/sci/ - Science & Math

Alternate form of [math]\sqrt{x}[/math] is [math]{x}^{1/2}[/math].
What is the alternate form of [math]\sqrt{x}^\sqrt{x}[/math]?

>>9199464
x raised to the one half, raised to the x, raised to the one half

>>9199488
What happens if that goes to infinity?

>>9199491
I'm not doing your homework for you

Put it in symbolab and take the limit as x approaches infinity

>>9199502
No, I meant as more and more exponents piling up. I'm trying to wrap my head around it.

>>9199510
Graph the function then , dude. Fx is getting bigger. Square root doesn't reduce x that much. Sqrt 100 raised to sqrt 100 Is just 10^10, etc

Are you in 10th grade?

>>9199491
>infinity
No such thing.

>>9199462
so what do you do when you get a sour phd student as a lab supervisor

how the FUCK do I code vhdl, I'm going insane trying to figure out how to make an ASU in it.

>>9199605
prepare myself to finish with a C in the lab component of the course.

Who the fuck is such a numale faggot that cries shit in sex other than some grunt lmao.

>>9199834
it's clear you have never watched hentai. Leave this board, and never come back.

>>9199462
What should I start doing as an undergrad if I eventually want to do a PhD?

>>9200037
>if I eventually want to do a PhD?
Since I don't know your major some general advice:
1) Get good grades and try to learn beyond your course material with self study. Remember that "good grades" means 3.5-7 in major, >3.0 cumulative, you don't need a 4.0 to get into a good program, but it helps.
2) Form relationships (positive) with your professors.
3) Do some kind of internship or research experience every summer. If you don't do this, you need a 4.0 GPA.
4) Figure out what getting a PhD entails. Figure out what PhDs in your field actually do. Figure out what you want in life (in terms of life style and quality, not whether or not you want to "be a professor" or "be a scientist" or "be the next [your sciencefu]"). Make sure that getting a PhD is how you want to go about attaining that life you want. Be aware that there are other options, but that you're choosing to do a PhD because it's what you want.

(btw, there's a name for people who don't do (4). It's "master of science.")

Do people always share more of an expressed phenotype with their siblings than they do anyone else on earth?

>>9200122
That's pretty subjective

My brother started reading this lately and keeps talking to me about it. What can I tell or link him to refute what the book says, assuming he will even read it?

>>9200130
Why? Don't I share more non-dormant genes with my brother and sister than with anyone else? And If geneotype determines phenotype, then it should stand to reason that ours is also most similar? Sorry if I sound retarded

If the multiverse theory is correct, then is there a universe where no one has ever flipped a quarter that's landed on tails?

>>9200155
It's called the kinoverse.

https://www.youtube.com/watch?v=NbInZ5oJ0bc

>>9199462
>pic

So do Christcucks shout of "baby Jesus", or "Virgin Mary", or "Yahweh" when they cum?

>>9200183
watching Gary Oldman say heads over and over is a tough thing to do

>>9200227
Wow, you have issues dude.

I'm trying to extend the euclidean algorithm to find

d = as + bt where d = gcd(a,b)

I've applied the Euclidean Algorithm:

a = 270, b= 192

270 = 192 * 1 + 78
192 = 78 * 2 + 36
78 = 36 * 2 + 6
36 = 6 * 6 + 0

r = 0 so we terminate and the gcd = 6.

Extending the Euclidean Algorithm

6 = 78 - 36 * 2
= 78 -(192 - 78 * 2) * 2 //Expressing 36 from step 2 above.

I have to simplify and then express 78 from step 1 but everytime I do it, my final answer does not equate to 6.

Can anybody help me here?

>>9200155
multiverse =/= many-worlds

>>9200309
>Can anybody help me here?
we can't point out what you did wrong if you don't show your work

>>9200309
>>9200325

Apologies.

This is where I go from there:

= 3 * 78 + (-2) * 192 //the step I fuck up in, when trying to simplify
= 3(270 - 192 * 1) + (-2)192
= 3 * 270 + (-3)192

>>9200336
= 78 -(192 - 78 * 2) * 2
= 78 + (78 * 2 - 192) * 2

>>9200344
I must have a fundamental gap in my algebraic knowledge. I just don't make those natural jumps.

I can rewrite what you gave me as

= 78 + 2(78 * 2 - 192)
= 5(78) - 2(192)

Does that mean s = 5 and t = -2

This doesn't satisfy d = as + bt
As a and b are 270 and 192

So I would try and express 5(78) in terms of 270.

= 5(270 - 192 * 1) - 2(192)
And I'm lost from here.

>>9200373
>= 5(270 - 192 * 1) - 2(192)
>And I'm lost from here.
a(b-c)=ab-ac

>>9199464
[math]\sqrt x ^ \sqrt x=x^{x^{1 \over 2} \over 2}[/math]
Take a look into tetration

>>9200381
5(270) - 5(-192) - 2(192)
5(270) - 7(192)

Thank you so much. I'm definitely feeling like a moron at the moment.

Online calculator now tells me I've got the right co-efficients. To make sure I can do this in the future without just falling apart is it just practice and not overthinking it. Those basic arithmetic facts you applied I know of, they just don't jump off the page to me and I end up looking for other ways to do it and just ruining my process.

>>9200058
Thanks!

>>9200384
i'm not a chemist sorry

is cuckoldry really the intellectual's fetish?

>>9199462
brainlet here

There is a major such that there is a student in the class in every year of study with that major.

Let M(x, y) represent a major x that has students in all y class standings. The domain of x majors includes computer science and mathematics. The domain y includes all class standings freshman to senior.

