonymous No.9326862]

>>9326695
Dog, you're a math teacher?

[Anonymous No.9326879]

>>9326862
yessir

[Anonymous No.9326932]

>>9325077
How do I start working in academ?
Is starting as a tutor a good idea? how do I become one ( I am studying in germany)

[Anonymous No.9327258]

I get homology which is treating holes of varying dimensions like sub-manifolds mostly when it stops manifold from being smooth.
but wuts cohomology?

[Anonymous No.9327268]

What is 1+1?

[Anonymous No.9327277]

>>9325077
What does d/dx represent? I know it means derivative with respect to x and dx is supposed to represent an infinitesimal but what is just d?

[Anonymous No.9327299]

>>9327258
nevermind

[Anonymous No.9327327]

>>9327277
it's an operator.
if just returns the answer to the question: "how much does [insert function] change with an infinitesimal change of x?"

[Anonymous No.9327514]

>>9326453
What is that

[Anonymous No.9327516]

>>9327514
it's a wrong statement from someone who doesn't know what they're talking about.

elastic collision means that in addition to conservation of momentum at impact, there is also conservation of energy. Very wrong to assume that in the case of the collision of two cars, plus this is a very academic exercise where you're told exactly what you can assume or not.

[Anonymous No.9327569]

>>9327277
If you consider the infinitely differentiable functions over an open set (call this set of functions A) , then d/dx usually means the map from A to A such that it maps f to f'.
If you consider A as a vector space over R, then d/dx is linear.

[Anonymous No.9327632]

>>9327516
So what am I supposed to do?

[Anonymous No.9327645]

Can non electromagnetc field who vibrate at 430-700THz become visible light? like airwaves for example?

[Anonymous No.9327667]

Is Wolfram fucking with me?

[Anonymous No.9327684]

>>9327667
The [math]-e^x[/math] can be put into the [math]c_2[/math] part

[Anonymous No.9327686]

>>9327667
It's also usually dependent of the way you calculate the particular solution whether it includes an (unnecessary) homogenous part

[Anonymous No.9327699]

>>9327684
>>9327686
i see

[Anonymous No.9327776]

does she have FAS? i can't figure out how to recognize it. those cartoon illustrations aren't very helpful.

https://www.youtube.com/watch?v=VXXjpih0AZM

[Anonymous No.9327873]

Not really sci related but could someone explain to me what's the difference between the used of present continuous and going to+the infinitive? When do I use each of them and how can I distinguish between them?

[Anonymous No.9328158]

>>9327873
Present continuous is used when you've decided in the past you will do something and then that time is coming up, so you say "Tomorrow, I will be doing X"

Going to means something that will happen just based on current evidence. "It is going to rain today because the clouds are grey."

The truth is that they can be used interchangeably. "Tomorrow I am going to do X" sounds normal. Don't sweat on it. They're virtually the same.

[Anonymous No.9328163]

what the FUCK does a fractional derivative represent geometrically?

[Anonymous No.9328295]

what do I do if there's a negative sign in front of two factors?

-(x-3)(x+1)
do I just negate the first term? Negate them both? Do I factor before I negate?
just, how am I supposed to interpret this?

[Anonymous No.9328301]

>>9328295
-(x-3)(x+1) =
(3-x)(x+1) =
(x-3)(-x-1)

[Anonymous No.9328320]

>>9325480
thyroxin

[Anonymous No.9328343]

>>9328295
-ab = (-a)b = a(-b)
Also, it's better to leave your expression this way, since it's the most "proper" form of it.

[Anonymous No.9328351]

>>9326095
>Math/CS

[Anonymous No.9328352]

[math] 2x2= 2^2[/math]

[Anonymous No.9328359]

[math]sum_{i=5}^28 (3*5^i+1) =
3*sum_{i=5}^28 5^i + sum_{i=5}^28 1 =
3*(sum_{i=0}^28 5^i - sum_{i=0}^4 5^i) + sum_{i=5}^28 1[/math]

[eqn]sum_{i=5}^28 (3*5^i+1) =
3*sum_{i=5}^28 5^i + sum_{i=5}^28 1 =
3*(sum_{i=0}^28 5^i - sum_{i=0}^4 5^i) + sum_{i=5}^28 1[/eqn]

[Anonymous No.9328362]

>>9326095
You learn how to solve certain kinds of equation.
It's essentially memorizing tricks for the most part.
Not really math.

[Anonymous No.9328373]

>>9328359
sum should be \sum and it's better to write \sum\limits_{i=m}^{n} instead of just \sum_{i=m}^{n}
Also, you don't need to type * if you don't actually want it to appear as a symbol. Just type ab for "a times b".

[Anonymous No.9328383]

>>9328373
>Also, you don't need to type * if you don't actually want it to appear as a symbol. Just type ab for "a times b".
How do you distinguish "3 times 5 to the power of i" from "35 to the power of i"?

[Anonymous No.9328385]

>>9327268
define 1

[Anonymous No.9328393]

>>9328373
>it's better to write \sum\limits_{i=m}^{n} instead of just \sum_{i=m}^{n}
Why?

[Anonymous No.9328399]

>>9328393
[math] \sum\limits_{i=m}^{n} [/math]
vs
[math] \sum_{i=m}^{n} [/math]
or just use eqn tags

[Anonymous No.9328416]

I'm trying to prove that if a function F from the Euclidean plane to itself is bijective and maps convex sets to convex sets, then it is an affinity.
I'm using the fact that there are only a finite kinds of sets for which both the set and its complement are convex, but I'm stuck. I've worked out that F must map a halfplane with a ray on its border to a halfplane with a ray on its border, and that the starting point of the ray is mapped to the starting point of the ray in the image.
I could use a hint on how to progress.
Sorry for muddy terminology, ESL.

[Anonymous No.9328423]

>>9328362
>>9326398
>>9326430
Why don't more schools teach ODEs without turning it into a cookbook style class?

[Anonymous No.9328428]

>>9328423
my prof did that and the physics students that shared the class with mathematicians chimped out about it.

[Anonymous No.9328437]

>>9325077
why is the big crunch uncredible wrong?
>still expanding
maybe we're still in the early stages of the universe. maybe it will get drawn back in over time.

[Anonymous No.9328439]

>>9328383
[math]5^i3[/math] but i’d ignore just about everything that anon said after “\sum” if I were you

[Anonymous No.9328530]

>>9327776
she looks qt, only a strong jawline and wide cheekbones
no low nose bridge, round face or large pupillary distance that would suggest FAS
pic related is what FAS looks like

[Anonymous No.9328588]

I understand most of the concepts but make small minor mistakes in calculations and so on and feel a lack of intuition.

What's the best way to git gud and develop these skills in a mathematical sense?

[Anonymous No.9328592]

Why do mathematicians get triggered if you use local coordinates in differential geometry? I'm trying to learn it properly so I can start with general relativity, but many people recommend to avoid them. If you can make more general claims about some manifold not using some explicit construct, that's alright, but I want to learn to solve specific problems. And fuck differential geometry/topology books.

[Anonymous No.9328599]

>>9328592
>differential geomtry/topolgy for physicists books

[Anonymous No.9328631]

>>9328592
why do you care what people think ? just do your thing
manifolds are constructed so that you can use local coordinates, so go nuts

[Anonymous No.9328637]

When finding the inverse of a 2x2 matrix using row operations, are there multiple ways you can get the identity matrix on the left side?

I've found the correct inverse of the matrix, but I've also done it through row operations and got a different answer...

[Anonymous No.9328641]

>>9328637
you can do it in several ways, but there's only one inverse

[Anonymous No.9328643]

>>9328637
Check if the matrices you got actually produce the identity matrix when multiplied with the original matrix.

[Anonymous No.9328648]

>>9328637
(1/ac-cd)*[d,-b;-c,a] is how I do it

[Anonymous No.9328656]

>>9328637
(1/ac-bd)*[d,-b;-c,a] is how I do it

[Anonymous No.9328660]

suggestion on books to learn biology and biochemistry for a totally brainlet? (89 IQ)

[Anonymous No.9328676]

>>9328383
\cdot

[Anonymous No.9328679]

How come fluoride isn't more common and/or important in our surroundings?
Carbon,Nitrogen and Oxygen are very similar to it and without them there would be no organic matter, atmosphere or life itself.
How come Fluoride is different?

[Anonymous No.9328683]

>>9328679
*Fluorine, im not a native speaker sorry

[Anonymous No.9328690]

>>9328679
because it has almost a full octet so it reacts with everything

[Anonymous No.9328699]

>>9328637
If you mean ways in various ways with GJ-elimation, then yes. But there's only on inverse and there are multiple "ways" to get identiy matrix. As long your operations are giving you (correctly) the identiy matrix and you use the same operation on them, you get the one and only existing (if there's on) inverse matrix A^-1.

[Anonymous No.9328704]

>>9328631
Well I care if it's my professors.

[Anonymous No.9328709]

How does college work?
I want to eventually learn all that I can learn, get a PhD, and work in research and development. But the more time I spend in college, the more I feel like I don't know what college is or if I'm doing anything right. From what I understand, I have to get my Master's degree first, and my advisor told me that I have to speak to one of the professors in the biology department to apply for the Master's program. I don't know what they mean by "program" or why I have to "apply" and not simply just register, or what I need to do for my application to be accepted, or what I'm going to be doing as part of the "program" at all. Also, what do I need to say to the professor? What do I ask them?
I also was told that I need to do research to get my bachelor's degree before I can get my Master's degree, and I don't know how to do that. I talked to one of the biology professors and asked them if I could do research with them. He told me that he normally doesn't want students working in his lab if they can't be there for several years, and I'm a senior with only one semester left. I told him that I still have classes that I need to take and will be here for at least one more year, and that I was pursuing my Masters degree, and he said he would consider it and that I should contact him shortly before the start of the spring semester. What will the research involve? What do I say to him when I contact him? How was I supposed to do the research normally?
I assume the PhD involves something similar and I don't know what that is. Also, what's a thesis, and how, when, why, and in what way do I do one?
I have always gotten consistently above-average grades in all my classes, so the content itself is not the problem; I just never really understood the syntax behind the educational programs themselves and I feel completely lost.

[Anonymous No.9328722]

>>9326695
Calculate the Vector AC
Multiply by a scalar (e.g. 0.8)
Add that new vector to A to get your B

It will work out nicely with basically any "nice" factor between 0 and 1

[Anonymous No.9328732]

>>9328399
I used $$ $$ a thousand times because I didn't know you could do it like this...

[Anonymous No.9328735]

>>9328709

https://www.youtube.com/watch?v=WGoTmNU_5A0

[Anonymous No.9328737]

>>9328383
powers have higher priority than multiplication. If you want (ab)^n then you need brackets, ab^n = (a)(b^n)

[Anonymous No.9328740]

Is the homotopy group of a kan complex isomorphic to the homotopy group of its geometric realization?

[Anonymous No.9328829]

>>9325077
Here's one for you, I have 4000 lines of raw data from a single thermocouple.
How do I reduce it into 100-200 lines and also interpolate between the ones where the temp only changed 1°C in more cycles so I can do my shitty differential graph calculation for my project?
I am using Libre Calc but I have access to an old machine with Excel 2010.

[Anonymous No.9328839]

>>9325077
red pill me on moment-generating functions

[Anonymous No.9328868]

>>9328660
>suggestion on books to learn biology and biochemistry for a totally brainlet? (89 IQ)
The two best beginner biology books are "Campbell Biology" and "Life the Science of Biology" (Sadava). Pick one.

[Anonymous No.9328895]

In trying to show

Cov(aX + b, Y) = aCov(X, Y) and hence p(aX +b, Y) = p(X, Y),

how do I make the connection "and hence" in the proof? First equation is not difficult

[Anonymous No.9328925]

ARE FRACTIONS UNIQUE TO THE IMPERIAL SYSTEM?

[Anonymous No.9328930]

I'm on IT for 20 years and never found I person to solve this puzzle.
I solved but had to use brute force.

How it works
it is a ATM machine with
10x 20 dollar bills
10x 50 dollar bills

the client asks for 130 dollars
sure the answer is 1x50 and 4x20

also the premise that the higher bills should go first
but I need a fluxogram like this

50 +
50 +
50 (too much, tries next lower bills)
20 +
20 (too much, no more options)
now what?

it obvious for humans, but how to write this for a computer?

not bait

[Anonymous No.9328933]

>>9328829
>How do I reduce it into 100-200 lines and also interpolate between the ones where the temp only changed 1°C in more cycles so I can do my shitty differential graph calculation for my project?

it would help if we knew what your data looks like.

One one hand you want to reduce size and on the other hand you want to increase it?

[Anonymous No.9328939]

>>9328930
whats a fluxogram?

[Anonymous No.9328948]

>>9328933
I have two columns of data, one is time and the other is temp. I need it to be around 100 lines instead of 4000 and smoothed out, temp and related time.

[Anonymous No.9328954]

>>9328948
I meant what does your 1°C thing means, but whatever.

There are tons of downscaling methods.

You can use downscaling using medians.

So you divide your dataset in chunks of 40 points, you take the median of those 40 values, and you obtain your new "value".

[Anonymous No.9328957]

>>9326095
UPDATE:
For some reason, in Linear/Real Analysis/Multi class we did a single PDE.

[Anonymous No.9328970]

>>9328954
Oh, I meant that the data repeats like 591°C for five read cycles (5 entries) then decreases to 590 for another 4 or so. Later it drops more rapidly then again smoothes out.

[Anonymous No.9328973]

>>9328704
Well trust me when the time comes to study some actual examples, you'll have to use coordinates (manifolds are defined by affine charts so if you have to study manifolds, you're gonna use affine charts...). But they're right in that you should avoid them whenever possible because coordinate-free arguments are usually more succinct and cleaner.

[Anonymous No.9328974]

>>9328954
I am also trying to avoid doing this by hand for half a day, I have other important things to do.