∃x∀y M((x, y))

is this an acceptable expression

>>9200457
it has little to nothing to do with chemistry https://en.wikipedia.org/wiki/Tetration

>>9201034
>little
i'm not a chemist sorry

>>9201034
He's trolling you. I bet it's the same dude that says "No such thing" when someone mentions anything involving infinity.
Just ignore this kid until it's 9 PM and he has to go to bed.

>>9201039
But [math]\infty \notin \mathbb{R}[/math] so how can it exist

>>9200970
>∃x∀y M((x, y))
I think it's supposed to be ∃x(∀y(M(x,y))) but only if the graders is pedantic. Looks good otherwise.

I was curious about social structures, specifically familial ones but don't know what to read without getting things that are critical of social norms or that describe gender theory. I just want to know what exists, without a judgement of whether it's a good thing or something that needs to be changed. I don't know if this is psychology or sociology.
Also with a death in my family we were handed a pamphlet that pretty precisely described a timeline of decisions made by the person who was dying, and I don't know how to search for the psychology of death.

>>9201090
thank-you

How do I fucking concentrate to study when my mind is too busy having obsessive/intrussive thoughts?

For my QM class, the teacher gave us as reference books Quantum Mechanics and Advanced Quantum Mechanics, both writen by Schwabl. Does someone who did used them can give my his opinion on these two ?

Please explain, I just did a problem similar to this except it asked for the transform of sint * u(t-pi/2), where u(t-pi/2) is the unit step function. I ended up with se^(-pi/2)/(s^2 +1)

>>9201264
I'm retarded, here's the image.

Anyone ITT who is experienced with GNU/Linux and compiling source-code written in two different languages (C and C++ in this case)?

I need an answer relatively soon and don't want to take the time explaining it if no one can help lmao.

>>9201264
>>9201267
please respond

I recently read a short story that explained the acceleration of the expansion of the universe as the physical symptom of the timespace manifold being drawn into the event horizon of a temporal black hole. The writer argues that since time dilates as one approaches the event horizon of a physical black hole, physics must dilate as an object approaches the event horizon of a temporal black hole.

I know very little about time and astronomy, what are the problems with this theory?

What's a Perfectoid Space?

>>9201449
shape of your anus post-prolapse

>>9201449
>What's a Perfectoid Space?
https://mathoverflow.net/questions/65729/what-are-perfectoid-spaces
http://www.ams.org/notices/201409/rnoti-p1082.pdf

>>9200155
No. A coin toss is defined by many many things. Gravity, force, weather etc. And the many-worlds theory is a misnomer. What it should say is one-worlds. I don't doubt the existence of parallel worlds but given what we know of behavior and how things work, it's impossible for them to be any different from our own.

>>9199462
I recently read Scott Robertson's "How to Draw," and something threw me off.
Most of his drawings were in two point perspective.
I've been working at this for a few days, and I don't really see how to draft in true three point perspective.
I'd like to point out that three point perspective as it's presented now has the problem of being either angled up or down, and because of this it causes the picture plane to be distorted.
I've understood Robertson's perspective grid well enough to find the vanishing point for a line at any angle, but I have yet to find a way to simplify finding the vanishing points for a rotated cube.
Picture related.

>>9201573
Please respond.

>>9201573
just add another point of reference you brainlet

>>9201602
I'm not sure you understand the problem.

>>9199462
requesting the comparison of esteemed scientists (schrödinger etc) to "modern" scientists like bill nye and black sceince guy regarding philosophy

>>9201602
The purpose of this was to make a method artists could use.
If I start adding a coordinate system that means the person drafting has to calculate using numbers.
I'm looking for something that I can do using just a compass and a straightedge.
It is also useful to point out that there is already another point of reference, one is the camera, one is the line in question.
I was wondering how you can rotate said line to be perpendicular to the previous one.
Which would consist of several points of reference.
Unfortunately this does not help me solve my problem.
Please elaborate.

>>9201735
https://www.youtube.com/watch?v=EPBaHkj753I
shit face, literarlly 3 seconds of googling gets an answer

>>9201744
You have confirmed my suspicion that you do not understand what I am asking.
Most artists feel out vanishing points.
I'm trying to find an objective way to doing this WITHOUT feeling them out.
In the video the camera is pointed upwards, while the picture plane is still perpendicular to the ground.
What I am trying to do is to find the projection using a compass and a straightedge without a question of it's accuracy.
This requires the cube's view to not be relative to the camera, but to be rotated dependent on their own three lines.
The attached picture illustrates my point.
I want a view similar to something a 3d program would provide.
However, I would like to be able to do this by hand.

>>9201801

>>9201806
Simple problems such as looking up or down become increasingly difficult once the picture plane is horizontal, as the further you stray from the edges of your field of view, the more distorted the image becomes.
I would like control over this distortion, by having my center of vision be directly in the center of the diagram.

>study actuarial science in college, pass a few actuarial exams
>didn't do an internship while undergrad
How badly did I fuck myself? Does there exist a job anywhere in this field which will take a college graduate with no actuarial experience?

>>9199464
If sqrt(x) = x^(1/2) then it can be concluded
sqrt(x)^sqrt(x) = sqrt(x)^(x^(1/2)) thus
sqrt(x)^(x^(1/2)) = (x^(1/2))^(x^(1/2))

>>9200134
The wikipedia page for the book alone has like over a page of text concerning criticism of the book.

What are some resources to learn mental arithmetic? I never really studied it as a child and I'm slow/inaccurate as fuck. This is beginning to give me trouble, and I have a standardized test coming up requiring me to add three-digit numbers rapidly and accurately.