[Anonymous No.9328981]

>>9328930
Really sounds like a /g/ question for your intro programming class. Not trying to talk down on your or anything but this is the kind of puzzle freshmen at my college recieve to get them in the cs thinking mode.
I'll post pic of my solution in a second.
>>9328939
From "flux" and "gram" I think it means the same thing as "flowchart."

[Anonymous No.9328986]

>>9328981
I see.

[Anonymous No.9329024]

How do you prove that sound is a wave?

We hear these things called "sounds" and people tell me it's a wave motion through the air into my ear. Why should I believe that?

How can you show that sound travels as a wave?

[Anonymous No.9329026]

>>9328930
>>9328981
I think this is what was intended.

[Anonymous No.9329065]

>>9329026
nice, I will check it

well I forgot to mention that the denominations, their quantity and their values should be a matrix/array

[Anonymous No.9329067]

this might be more /g/ related but do any of you have experience with adding shit to Matlab? I need to read LabChart .adicht files into Matlab and I found some shit that will do what I need on github but I have no idea where to put it. The only instruction is to put the +adi folder into the Matlab path, which doesn't do anything so my guess is that it's not in the right place.

[Anonymous No.9329070]

>>9328895
wtf is p? The correlation?

[Anonymous No.9329081]

>>9328930
if the client wants X = an odd multiple of 10:
>give 50 and go to the procedure for an even multiple of 10.

procedure for X = even multiple of 10:
>give 2*$50 until the remaining amount is less than $100
>give remaining amount as $20 bills.

[Anonymous No.9329092]

If you mated a bull dog and a shitsu, would it be called a bullshit?

[Anonymous No.9329095]

>>9329070

correlation coeffecient

[Anonymous No.9329098]

>>9329081
but you cannot set that and should let the computer make the wisest choice
but the oods/even may be a part of solution

[Anonymous No.9329123]

>>9329098
why can't you?

that's the wisest choice...

>>9329092
it would be a shit dog.

[Anonymous No.9329130]

>>9326395
We used to have this joke, back on Haight street in SF, the LSD tourism capital of the world.

What's dumber than a bunch of homeless hippies selling people rocks?

The yuppies that buy them!

Ppl that are into new-age kundalini chakra bullshit (i.e. /x/) are being fleeced hardcore. It's pushed on normies so that they feel better about themselves while dumping money into things that are dirt cheap, like fucking rocks, or acid that the dealer bought for like 50 cents a hit and marked up 20x. Hell, I saw a chick sell an Italian tourist a single fucking hit for 80 dollars one time. Get a bunch of white people "enlightened" and they're pretty much walking money machines, as long as you bullshit hard enough. It's all a big scam... the GDF makes their living off of these assholes, and it trickles up to the red & whites, the HAs, who pretty much started all that shit back in the 60s. Still exists today, and that's all it's ever gonna be. Tie-dye is a gang color.

t. former lsd chemist. so you cook 7 lbs of rice and spread it on sheet trays, lower your apt heat to 70c, spread it on sheet trays, shut all your windows, strip your mycelium, innoculate, cover, wait a few days, extract, kick the tryptamine over, crystalize, discard the first layer because it's "burned", discard the second layer because it will literally fucking kill you if you touch it, and then you got yourself some family white.

owsley is banned by US chemists for being far more dangerous to make, but with easier reagents, since you gotta make everything from scratch.

other techs are amber, silver, hoffman, rose, fluff. fluff is comparable in yield and ease to make. "needlepoint" is a method of laying into hits, and is not a tech

and yes if you're gonna talk shit about things you don't know, the easiest way to produce LSD is to kick it over from psilocybin. which is readily available to anyone in the PNW. the chemicals used for the strip and kick are secrets,

[Anonymous No.9329137]

>>9329095
Then it should be obvious.
[math] \rho (aX+b,Y) = \frac{Cov(aX+b,Y)}{\sqrt{V(aX+b) V(Y)}} = \frac{aCov(X,Y)}{\sqrt{a^2V(X) V(Y)}} = \frac{Cov(X,Y)}{\sqrt{V(X)V(Y)}} = \rho (X,Y) [/math]

[Anonymous No.9329143]

>>9329137
I made a mistake.
If a is negative, then it is -ρ(Χ,Υ).

[Anonymous No.9329148]

>>>>9329130
tell me some more

t. eclectic salesman paying 1100 for 3 sheets of average (100ug) acid

[Anonymous No.9329214]

X is uniformly distributed over [10, 20]
Y is uniformly distributed over [10, X]

How can i calculate E(Y)?

WHY IS IT not just (X-10)/2? Does that make (E(X)-10)/2) correct?

[Anonymous No.9329223]

>>9326095
> What sort of applications does it have?
Simulation is a major one. Many physical systems are described by ODEs where the independent variable is time (i.e. you have a relationship between the rates of change of various quantities and their current values).

[Anonymous No.9329257]

>>9326095

you remember in high school algebra how you had to find a number that satisfies an equation with a bunch of variables and constants? with ODE's you're trying to find an expression that satisfies a bunch of derivatives in one variable. if there are two or more independent variables then you're solving a PDE. it gets more complicated than that but that's the motivating problem to the subject. the classic example of something from the physical world would would model with a pde would be the diffusion of heat in a rectangular or cylindrical bar

[Anonymous No.9329263]

>>9328592
>fuck differential geometry/topology books

fuck you. most of that shit was made by physicists yet they try to sell it to math students as "muh pure math." it's such bullshit. number theory is the only pure mathematics subject, and even that has been corrupted by modern algebra and fucking galois theory nonsense.

[Anonymous No.9329269]

>>9329263
>number theory is the only pure mathematics subject, and even that has been corrupted by modern algebra and fucking galois theory nonsense.
t. brainlet

[Anonymous No.9329277]

>>9329269

cock sucking algebraist.

[Anonymous No.9329280]

>>9329214
>WHY IS IT not just (X-10)/2?
first you probably meant (X+10)/2
second (X+10)/2 is E(Y|X).

Lucky for you, it just so happens that E(E(Y|X)) = E(Y).
So just go one step further.

[Anonymous No.9329321]

>>9328709
same here. It's kind of a clusterfuck. I guess depending on your field there will be only a few places to work in academ. well, depending on your coutry the master is something you have to apply for and might have less seats then the bachelor. so I guess once you acutally got into the master program the profs will be nicer.
By do research she might have meant your bachelor work which includes some research or she might have said that you have to look into it yourself. hard to understand from what you tell us.

[Anonymous No.9329338]

would you guys share some math memes?

[Anonymous No.9329339]

>>9325077
What mathematical technique would I use to take a series of points on a graph and ascertain the function used to generate them? Didn't stay in school past precalc so I wouldn't know, but I'm guessing this is something calculus would be used for; I just don't know enough about it to know where to begin, so I'd appreciate being pointed in the right direction.

pic unrelated

[Anonymous No.9329341]

>>9325453
Bumpin in hope for response.

[Anonymous No.9329348]

>>9329339
This is generally called "regression." I'm a brainlet so I only know the regression technique for linear functions. But if you websearch for "regression" you'll probably find resources on it.
If you just need to get it done quickly, put the points into excel or a graphing calculator and choose a trendline mode.

[Anonymous No.9329350]

>>9329339
>What mathematical technique would I use to take a series of points on a graph and ascertain the function used to generate them?
You didn't put many restrictions on the kind of function you're talking about here (there's always going to be many functions that work), but I'm assuming you want a continuous function. If it's a finite series of points you can use the Lagrange polynomial to get a polynomial going through each point:
https://en.wikipedia.org/wiki/Lagrange_polynomial

[Anonymous No.9329352]

>>9329348
>This is generally called "regression."
Wrong.

[Anonymous No.9329371]

Is it possible for different eigenvalues of a matrix to produce linearly dependent eigenvectors?

[Anonymous No.9329372]

>>9329350
To illustrate

[Anonymous No.9329374]

>>9329348
It's called interpolation.
Regression is a statistical thing. It is about *approximating* (not exactly Interpolate) something given some data in a simple way (usually linear) so that you can Extrapolate knowledge.

[Anonymous No.9329380]

>>9329339
It's called statistical inference. There are infinitely many functions that produce a finite set of points. It'd be trivial to come up with an n-degree polynomial, for instance, that would produce your n points. If you want to use your function in predicting new points, you will have to avoid overfitting and either use lower degree polynomial or different distributions entirely.

[Anonymous No.9329384]

>>9329374
Thanks for correction.

[Anonymous No.9329393]

>>9329371
No.
Same goes for generalized eigenvectors of different eigenvalues.

[Anonymous No.9329396]

>>9329384
They're similar in a way. I think I was confusing them as well before I learned about them.

[Anonymous No.9329398]

>>9325106
Think it through. If it's knocking electrons out of a material, that region has a positive net charge, so it has a positive voltage relative to the rest of the circuit.

[Anonymous No.9329405]

What is the recommended book for Control Theory? I searched the wiki but didn't find one.

[Anonymous No.9329409]

>>9328679
7/8 octet means far fewer possible compounds

[Anonymous No.9329411]

>>9328690
Yes... but No

[Anonymous No.9329432]

Can I build a homemade icbm with UDMH-N2O4

[Anonymous No.9329439]

Are all ratios dimensionless? It seems intuitive they are but I was just wondering if there are any weird cases where they have a dimension.

[Anonymous No.9329443]

What is an infinite decimal expansion for real numbers? Apparently all reals have a unique infinite decimal expansion but this includes the clause that it can't end in infinitely many zeros. In that case, what would the infinite decimal expansion for whole numbers be?

[Anonymous No.9329446]

>>9329439
>Are all ratios dimensionless? It seems intuitive they are but I was just wondering if there are any weird cases where they have a dimension.
1.20$ / 1 litre of gas

[Anonymous No.9329448]

Why does magnetic force obey a right-hand rule form rather than following the B field lines?

[Anonymous No.9329453]

>>9329443
>What is an infinite decimal expansion for real numbers?
In general, an infinite decimal expansion has the form (in base 10): [math] x=a_0.a_1a_2a_3...[/math] where [math] a_0\in \mathbb{Z}[/math] and [math] a_i\in \{0,1,2,...,9\} [/math] for [math] i>0 [/math], so [math] x=a_0+\frac{a_1}{10}+\frac{a_2}{10^2}+...[/math]

>In that case, what would the infinite decimal expansion for whole numbers be?
1 = 1.000000... = 0.999....
2 = 2.00000... = 1.9999.....

[Anonymous No.9329454]

>>9329446
Good point, I feel like a retard now.

[Anonymous No.9329467]

>>9329453
I see, thank you. Is the clause that the expansion must not end in infinitely many zeros just to make the expansion unique, or are there other reasons as well? I notice that some definitions online opt for the clause that the expansion must not end in 9s.

It's also kinda exciting to finally come across 1 = 0.999... in my studies

[Anonymous No.9329481]

>>9329467
>Is the clause that the expansion must not end in infinitely many zeros just to make the expansion unique, or are there other reasons as well? I notice that some definitions online opt for the clause that the expansion must not end in 9s.
I don't know what notes/book you're reading from but I haven't seen one with such a clause, I assume somewhere down the line that uniqueness will be used though. I've usually seen it noted that certain numbers don't have unique expansions but that you just use whichever one you feel like

[Anonymous No.9329482]

>>9329350
This appears to be precisely what I was looking for. Thank you kindly.

>>9329380
I see what you (and >>9329372) mean. This makes the Lagrange polynomial an ideal solution.

[Anonymous No.9329488]

>>9329467
>Is the clause that the expansion must not end in infinitely many zeros just to make the expansion unique
Yes, it is.

> or are there other reasons as well?
Not really.

>I notice that some definitions online opt for the clause that the expansion must not end in 9s.
That's the the more common and "sensible" choice.

[Anonymous No.9329493]

will i become less of an autist once i finish my engineering degree?

[Anonymous No.9329495]

>>9329481
It's from my in-class notes. I guess my professor defined infinite decimals expansions this way so he could say every real has a unique expansion

>>9329488
Thanks.

We're using A Transition to Advanced Mathematics but the book doesn't cover decimal expansions

[Anonymous No.9329506]

I'm moving at the speed of light relative to the photons in my room. Why hasn't the universe ended?

[Anonymous No.9329531]

>>9325077
If I desperately need to score at least 65 points on a chemistry exam that will contain 4 weeks worth of material I am not familiar with plus some stuff from past 2 tests, is it worth it to stay up all night cramming until the test tomorrow afternoon? Where to start? What should I prioritize ? Help pls

[Anonymous No.9329535]

I know that R ~ (0,1), where R is the real numbers and (0,1) is the interval from 0 to 1. How can I show that R x R ~ (0,1) x (0,1)?

[Anonymous No.9329537]

>>9329531
Worth? Dunno. You just can say that if you tried.
But there's no shame in trying. So let's try.

>Where to start?
Organize material, then sort it. Assignments, notes, ...
Make maybe a excel table with the topics you covered in class and think about what's more likely test-relevant and what's not.

>What should I prioritize?
Of course what will pop up most likely in the exam. To know that past papers are a good start for a quick reference, mark then in your excel table and go through the material. Doesn't make sense? Make sense of it. Google it.

Try to retrieve the material in some intervals. 10min, 30min, 60min or whatever you think is a good idea. Mostly draw the ideas and concepts on empty paper out of memory. Attempt do to the test questions and explain the material for yourself on a paper. Do some more problems if you have any and more questions.

[Anonymous No.9329552]

>>9329535
I am a dummy. If A ~ B and C ~ D then A x C ~ B x D

[Anonymous No.9329555]

what formula do i use to find the speed of an object at certain location with a constant force applied to it?