Are there any resources to hone your mental math skills?

>>9201927
9+17
26+37
114+230
you've got 20 seconds, no calculator, no writing of any kind.

>>9201821
I'm sorry if this has been confusing, were talking about something visual.
This is the distortion that I'm talking about.
If you can rotate objects by calculating the vanishing points.
You can then angle the camera.

>>9201952

>>9201940
26
63
344
wow im a math genius now thanks

>>9201957

>>9201960
the point is you literally just need practice the mental methods. speed comes in time.

>>9201960
oh and once you got the addition mastered try going
9*17
26*37
114*230
etc

>>9201960
There are asian kids that are so good at using an abacus that they can do complex math problems in milliseconds try that.

https://www.youtube.com/watch?v=3g63WR_PelY

>>9202044
AAAAAAAAAAAAAAAHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!!!

How does science rectify the ideas that time is not constant across the universe or that it might not exist but also that eventually the universe will experience a heat death?

>>9202056
It's inefficient to use your phonological loop to do math, so just learn the soroban, then practice for a few years until you can do problems without one.
Visually people can do this stuff in seconds.

>>9202078
remember, speed comes in time. if it takes your 10 minutes, then let that be a time with which you seek to improve on.

I get it algebraically, but is there a geometric or intuitive explanation for why n, (1/2)(n^2-1), and (1/2)(n^2+1) is a pythagorean triple? (n is odd)

>>9202434
proof: think

>>9202442
FUCK YOU

>>9202434
I get it algebraically, but is there a geometric or intuitive explanation for why 1+1=2?

>>9202457
cant get more intuitive and/or geometric than pic related

>>9202434
you can use to show that there are many points in the unit circle in Q^2

>>9202479
but thats just what other people tell me "2" is
not very intuitive at all
what if the all of the "1 thing"s are the same thing?

This is from the stable marriage problem.

A relationship is considered unstable if there is a roommate in each room who prefers eachother over their current roommates.

I know when ranking their preferences, every top preference must be different or there would be an arrangement that would be stable.

A B. C D
__________________________
1. B 1. C 1. D 1. D
2. 2. 2. 2.
3. 3. 3. 3.

>>9202434
I think this is the closest you're ever going to get to an answer to that question
https://www.youtube.com/watch?v=QJYmyhnaaek

I'm 26, have only a high school diploma and a desire to go to college to my name. I've been tested at a 125 IQ.

Realistically, what are my career prospects looking like? What's my professional ceiling?

What is the evolutionary practicality of idolism

>>9201039
>trolling
is this the new word for making a joke?

tetration sounds like titration

Struggling a bit with this coding theory problem.
For (a), I know that the answer is |Cn|=2^(n-1), but I'm not sure how to show it inductively.
For (b), I'm guessing the code is not MDS since for n=2, d=/=0 but again, not sure how to show this rigorously.
Not entirely sure how to approach (c).

>>9202758
for a)
|(Z_2)^n|=2^n
if u1...u_{n-1} is in C_{n-1} (inductively |C_{n-1}|=2^(n-2)) then u1...u_{n-1}0 is in C_n
if u1...u_{n-1} isnt in C_{n-1} (inductively 2^(n-1)-|C_n|=2^(n-2) such strings) then u_1...u_{n-1}1 is in C_n
so |C_n|=2^(n-2)+2^(n-2)=2^(n-1)

>>9202791
>(inductively 2^(n-1)-|C_n|=2^(n-2) such strings)
(inductively 2^(n-1)-|C_{n-1}|=2^(n-2) such strings)*

>>9202758
>>9202791
>>9202794
Is it that fucking hard to use tex?

>>9202831
>Is it that fucking hard to use tex?
hard no, unnecessary yes

>>9202832
>unnecessary
It's not though. Your garbage is unreadable.

>>9202868
>It's not though. Your garbage is unreadable.
if you have even a beginner's level of familiarity with latex it should be perfectly readable, you'll probably get more used to it within a few years

>>9202872
I didn't even bother trying to read it.

>>9202905
then how could it be unreadable?

>>9202910
It's impossible to read, why would one even try?

>>9202914
>It's impossible to read, why would one even try?
you can't know if it's impossible if you don't try

>>9202914
It really wasn't that hard to read, took me less than a minute to decipher mate

>>9202600
>26
You can do 2 things, and I am talking from experience.

1. Join any college for any degree, go into their Military program ROTC. Then go into the military as an officer. Then, in your free time, study FOR FREE the degree you want

2. Join enlisted (what I did) and not spend a dime in college. PICK A GOOD RATE, although, if you are as smart as you say, you should be fine.

t. scored 78 on ASVAB and currently a hospital corpsman in Singapore

>>9202946

thanks but I can't, a few days in the psych ward 5 years ago denies me entry into any military program immediately

>>9202924
I had another person try it.
>>9202930
That's actually a lot to waste on reading a post.

>>9202831
>>9203634
>just under 4 hours
thats a lot of time to waste on one post

What's the difference between an Automorphism and a Permutation?

>>9203902
automorphism has to preserve the algebraic structure, permutation doesn't

Is it possible to learn calculus in 2 weeks?

>>9203912
thanks anon!

a topology that is also closed under arbitrary intersection means that every open set is also closed, right?

Does it?

>>9203913
yes

>>9203935
it happens by pushing it through the formal definition iirc

>>9203935
Does [math] \frac{d}{dx} (cy) [/math] equal [math] c \frac{d}{dx} (y) [/math] .