[Anonymous No.9329556]

>>9328930
50+50+50 (too much)
50+50+20+20 (too much)
50+20+20+20+20 (solved)

you iterate through each possible combination until you go past the target or you hit the target

easiest way to do this would be to use a stack (like in real life you would have a stack of dollar bills) or recursive function calls (implicit stack)

[Anonymous No.9329558]

>>9329024
"I'm curious, so I'll go investigate and find out."
~ normal intelligent person

"I dare you to make me learn."
~ brain-damaged retard

[Anonymous No.9329565]

>>9329555
f=ma

[Anonymous No.9329579]

>>9328930
the simplest answer would be to work backwards and only use larger bills when your remaining balance to give the client is a multiple of a larger bill.

so basically
130 checks if 130 is a multiple of 50. no
-20 checks if 110 is a multiple of 50. no
-20 checks if 90 is a multiple of 50. no
-20 checks if 70 is a multiple of 50. no
-20 checks if 50 is a multiple of 50. yes
-50

[Anonymous No.9329580]

>>9329537
Thank you dearly anon. I’ll give it my best. Will post back with results

[Anonymous No.9329595]

>>9329565
i'm having trouble figuring out how to apply that to a problem like this:

In outer space, an object whose mass is 60kg is subject to a constant net force <13,-9,12>n. When the object is at location <10, 6, -4>m, its speed is 0.8m/s. When the object has moved to location <13,8,-2>m, what is its speed?

[Anonymous No.9329603]

>>9329595
remember that a=(m/s)/s

[Anonymous No.9329606]

>>9329558
The post wasn't supposed to have been accusatory in tone in any way. I just thought it would be interesting to start a discussion about sound waves.

[Anonymous No.9329614]

>>9329595
doesnt make sense unless you know what direction .8m/s is in.

[Anonymous No.9329618]

>>9329606
Well, you can pluck a taut string, watch it vibrate, hear a tone, and conjecture that the vibration of the string is passed to your eardrum via the air, and your brain is interpreting the vibration of your eardrum as a tone.
then you can test it by placing an airtight gap or vacuum between your ear and the string.

[Anonymous No.9329621]

>>9329614
the two locations give the direction.

[Anonymous No.9329628]

If evolution is real then how come people with small penises exist? Why didnt large penises become the norm?

[Anonymous No.9329633]

Why can they not solve problem of chirality in origin of life?

[Anonymous No.9329636]

>>9329621
>>9329595
then you have to find the acceleration component in the direction of the velocity and in the direction perpendicular to it, then use the distance equation to find the amount of time it will take the object to reach that point, then use the time aquired from that, along with the acceleration to find the final velocity.

[Anonymous No.9329638]

>>9329628
Humans have enormous penises compared other great apes. Like, ridiculous big.

[Anonymous No.9329639]

>>9329638
doesnt explain why kevin chen has a 3ich penor and tribe leader mboko bdoko has a 7ich shlong
What could have possibly lead to genital size variation among different demographics?

[Anonymous No.9329641]

>>9329639
A more interesting question is how effective your racism will be as a sexual deterrent in a modern connected society.

[Anonymous No.9329642]

When does one use a z vs. t distribution for calculating confidence intervals and predictions of future intervals?

Textbook I have says that the former is for when the variance (o^2) is known and the latter for when o^2 is unknown, but all of my homework problems give the standard deviation which is just o (sqrt of o^2).

Am I missing something?

[Anonymous No.9329644]

>>9329641
Nice bait, you wont be derailing this discussion so easily

[Anonymous No.9329649]

>>9329628
because a penises length doesnt have enough to do with pregnancy rates for lengths to increase naturally. That and women dont tend to pick men purely based on their penis size.

[Anonymous No.9329658]

>>9329642
Use t-tests when n is small and σ2 is unknown. If n>30 and σ2 is known, normal is correct (the CLT carries the day).

[Anonymous No.9329663]

>>9329628
penis size doesn't affect pregnancy, unless it kills her, which is why we dont have hypercocks

[Anonymous No.9329669]

>>9329639
all studies where doctors measure penis size have the races about equal in the penis size department.

[Anonymous No.9329678]

>>9329658
Thank you, kind anon!

[Anonymous No.9329685]

So apparently pic related is true. I tried out the functions f(x) = [sqrt(x)]^4, and g(x) = -x^(-1/3). Both have positive derivatives as far as I know, but f(g(x)) seems to yield x^(-2/3), which is decreasing for positive values of x. Why am I getting an impossible answer? What the heck am I doing wrong?

[Anonymous No.9329699]

>>9329685
the claim is only true when the composite is a well-defined real-valued function. f(x) is defined for x>=0 and the range of g(x) is y<0

[Anonymous No.9329708]

>>9329699
So... you're saying the main problem is the potential zero in the denominator?

[Anonymous No.9329712]

>>9329708
I'm saying g(x) is always negative, so you can't plug it into f(x) since sqrt(x) requires x>=0

[Anonymous No.9329714]

>>9329712
Ahh, okay. Thanks!

[Anonymous No.9329727]

>>9329618
The string vibrates as a transverse wave up and down but the sound wave is a longitudinal 'pressure wave' of air compressing and decompressing like a slinky. Then it hits your eardrum which then vibrates up and down like a trampoline type of wave. Do all of these different waves have the same frequency, amplitude, and other properties? How can we know?

[Anonymous No.9329740]

>>9329727
Can the amplitude of a sound wave even be directly compared to the trampoline wave? Obviously they'd be correlated, but wouldn't you at least need to use different units?

[Anonymous No.9329834]

>>9325135
they use it at my uni, i think it's pretty good
also there is only one copy of rudin

[Anonymous No.9330009]

>>9329405

Nise

http://4chan-science.wikia.com/wiki/Electrical_and_Electronics_Engineering#Control_Theory

[Anonymous No.9330021]

>>9329443
>Apparently all reals have a unique infinite decimal expansion

No, all real numbers have a unique infinite decimal expansion except ones that end in all zero which are paired in an equivalence relation with the last nonzero number decremented and padded with repeating 9s.

https://en.wikipedia.org/wiki/0.999...#Infinite_decimal_representation

[Anonymous No.9330027]

>>9330021
>all real numbers have a unique infinite decimal expansion except ones that end in all zero
any proof that those are the only exceptions?

[Anonymous No.9330036]

>>9330027
https://arxiv.org/abs/1101.1800
Foundations of Real Numbers by Claude W Burrill

[Anonymous No.9330040]

>>9328930
--lua

function getcash(amount)
local fifties = 0
local twenties = 0
while amount < 20 do
if amount%50==0 then -- (mod)
fifites = fifties + amount/50
amount = 0
else
amount = amount - 20
twenties = twenties + 1
end
end
return fifties,twenties,amount
end
print(getcash(130)) -- displays fifties, twenties, then leftover cash.

[Anonymous No.9330044]

>>9330040
>no whitespace on 4chan

i want to die

https://pastebin.com/c7AGHdTP

[Anonymous No.9330084]

>>9330036
thanks man. i guess lemma 2.12 can be seen as equivalent to my question

[Anonymous No.9330101]

>>9330027
you can prove anything with bad assumptions

[Anonymous No.9330103]

>>9330044
>no whitespace on 4chan
step up your autism senpai

[math] \texttt{function getcash(amount)} \\
~~~~~\texttt{local fifties = 0} \\
~~~~~\texttt{local twenties = 0} \\
~~~~~\texttt{while amount < 20 do}\\
~~~~~~~~~~\texttt{if amount%50==0 then -- (mod)}\\
~~~~~~~~~~~~~~~\texttt{fifites = fifties + amount/50} \\
~~~~~~~~~~~~~~~\texttt{amount = 0}\\
~~~~~~~~~~\texttt{else}\\
~~~~~~~~~~~~~~~\texttt{amount = amount - 20}\\
~~~~~~~~~~~~~~~\texttt{twenties = twenties + 1}\\
~~~~~~~~~~\texttt{end}\\
~~~~~\texttt{end}\\
~~~~~\texttt{return fifties,twenties,amount}\\
\texttt{end}\\
\texttt{print(getcash(130)) -- displays fifties, twenties, then leftover cash.} [/math]

[Anonymous No.9330152]

>>9325453
One final bump
>>9330040
getcash(n), for n>550 and 20|n-500, does not meet the challenge conditions of 10 fifties and 10 twenties.