If I get a small cut, it'll heal scab over in a day or so, then heal completely a bit slower than that.

If I have 100 cuts on my body simultaneously, will that haling process be any slower? If so, why?

>>9203922
Not necessarily. Consider any topology of R with only 1 non-trivial open set.

>>9199462
I feel for the CS meme, and want to know if it it's possible to do a Master's in Physics with Computational emphasis. I've got a few upper division math/physics courses such as Electromagnetism, Optics, and Optics Laboratory, Fourier Analysis, Introductory Analysis, and Stochastic Processes. Would I have a good shot?

>>9203978
Mathfag here, but I think it will heal slower.
From what I remember: there are cells which job is to "heal" and produce the fibers that close your wounds and there are cells that take care of inflammations and such (dunno if it's really cells that do that or if the wounds make your body produce anti inflammatory substances that help you though). If you have way too many wounds, your body won't be able to produce enough of these things to heal you, so it will definitely be slower (our bodies probably have a limit for how much they can produce of these things).
I mean, it's just logic. It's like you're demanding too much of something and such "something" can't produce as much as you need.
inb4 biofags bully me, I'm also interested in this question. Pls answer...

>>9203967
I'm thinking it does.

>>9204029
Hint: prove it using the limit definition for any constant c (it's very easy).

>>9203988
always forget to check cases like this, thanks

>>9201701

I'm having second thoughts about being in EE, I'm in second year right now, and while I don't mind circuits, these software classes are making my mind numb.

>>9201701
>>9204076
>modern scientists
You mean: science communicators.
You can't really compare Einstein, Bohr, Heisenberg, etc. with Tyson, Dawkins, etc., because their jobs are different. Yes, yes, most of them has worked/works as scientists, but they don't really spend the same amount of time and effort on it.
Those current "scientists" mentioned are mostly just science communicators, i.e. their job is to make science popular and get ordinary people into it. Their job is actually very important, since if you don't have support from the general public, you'll have a hard time getting support on doing science (you need the majority to think that whatever you research is important).

>>9204135
You're going to have to face it anywhere you go. That's just too useful for anyone to dismiss it.
My advice is: deal with it. Try to understand how important those classes are and do them as good as you can. The sooner you finish them, the sooner you'll be able to study only the subjects you like.

>>9200384
>tetration
Thank you, I'm the >>9199464 poster, not
>>9200457
This was exactly what I have been looking for.

What fuckin statistical test do I use to compare two time-dependent data sets. Dependent variable means no t-test

Does anyone have recommendations for books on network analysis? The one with the circuits and cut sets and stuff. We have a homework due soon and an exam down the road, and the professor's notes aren't just cutting it

>>9204184
Who were the great science communicators of a century ago? Two centuries ago? Serious question, I'm sure there were public lectures.

>>9204363
I really doubt that their main audience was the general people like those of today.

>>9204479
I don't know, most people today would rather watch sports or sitcoms than PBS anyway so I doubt it has changed all that much.

>>9204524
Well, at least today these "communicators" can reach way more people than they used to do back then, so it's good having them around, since the chance of people liking them and getting into real science is bigger (or at least respecting scientists and treating their jobs as something worth good for society).
I don't really pay attention to them, though.

What are prospective finance careers I can do with an undergraduate mathematics major.

I'm an estimator working at a light gauge steel manufacturing company, and the engineer is off work for the next week on annual leave, and we've received a question that I'd usually refer to the engineering department, however I can't.

I've been asked what the shear load to the steel beam would be in a certain area of the project (see image link)

The wind load for the project is 1.21kN/m2, and the 3.935m high studs are spaced at 400mm centres. Is this enough information to get a shear load per linear metre down to the steel beam below?

Any help will be appreciated.

I'm an estimator working at a light gauge steel manufacturing company, and the engineer is off work for the next week on annual leave, and we've received a question that I'd usually refer to the engineering department, however I can't.

I've been asked what the shear load to the steel beam would be in a certain area of the project (pic related)

The wind load for the project is 1.21kN/m2, and the 3.935m high studs are spaced at 400mm centres. Is this enough information to get a shear load per linear metre down to the steel beam below?

Any help will be appreciated.

>>9199462
if [math]\mathbb{R}^2 \cong \mathbb{C}[/math] what is the purpose of using complex numbers? i feel pretty dumb for asking this.

>>9204929
the isomorphism is only true depending on the structure you have in mind. it's true when thinking of them as sets or real vector spaces, but not as rings

https://math.stackexchange.com/questions/364044/difference-between-mathbb-c-and-mathbb-r2

https://math.stackexchange.com/questions/364044/difference-between-mathbb-c-and-mathbb-r2

>>9202434
I actually thought of something. Take a look at this.

Imagine the black square as a grid of dots, each side being [math]0.5(n^2-1)[/math] in length.
So there are [math](0.5(n^2-1))^2[/math] black dots in the image.
Suppose we want to turn this into a larger square grid of dots, [math]0.5(n^2+1)[/math] in side length.
Or, [math](0.5(n^2+1))^2[/math] dots in total.

So we add [math]0.5(n^2-1)[/math] red dots in a vertical line on the right side, and [math]0.5(n^2-1)[/math] red dots in a horizontal line along the bottom, then one more in the corner.
That's a total of [math]2(0.5(n^2-1))+1[/math] red dots, or simply [math]n^2[/math].

So for [math]a = n[/math], [math] b = 0.5(n^2-1)[/math], [math] c = 0.5(n^2+1)[/math],
we have the number of red dots plus the number of black dots equals the total number of dots in the grid. Or, [math]a^2 + b^2 = c^2[/math].

>>9204601
You srs? It's a huge field.
Take your actuary exams and get acquainted with financial stuff. Or apply to an MFE program, check em out at quantnet.com
Or you can not pay for grad school and just do a Statistics PhD which will land you a sweet job in finance.

>>9204929
I dont get your question at all. R^2 = 2dimensional real plane.
it's basically just saying you can describe a complex number by two real numbers (real and imaginary part)

>Study 2 hours of math every day
>Instantly clam up if any of the practice problems are remotely challenging
>Spend more time reading books or googling trying to figure out how to solve a problem rather than actually solve problems
How do I stop this?

>>9205354
ask for tips from your prof/tutor/other students to help you solve the problems.

also making study groups with other students, if only for the sake of seeing fresh ideas, might not be a bad idea (it incidentally also help reduce autism levels)

>>9200155
a coinflip isnt a quantum level stochastic event you nigger

>>9204929
Isomorphism only makes sense when you have fixed the structure you are talking about.

Currently working on this problem and struggling to write out the elements for the nontrivial codes. I've managed to determine that the 2 non-trivial codes are the principal ideals [x+1]R and [x^4+x^3+x^2+x+1]R, where R=Z2[x]/(x^5-1)Z2[x], but I'm not sure what the elements are. Would someone be able to give me some a hand with the [x+1]R elements.

>>9201874
There's no reason you can't get a job OR an internship in the meantime while looking for a job. A foot in the door is better than nothing.

Go to career fairs, and blast company sites w/resume, app. But remember talking to someone is much more effective in getting a position of any sort, rather than the latter.

>>9205354
Well, why do you wanna stop this? That's the best way to Actually learn stuff: exploring.
Also, you'll eventually do that much less than you do it now.

>>9205141
see
>>9205517
>>9204945

Can someone explain the logic behind proving this limit (part 2)? I don't understand how the instructor rewrote the equation, and why it proves anything.

I am not a flat earther, however if somoene asked me "Why do you believe the earth is round"? I wouldn't know what to say. What is the best, easiest way to explain the proof for a round earth? Particularly not using photos. Can you, for instance, easily prove the shape of the earth simply with a telescope or by observing the sky?

>>9199462
If I have a list with some calculable number of "0"s (between zero and two) and I know the number of unique permutations of this list, how can I use this to calculate the number of unique permutations that dont start with zero?

Any assistance with this problem would be greatly appreciated.

Let's say X is a random variable with an exponential distribution with mean = 1/2.

That has a probability density function of f(x) = 2*e^(-2x).

I thought the f(x) was supposed to represent the probability that the random variable X takes on the value x.

And I thought that the integral of the f(x) over all possible x was supposed to sum to 1.

So why does f(0) = 2?

>>9205878
>Can you, for instance, easily prove the shape of the earth simply with a telescope or by observing the sky?
You can, but that wouldn't confirm the round earth hypothesis.

>>9199488
Can someone explain why this is x^(1/2)^x^1/2 and not x^(1/2)(x)^(1/2)?

>>9205894
>I thought the f(x) was supposed to represent the probability that the random variable X takes on the value x.
That is for a discrete random variable.
For continuous random variables f(x) (small f) is the probability DENSITY function.
To get probabilities of a continuous random variable you use the Cummulative function.
The probability of a continuous variable getting a certain (single) value is 0.
Some continuous random variables don't even have probability density functions.

>>9205894
>>9205992
And to clarify:
>The probability of a continuous variable getting a certain (single) value is 0.
this doesn't mean that getting a single value is impossible. It means that it is improbable (it has probability 0).

For your case the probability of getting the value x=0 is easily seen from
[math] \int{0}{0} 2 e^{-2x} dx [/math]

Any geniuses on the board?

>>9205891
I think this will do:
[math] \sqrt{a} \in \mathbb{Q}(b^{\sqrt[3]{b}}) \implies \sqrt{a} = n + m \sqrt[3]{b}, n,m \in \mathbb{Q} [/math]
Now isolate the cube root of b:
[math] \sqrt[3]{b} = \frac{\sqrt{a} - n}{m} [/math]
Now raise both sides to the third power to get
[math] b= \frac{a^{1.5} + 3 a^{0.5} n^2 - 3an - n^3}{m^3} [/math]
Now, remembering that b,a,n and m are all rational numbers we can now isolate the powers of a and say that:
[math] a^{1.5} + 3 a^{0.5}n^2 = k, k \in \mathbb{Q} [/math]
Now multiply both sides by the square root of a to get:
[math] a^2 + 3an^2 = k \sqrt{a} \implies \sqrt{a} = \frac{a^3 + 3an^2}{k} \in \mathbb{Q} [/math]

Quick disclaimer:
I have gone through this proof like a cowboy. For a rigorous argument you would first want to argue why we can divide by m. Here the argument is simple: If m is 0 then immediately the square root of a is rational, so you want to assume that m is not equal to 0.

After that comes a trickier part, proving that you can divide by k (that k is non-zero). Here I am sure there are many ways to do this but the one I would choose is this: If k=0 then a must satisfy the polynomial [math] x^3 + 3n^2 x = 0 [/math] which will only have rational solutions. So again you say that you consider the case in which k is non-zero.

Hopefully that is good enough. By the way, what subject/class is this for?

Given a list which may contain duplicates, say, [math] \{a,b,c,d,a,b\} [/math], how can I calculate the number of unique permutations that don't start with a given value?

>>9206049
Cheers for that explanation mate, that makes a lot more sense than whatever I was trying to do. This question was for my algebra/number theory class (second semester of it).