[Anonymous No.9330249]

>>9330103
r u a wizard?
[eqn]
\begin{verbatim}
Does
this
work
\end{verbatim}
[/eqn]

[Anonymous No.9330254]

>>9328930
I'm on a windows computer, so I had to learn powershell to solve this. I believe this should work fine:
[eqn]
$x = 130; $K50 = $K20 = 10; $c50 = $c20 = 0
while($x -ge 50 -and $x % 20 -ne 0 -and $K50 -gt 0){
$x = $x - 50
$c50 += 1
$K50 -= 1
}
while($x -ge 100 -and $K50 -gt 1){
$x = $x - 100
$c50 += 2
$K50 -= 2
}
if($x % 20 -ne 0 -or $x / 20 -gt $K20){
echo "No solution"
}
else{
$c20 = $x / 20
echo "Num 20: " $c20
echo "Num 50: " $c50
}

[/eqn]
$x is the sum client wants.

[Anonymous No.9330256]

>>9330249

[Anonymous No.9330257]

>>9330254
Apparently I can't format code either.

$x = 130; $K50 = $K20 = 10; $c50 = $c20 = 0
while($x -ge 50 -and $x % 20 -ne 0 -and $K50 -gt 0){
$x = $x - 50
$c50 += 1
$K50 -= 1
}
while($x -ge 100 -and $K50 -gt 1){
$x = $x - 100
$c50 += 2
$K50 -= 2
}
if($x % 20 -ne 0 -or $x / 20 -gt $K20){
echo "No solution"
}
else{
$c20 = $x / 20
echo "Num 20: " $c20
echo "Num 50: " $c50
}

[Anonymous No.9330269]

>>9330256
Oh, wow. I didn't even know there was such a feature. The latex looks really cluttered though. /sci/ could use a code-blocks like /g/.

[Anonymous No.9330275]

>>9328930
>he never heard about greedy algorithms
Been in IT for 20 years, forever ignorant

[Anonymous No.9330298]

>If you don't finish the bid, the boss ______ give you a raise.
Should we use "won't" or "isn't going to"?
Also:
>You ______ tell my secret to anyone. Do you promise?
"Can't" or "musn't"?

[Anonymous No.9330310]

>>9330298
Why is this on /sci/ - Science and Math?
As a US English speaker, I would choose "won't" and "must not."

[Anonymous No.9330313]

>>9330298
What's the point of that exercise when all options are correct? If it were about scientific writing, the actual correct answers would be "will not" and "must not".

[Anonymous No.9330314]

>>9330298
"Won't", then "mustn't". For "isn't going to" to be correct, the part preceding it should say "If you aren't going to finish the bid..."
"Can't" carries the implication that an action is physically impossible. They *can* tell your secret to anyone, but you really don't want them to.

[Anonymous No.9330315]

>>9330310
It's, uh, linguistic analysis.

[Anonymous No.9330343]

>>9325885
Point of a moment generating function (big surprise) is to generate moments and to prove certain results.

Since [math] \frac{d^k}{dt^k}e^{tx}|_{t=0}=x^k [/math] we can find E(X) and such for trickier random variables.

[math] \frac{d^k}{dt^k}\sum{}_{\chi} [e^{xt}P_X(x)]|_{t=0} [/math] or [math] \frac{d^k}{dt^k} \int_{\chi}^{} e^{xt}f_X(x)dx |_{t=0} [/math] in the continuous sense gives us [math] E(X^k) [/math] . So know t for these does not refer to time nor anything specific.

In the case of the Poisson process t in P(N(t)=n) DOES refer to time, since it's referring to a number, the rate of occurrences from time 0 to t. In the problem above, it refers to a homogeneous pp with single parameter lambda. So use N(1) for the formula your posted, for [math] E_N(e^{tn}) [/math] X, N, makes no difference.

[Anonymous No.9330365]

>>9325085
(1+8) in brackets do it first to get 9
(9)3+1 = (9)4 = 9x4
the answer is 36

[Anonymous No.9330449]

i have no idea how to solve this. pls help

An electron and a positron are initially 3x10^-15m from each other and moving directly toward each other. At this point, the total kinetic energy of the two particle system is 1.8x10^-13j (that is, the kinetic energy of each particle is half of this). When they reach a distance of 1x10^-15m apart, what is the total kinetic energy of the system?

[Anonymous No.9330460]

Given that you have a function
[math] f(t)=\int_{a}^{b} g(t,x) dx [/math] ; a, b in the extended reals.
which are exactly the necessary and sufficient conditions for
[math] f'(t) = \int_{a}^{b} \frac{\partial g}{\partial t}(t,x) dx [/math]
to hold?

[Anonymous No.9330469]

An object oscillates on a spring. When it's displacement from equilibrium is 3.14 cm, the object has a speed of 61.5 cm/s. When it is at 7.01 cm from equilibrium, it's speed is 45.0 cm/s. If the mass of the oscillator is 1.00 kg, what is the maximum speed of the object as it oscillates?

How would I go about this? Any hint appreciated.

[Anonymous No.9330504]

Is there anyway to solve the integral on the bottom line?

[Anonymous No.9330550]

>>9325077
I understand the binary system but I don’t get how you write sentences.

Becuase if you use the space between numbers to represent a new letter, you can’t use it also to represent a new word.

[Anonymous No.9330555]

>>9325918
That's really fucking vague anon. Do you really want help with it?

[Anonymous No.9330557]

>>9325077
so me and a friend of mine hailed a van with other passengers in the back going to the office. We sat in the front besides a qt brunette with a tight skirt and a green blouse. As soon as we handed out the fare, the men at back started saying "just because you look poor"

what did they mean by this? and why do people do this?

I assume it's because
you have something I don't REEEE

[Anonymous No.9330561]

>>9330557
hoping a psyanon could help explain

[Anonymous No.9330563]

>>9326076
cost probably. fast doors would be a much higher expense to a given store for a benefit they might not value.

[Anonymous No.9330571]

>>9326095
People are saying "trickery" is mostly the content and they're not wrong. Here's the breakdown:

>Separation of Variables
>Bernoulli equations
>Solutions by substitution/reduction of order
>Solutions by integrating factor
>Homogeneous linear equations of nth order
>Variation of Parameters
>Cauchy-Euler equations
>Method of undetermined coefficients
>Probably some modeling applications, but not always
>Solutions by series
>Solutions by Laplace transforms
>Systems by Eigenvaleus and Eigenvectors

Know your calc II material, specifically integration techniques, power series, and testing series for convergence/divergence.

This class is algebra wired on fucking meth with a small calculus cameo.

[Anonymous No.9330573]

>>9326076
either cost or safety. How fast do you really want to slide large pieces of glass and metal back and forth? how much are you willing to pay some deadbeat parent after they let their kid get bashed by the door when they sit in the track for the sliding door? plus low impulse doors will last longer and will require less maintenance for their lifetime.

[Anonymous No.9330591]

>>9330571
If it's an ODE for math then it's quite dufferent. Peano & picard theorem, linear systems, qualitiative study & poincare bendixson

[Anonymous No.9330594]

>>9330550
Binary is only a way of representing numbers. Without encoding, there's no way to derive a meaning from the numbers.
The binary string:
001100100010000001101101011001010110111000100000011010010110111000100000011100100110010101100100
Is interpreted by a computer with the expectation that it is under a certain encoding.
If the computer expects ASCII, it will consider each group of eight bits to be one character.
00110010 00100000 01101101 01100101 01101110 00100000 01101001 01101110 00100000 01110010 01100101 01100100
Now, it will show the character associated with each group of eight.
2 men in red
Note that the space between groups of eight isn't a 1 or 0. I just put it there to make the groups of eight easier to distinguish-- the computer doesn't need to do this.
The space between words is a character of its own, specifically the one encoded as 00100000.
Hope this helps.

[Anonymous No.9330607]

>>9330557
They were jackasses showing off in front of a hot girl. Probably about as deep as that goes.

[Anonymous No.9330612]

What's the deal with allele genes? During Mendel's experiments there were two allele genes for each characteristic, one organism being homozygous for the dominant genes, if I remember correctly. The two allele genes were in two different homologous chromosomes of the two organisms (one pair for each characteristic) so that's why Mendel came up with the analogy of 9:3:3:1.

If so, what would happen if the allele genes weren't in two different homologous chromosomes, but in one?

For example, normally in independent chromosomes there would be 4 of them, one carrying a dominant K gene, one carrying a recessive k (forming a pair) and the others similarily with a dominant P and p gene respectively.

If they were conjoined (two dominant genes in one homologous chromosome and two recessive ones in another) there would be less gametes during meiosis and therefore less combinations resulting in a different analogy than before, correct?

I am aware to how contrived and confusing this sounds but I am trying to translate all these terms from my textbook which is hard to do so I had to google some terminologies.

[Anonymous No.9330614]

>>9326879
what level? I'm not an anglophone so I'm not aware of these terminologies.

[Anonymous No.9330633]

>>9330594

>Hope this helps

It did, thanks

[Anonymous No.9330655]

Is chemical engineering useful in R&D, or should I stick with materials science.
I heard chemistry undergrads are treated like lab monkeys.

[Anonymous No.9330668]

if
f(2x)=4x+2
then
f(x)=2x+1
??

[Anonymous No.9330676]

>>9330668
Yes

[Anonymous No.9330678]

>>9330668
No.

[Anonymous No.9330681]

>>9330668
No retard
f(x) = 2x + 2

[Anonymous No.9330682]

>>9330676
>>9330678
why? REEEE

[Anonymous No.9330687]

>>9330681
how did you get that?

[Anonymous No.9330689]

>>9330687
It's trivial and left as an exercise for the reader

[Anonymous No.9330693]

>>9330687
>how did you get that?
Substitute y=2x

[Anonymous No.9330694]

>>9330689
REEE*(10^100)

[Anonymous No.9330695]

>>9330693
thanks you bro, i had the idea but i was never thaught this

[Anonymous No.9330699]

>>9330693
wait how exactly do you do that?

[Anonymous No.9330829]

>>9327268
1+1=11 base 1

[Anonymous No.9330833]

Could someone help explain how to find the domain, co-domain, and image of some function, for example:

f : [math]\mathbb{N} \to \mathbb{R}[/math] where f(x) = 1.

Thank you!

[Anonymous No.9330839]

>>9330833
domain = N
codomain = R
image = {1}

[Anonymous No.9330844]

Someone tell me what's wrong with my beginner's python script? Need it for lab report due in morning.
when I choose to plot out cumulative_ratios the graph is correct, but for some reason the script doesn't plot it out as approx_integration against the exact value

[Anonymous No.9330845]

>>9330839
That seems almost too easy, and if the function was something like:

f : [math]\mathbb{N} \to \mathbb{Q}[/math] where f(x) = x + 1,

the domain would be N, the co-domain Q, and the image would be...?

[Anonymous No.9330849]

Can you prove the world isn't flat?

[Anonymous No.9330852]

>>9330845
if y is in the image then y=x+1 for some x in N, and so y is in N. every natural number n except for 1 can be written as n=x+1 for some other natural number x, so the image is the set of natural numbers except for 1.

[Anonymous No.9330863]

>>9330852
Oh that makes complete sense, is there some formal notation to define the image in this case or would it just be y = x + 1?

[Anonymous No.9330869]

>>9330863
>, is there some formal notation to define the image in this case or would it just be y = x + 1?
[math] \mathbb{N}\backslash \{1\} [/math]

[Anonymous No.9330873]

>>9328925
Can ANYONE answer this definitively?

[Anonymous No.9330875]

>>9329024
>Why should I believe that?
So what's your personal theory on it, Einstein?

[Anonymous No.9330879]

>>9330869
And the purpose of the \ is essentially [math]\mathbb{N}[/math] sans 1?

So for the previous example the domain would be [math]\mathbb{N}[/math], the co-domain [math]\mathbb{Q}[/math], and the image [math]\mathbb{N}[/math] / 1?

[Anonymous No.9330885]

>>9330879
>And the purpose of the \ is essentially N sans 1?
Yes (http://mathworld.wolfram.com/SetDifference.html))

>So for the previous example the domain would be N, the co-domain Q, and the image N / 1?
yes but N\1

[Anonymous No.9330890]

Why would females select for smaller penis size in some areas of the world? Would this yield a better chance for survival in war/rape prone areas like asia?

[Anonymous No.9330894]

>>9330885
Oh I had no idea it was supposed to represent difference! So the image/function is a subset of the domain that you can do set operations on?

[Anonymous No.9330912]

>>9330890
it's linked to neanderthal dna and intelligence

[Anonymous No.9330915]

>>9330844
>np.cumsum(inside)
L-lewd

[Anonymous No.9330916]

>>9330915
kek
HELP

[Anonymous No.9330918]

>>9330915
you know some nerd named it cumsum just to be funny

[Anonymous No.9330927]

>>9330894
>So the image/function is a subset of the domain that you can do set operations on?
I'm not sure what you're trying to ask here

[Anonymous No.9330937]

>>9330927
Sorry, I'll try to be more clear.

I'm asking if the image of the function is a subset of the domain with some defined parameters, like x + 1?

So the image would be the subset of the domain where f(x) is x + 1?