>>9206072
You are welcome, I'll start Algebra 1 next semester so maybe I'll do well there.

>>9205868
pls someone, im dying here

>>9206049
Just a quick question, why is it that we can write [math]a^{1/2} = n +m*b^{1/3} [/math] for some rationals n and m?

This question is killing me

>>9206132
Because it is an element of [math] \mathbb{Q} ( \sqrt[3]{b} ) [/math] and I assume that:
[math] \mathbb{Q}( \sqrt[3]{b}) = \{a + b\sqrt[3]{b}, a,b \in \mathbb{Q} \} [/math] is what you mean by that.

>>9206132
>>9206169
Damn, there in the set I should have used x and y instead of a and b but you get the idea.

>>9206169
Oh I got you now, too easy

Struggling to make any progress on (a) and (c), any tips/tricks/hints would be appreciated.

What would be an example of a non smooth 3d curve?

Hi guys, I am studying for my discrete maths exam and there is this question on induction that I have no idea how to do.

(a) Use mathematical induction to prove that log2 n ≤ n for all integers n ≥ 1.

>>9206193
>>9206136
>>9206116
I would remember to rename the variable, since in F x is a new element of the field, I would call the second polynomial ring F[y] to avoid confusion.

maybe you can think of a possible root of your polynomial 1+y+y^2+y^3+y^4 (it has to involve x somehow since the polynomial didnt have a root in Z3)

or maybe you can take a step back and do an even easier problem. take the field Z2 and the polynomial f=1+x+x^2 in the ring Z2[x]
this is irreducible and the quotient F= Z2[x]/f is a field of four elements.

I would advise you to write down all elements of this field (maybe also calculate a bit in it) and try to find which of one these are roots of the polynomial g=1+y+y^2 in F[y]

>>9206475
[math]log_{2}n\leq n \Leftrightarrow 2^{log_{2}n}\leq 2^n[/math]

>>9205617
what am I supposed to see here?
I know C is a 2d real vector space and all real 2d vector spaces are isomorphic. whats your point?

>>9206778
when treated as groups wrt addition, they are isomorphic, similarly for vector spaces

when treated as rings, then we can define the second binary operation on R^2 by (a,b)(c,d) = (ac-bd,ad+bc), then they are isomorphic
but often the second binary operation on R^2 is not defined in this way, and they are not isomorphic

probably best explained by >>9204945

why are they telling me to square it if I'm just going to square root it at the end

>>9207144
Don't know m8, maths just weird like that. I don't understand what the fuck you are saying.

>>9207144
Pythagorean theorem

and [math] a^2+b^2 \neq (a+b)^2 [/math]

>>9207144
[math] \sqrt{a+b} \neq \sqrt{a} + \sqrt{b} [/math]

>>9206778
they are isomorphic only as vector spaces. but C is more than just a vector space, it comes equipped with a multiplication which turns C into a field and an algebra. a priori there's no such structure on R^2.

>>9207144
That way distance cannot be negative.

(sqrt(x))^2 is same as |x|

I'm trying to attempt a question for an assignment

Suppose that X ∼ Geometric(λ/n). Compute lim n→∞P(X ≤ n).

Do I have to use MGFs for this?

>>9206896
>>9207219
what part of my earlier replies made you think I didnt already know that?
I took algebra 2 (field / galois theory) a few years back

>>9201090
>>9200970
it should actually be

∃x∀y s.t. (x,y) ∈ M

>>9207324
so you understand that they are different ring structures
as a consequence, polynomials in C and R^2 are very different

britbong here, so idk how your courses work, but surely you must have done some polynomial rings before galois theory?

>>9207375
>polynomials in [math] \mathbb{R} ^2 [/math]

>>9207437
>
?
you can use elements of R^2 as coefficients, or do polynomials in 2 real variables, or both at the same time if you really want
https://en.wikipedia.org/wiki/Matrix_exponential
might interest you

Any help with this proof?

>>9207481
Trivial exercise.

By definition
[math] \forall \epsilon>0 \exists N: n \geq N \implies |a_n - L|< \epsilon [/math]

Now, let [math] \epsilon [/math] be a positive real number. Let [math] N [/math] be the natural number that satisfies [math] n \geq N \implies |a_n - L | < \epsilon [/math]. By the definition of your new sequence there will be some step k where this [math] a_n [/math] will be reached. QED. You can write out the details.

For this proof: if [math]xy>0[/math] then either [math]x>0[/math] and [math]y>0[/math] or [math]x<0[/math] and [math]y<0[/math], do I just go:

[math]xy=0 \implies xy \in P \subseteq \mathbb{R}[/math]

Case 1 : [math]x>0[/math] and [math]y>0[/math] . [math]x>0 \implies x\in P [/math], [math]y>0 \implies y \in P[/math], so [math]xy \in P[/math] as was required to show

Case 2 : [math]x<0[/math] and [math]y<0[/math]. [math]x<0 \implies -x\in P [/math], [math]y<0 \implies -y \in P[/math], so [math](-x)(-y) \in P \implies (-1)(-1)(x)(y) \in P \implies (1)(xy) \in P \implies xy \in P[/math] as was required to show.

Do I have to include x<0 and y>0 or x>0 and y<0, or can I QED it here? Note, the result that (-1)(-1)=1 was proven already in a former example so I can use it here.

>>9207527
Dude you did it backwards. You were supposed to prove that xy > 0 implies x>0 and y>0 or x<0 and y<0.

What you did was prove that x>0 and y>0 implies xy>0 and that x<0 and y<0 implies xy>0.

Fuck man I wish I could tell you I was not laughing right now. You are really bad at logic I'm sorry.

>>9207529
how then should the proof be done?

>>9207535
Assume [math] xy > 0 [/math].

First, if either x or y were 0 then xy = 0 so we can assume nether x or y is 0. This means we can divide by them.

Now, if x is not 0 then that means that x>0 or x<0. Lets suppose x>0. Then we can divide by x, preserving the inequality which yields y>0. As desired.

In the other case, x<0. If we now divide by x this flips the inequality, yielding y <0. As desired.

QED.

You had to prove that [math] Q \implies R [/math] but ended up proving [math] R \implies Q [/math].

>>9207541
ah yes, I see. however, we have not proved yet that for [math]x\in \mathbb{R}[/math], [math]\frac{0}{x} = 0 [/math]. Is there a more fundamental way to approach this without invoking division?

>>9207551
I did not use that in my argument though.

>>9207561
>Then we can divide by x, preserving the inequality
?

>>9207562
Ah I see what you mean now.
Then you can argue by contradiction. Suppose that x is positive and xy is positive. You want to prove that y is also positive so you go by contradiction:

If y was negative then xy would also be negative, which is a contradiction. Therefore y > 0.

>>9207566
right, I'll give this a crack then. Thanks.

>>9206060
Please respond :*(

>>9199834
You sound fun

How come /sci/ isn't as disgusted as /pol/ when it comes to liberal cucks trying to present a false sense of science in order to defend degenerate trannies and homos? This should make you furious that mentally ill deviants are even allowed to pursue a field which they clearly deny. What the fuck is wrong with you?

>>9206060
>>9207576
n1 of thing 1 , n2 of thing 2, ... , nk of thing k
N:=n1+n2+...+nk the number of all the things.
Say you don't wanna have thing i at the start (position 1 of the total N).
You have N-ni options there.
There you can put thing 1, or thing 2, ... , or thing i-1 , or thing i+1 , ... , or thing k.

If you put thing 1 then you have [math] \binom{N-1}{n_1 -1 , n_2 , n_3 , \ldots , n_k} [\math] ways to put the rest of the things.

If you put thing 2 then you have [math] \binom{N-1}{n_1 , n_2 -2 , n_3 , \ldots , n_k} [\math] ways to put the rest of the things.

etc. (except i)

Therefore it's

[eqn] \sum_{j=1 , j \neq i}^k \binom{N-1}{n_1 , \ldots , n_j -1 , \ldots , n_k} [/eqn]

>>9207630
pffffffff

>>9207625
Maybe they just have an interest in biology, what is wrong with that?

What is minimum amount of math required to understand Markov chains?

I'll reward a good answer with a doggo pic

How do I get the limit of the sequence

[math]1, \quad 1 + \cfrac{1}{2}, \quad 1 + \cfrac{1}{2 + \cfrac{1}{2}}, \quad 1 + \cfrac{1}{2 + \cfrac{1}{2 + \cfrac{1}{2}}}, \quad \dotsc[/math]

Ctrl+F "The number of line segments between closest pairs of dots in the triangle can be represented in terms of the number of dots or with a recurrence relation" in https://en.wikipedia.org/wiki/Triangular_number..

How did we derive this?

>>9208016
x = 1 + 1/(1+x)

>>9207858
Graphs
Baby proba

>>9208016

We have that x = 1 + 1/(1+x) implies x = sqrt(2).

Moreover, x --> 1 + 1/(1+x) is a contraction map on [1.1, 1.5], so starting at x = 3/2 (the 2nd term in your sequence) we can see that we get a convergent sequence, which necessarily converges to the fixed point.

>>9208035
>https://en.wikipedia.org/wiki/Triangular_number..

Connect the dots.

When you add the next row, you add n-1 horizontal segments, n-1 segments that look like /, and n-1 segments that look like \.

>>9208016
https://en.wikipedia.org/wiki/Continued_fraction

guys whats a good book on computational physics i need some advanced topics in monte carlo simulations

>>9204363
I know Faraday and Feynman both did 'science communication' type things. Can't think of people who weren't well respected scientists, maybe forgotten to time.

>>9207566
>Then you can argue by contradiction.
>can't tell the difference between a proof of a negation and "proof" by contradiction
Fuck off to >>>/r/eddit/

>>9207490
>N<=n
>letting small n be bigger than big N

If b=1 then how does [sqrt]b^3 =b

>>9208814

1^2 = 1 = 1^3

>>9205868
I'd just use polar coordinates.

Why is it that after integrating (with respect to x), a result of x^a + c can be turned into Ax^a?

>>9209117
I don't understand what you are trying to say. Can you rephrase?

>>9207625
>What the fuck is wrong with you?
Most people on /sci/ do not care. Even if you are a far right reactionary but study math certain degeneracy is less important then what you are studying.

>>9208016
First you notice that the sequence is [math] f^0 (1) , f^1 (1) , f^2(1), f^3(1) , \ldots [/math] where [math] f(x)=1+frac{1}{1+x} [math] .
Restrict that function on [math] D:= [1, + \infty ] [/math] .

Then you notice that [math] |f(x)-f(y)| < c |x-y| [/math] for all [math] x,y \in D [/math] ( [math] c \in [0,1) [/math] ). (the proof of this is trivial and is left as an excercise to the reader)
Now you can apply the Banach Fixed Point theorem which tells you that [math] f [/math] has a unique fixed point [math] a [/math] and it is found by [math] \lim_{n \to \infty} f^n (x) [/math] where [math] x [/math] is Any point of [math] D [/math] .