[Anonymous No.9330950]

>>9330937
>I'm asking if the image of the function is a subset of the domain with some defined parameters, like x + 1?
In general no, consider the function N -> Q defined by x -> x/2 (elements in the image like 1/2 and 3/2 aren't in N so the image isn't a subset of the domain)

[Anonymous No.9330977]

>>9330950
Okay, that makes complete sense, thanks a lot!

One last thing, how would I go about defining an image with some power, for instance:

h : [math]\mathbb{Z} \to \mathbb{R}[/math] where x^2?

[Anonymous No.9330978]

how would someone apply Monte Carlo method to integration in multiple dimensions? I imagine it's something like plotting random points in the given dimension and calculating the ratio located below the hyperplane?

[Anonymous No.9330981]

How do I solve a problem where I need to know the number of combinations possible when two items cannot be next to each other (for example, you have five differently colored beads that can rotate freely around a bracelet, so how many bracelets can you make this way if the blue and green bead can't be next to each other?)

[Anonymous No.9330982]

>>9330981
to clarify, in my example the bracelet is already tied so the order they were placed on the string is fixed.

[Anonymous No.9330988]

>>9330977
image(h)={n^2 | n in Z}

[Anonymous No.9330989]

>>9330988
Okay, so it's just some instance of n^2 where n is some integer?

[Anonymous No.9331003]

>>9328925
no. probability works best with fractions. even if they arent explicitly needed, we'd still use them without the imperial system just to make things easy.

[Anonymous No.9331011]

>>9330849

[Anonymous No.9331014]

>>9330612
>If so, what would happen if the allele genes weren't in two different homologous chromosomes, but in one?
the ratio would reflect the crossing over probabilities and chromosomal distances of the loci

[Anonymous No.9331028]

How do you normalise a vector?
My lecturer gave it as:
1/||x|| * x

but I've seen it elsewhere simply as:
1/||x||

[Anonymous No.9331055]

How do I solve this equation for x?
[math]16^{2^{x}} = 2^{16^{x}}[/math]
Even though it seems simple I'm struggling, my intuitive answer was 0 since then both numbers would be raised to 0, but turns out it's not how powers work

[Anonymous No.9331059]

>>9331028
>but I've seen it elsewhere simply as:
>1/||x||
that's not a vector

[Anonymous No.9331062]

>>9331055
16= 2^4

[Anonymous No.9331070]

>>9331062
I know, I tried this but then to my brainlet logic
[math]2^{4^{2^{x}}} = 2^{16^{x}}[\math]
so then
[math]2^{16^{x}} = 2^{16^{x}}[\math]
which has infinite solutions, so something must be wrong

[Anonymous No.9331071]

>>9331070
[math]2^{4^{2^{x}}} = 2^{16^{x}}[/math]
[math]2^{16^{x}} = 2^{16^{x}}[/math]
please be patient i have autism

[Anonymous No.9331088]

>>9331070
>>9331071
[math] (a^b)^c = a^{bc} \text{, not } a^{b^c} [/math]

[math] 16^{2^x} = 2^{16^x} \\ \iff (2^4)^{2^x} = 2^{16^x} \\ \iff 2^{4 \cdot 2^x} =2^{16^x} \\ \iff 4 \cdot 2^x = 16^x \\ \iff 2^2 \cdot 2^x = (2^4)^x \\ \iff 2^{x+2} = 2^{4x} \\ \iff x+2 = 4x \\ \iff x=\frac{2}{3} [/math]

[Anonymous No.9331112]

>>9331088
thank you anon :3

[Anonymous No.9331137]

>>9331112
no problem friend

[Anonymous No.9331329]

Is there a technique in linear algebra that allows me to solve 5x5 linear systems with a calculator that only solves 3x3 matrices? Like, doing it multiple times to get part of the solutions instead of doing it all at once?

[Anonymous No.9331352]

>>9331329
Well, if you can write R^5 as a direct sum of subspaces which are invariant under A, then you can solve the system on those subspaces and combine the results.
Essentially, if you can write A into a block diagonal form diag(A1,A2,...,An), then Ax=b is equivalent to A1x1=b1 and A2x2=b2 and ... and Anxn=bn.

[Anonymous No.9331375]

>>9331055
x=2/3

[Anonymous No.9331381]

>>9331375>>9331088
kek havent seen this

[Anonymous No.9331386]

>>9331352
I think I understand. But is there an algorithm that will allow me to solve for any case?

[Anonymous No.9331399]

>>9331386
I don't know.

[Anonymous No.9331443]

>>9325077

So, it is posible to calculate the minimum of how many people voted based a percentage?

example the percentages are 50-50, so the min must be 2 people, 1 voted A 1 voted B

but what for something like 40-20-20-20?

[Anonymous No.9331502]

>>9331329
You can express the inverse of a matrix as a combination of expressions involving submatrices. See e.g.
en.wikipedia.org/wiki/Invertible_matrix#Blockwise_inversion

But that may be more trouble than just solving by hand.

[Anonymous No.9331514]

>>9331443
You'd need to know the error bounds. Percentages are almost always approximations; a fraction can't be expressed exactly as a percentage unless the fraction's denominator has a prime factorisation of the form 2^m*5^n.

If you're given the proportions as fractions in their lowest form, then the minimum number is the least common multiple of the denominators.

[Anonymous No.9332309]

>>9331502
>>9331352
>>9331329
Okay, so I just made this up:

Let [math] N [/math] be a [math] [2n \times 2n] [/math] invertible matrix, in the form:
[eqn] N = \begin{bmatrix} A && B \\ C && D \end{bmatrix} [/eqn], where each block matrix [math] A, B, C, D [/math] are also invertible. The linear system [math] N\omega=b [/math] can then be transformed into [eqn] \begin{bmatrix} I && 0 \\ 0 && I \end{bmatrix} \, \begin{pmatrix}u \\ v \end{pmatrix} = \begin{pmatrix} \left ( D^{-1} C - B^{-1}A\right ) ^{-1} \left ( D^{-1} y - B^{-1}x \right ) \\ \left ( A^{-1} B - C^{-1} D \right )^{-1} \left ( A^{-1} x - C^{-1} y \right ) \end{pmatrix} [/eqn], where [eqn] \begin{pmatrix}x\\y\end{pmatrix} = \omega [/eqn] are subspaces of [math]\omega[/math].

Pic related, precision to 1 decimal place. Where's my field medal?

[Anonymous No.9332318]

>>9332309
I meant [eqn]\begin{pmatrix}x\\y\end{pmatrix} = b [/eqn]
Doesn't work for 5x5, matrices, only even dimensional ones, unfortunately. But it can reduce a 6x6 system into a series of 3x3 operations that I can do in my calculator. Maybe I can introduce a dummy variable into a 5x5 to make it into a 6 by 6 so I can use this.

[Anonymous No.9332347]

Anyone here familiar with functions? I'm not entirely sure on how to calculate a function and then find the resulting domain and codomain of the resulting function, for example:

Let f : {1, 2, 3} [math]\to[/math] {a, b, c}, g : {a, b, c} [math]\to[/math] {10, 20, 30, 50}.

What would g of f be in this instance?

[Anonymous No.9332646]

>>9332347
Do you even know what [math] f: \{1,2,3\} \to \{a,b,c\} [/math] means?