By solving [math] f(a)=a [/math] you find that the fixed point [math] a [/math] must be [math] \sqrt{2} [/math] .

And from the above, you have that [math] \lim_{n \to \infty} f^n (1) = \sqrt{2} [/math] .

How do I solve pic related?
I've been told that the substitution
[math] u = y(x)e^x [/math]
might be useful.
Any hints on where to begin?

>>9209192
>(the proof of this is trivial and is left as an excercise to the reader)
actually I am retarded
Just apply the mean value theorem for the interval [x,y] in D.
f'(ξ)=1/(1+ξ^2) is less than 1/2 when ξ>1.

>>9209211
actually nvm ξ depends on x,y

>>9209192
>(the proof of this is trivial and is left as an excercise to the reader)
[math] |f(x)-f(y)| = \frac{|x-y|}{|x+1| |y+1|} \leq \frac{1}{4} |x-y| [/math]

>>9209122
Suppose we have a/t = f'(t) / f(t). Integrate both sides to get a^t + c = f(t). But apparently, we could just as well say A * a^t . Why is this?

How to "get" what a martix determinant is? What is it's origin? How does one derive the formula for it?
I thought having some historical context on how it was invented would help but I can't really find anything like that.

>>9209289
How much do you know ? There are many ways to look at it

>>9209268
>But apparently, we could just as well say A * a^t
according to who?

>>9209307
HS math, just stated linear algebra

>>9209310
http://cuhs.co.uk/wp-content/uploads/2016/03/advpcm.pdf
Page 49.

Would it be correct to say that machine learning-based prediction algorithms are concerned not with the past and future, but only the present because of the law of large numbers?

>>9209320
a/t = R'(t)/R(t)
=> integral a/t dt = integral R'(t)/R(t) dt
=> alog(t) + c = log R(t) + d
=> alog(t) + c-d = log R(t)
=> e^(alog(t)+c-d)=R(t)
=> e^(c-d) e^(alog(t)) = R(t)
=> e^(c-d) e^(log(t^a)) = R(t)
=> e^(c-d) t^a = R(t)
=> A t^a = R(t)

>>9209349
Oh, I see. Thanks famo

>>9209268
The antiderivatives of [math] \frac{f'(t)}{f(t)} [/math] are [math] \log{|f(t)|} + c ; c \in \mathbb{R} [/math]
The antiderivatives of [math] \frac{a}{t} [/math] are [math] a \log{|t|} + c ; c \in \mathbb{R} [/math]
Therefore:
[eqn] a \log{|t|} +c = \log{|f(t)|} [/eqn]

and from that you get:
[math] \log{ \frac{|f(t)|}{|t|^a} } = c [/math]
which is equivalent to
[math] \frac{|f(t)|}{|t|^a} = e^c =: k [/math] where [math] k \in \mathbb{R}_{>0} [/math]
which is equivalent to
[math] |f(t)| = k |t|^a = |k t^a| [/math]
which means that
either [math] f(t) = k t^a [/math] or [math] f(t) = -k t^a [/math] where [math] k \in \mathbb{R}_{>0} [/math]
which is the same as saying
[math] f(t) = A t^a [/math] where [math] k \in \mathbb{R} - \{0\} [/math]

>>9209318
all right, so the feature that made determinants so important (hence the name) as well as the reason why they were introduced is that it tells you when an n*n linear system has a unique solution.
A system Ax=b with A an n*n matrix has a unique solution iff det(A) is nonzero (more accurately, it has to be invertible, but you don't need to worry about this yet).
Now how did people back in the day derive the formula for it ? Well as usual, it was a long process of trial and error that went on for a century or two until people figured out something that seemed to be working in many cases, then gave a general proof.
Another very important point is that you can consider the determinant of an n*n matrix as the oriented "n-volume" of the parallelotope generated by these n vectors (check that in dimension 2, the area of a parallelogram ABCD is the absolute value of the determinannt of the matrix defined by the sides AB and AC).
Now I'd write a long-winded argument to explain how these two interpretations can help us guess what the formula for the determinant has to be but it's late (yuropoor here) and I'm beat so I'll leave you with that and wikipedia.

What makes a pairing with alpha feasible?

>>9209488
>What makes a pairing with alpha feasible?
huh?

>>9209289
https://www.youtube.com/watch?v=Ip3X9LOh2dk
https://www.youtube.com/watch?v=23LLB9mNJvc

>>9209491
Sorry wrong image.

What makes a pairing with alpha feasible? This comes form the stable marriage problem.

>>9209453
>it was a long process of trial and error
I thought they derived the formula for a determinant of a system of two equations of two unknowns, and somehow based on that generalized it for n equations of n unknowns. The problem is, I don't know how that generalization works.
>"n-volume" of the parallelotope generated by these n vectors
sure, I can see that for two dimensions, but for more? I don't want to take it for granted, I want to know why it's the n-volume
>but it's late (yuropoor here) and I'm beat so I'll leave you with that and wikipedia.
thanks anyway.

>>9209307
>There are many ways to look at it
Like what?

>>9209498
It's feasible if there is a stable matching with that pairing.

>>9209543
Gotcha. Believe I got it.

I found that alpha B is the optimal, while alpha C is the pessimal.

>>9209502
>I want to know why it's the n-volume
Because the determinant can be defined as the unique (existence and uniqueness need to be proven) mapping from (F^n)^n to F such that:
1) det (e1,...,en) = 1
2) det is linear in each slot if you fix the other n-1 vectors (multilinearity)
3) det(c1, ... , ci , ... ,cj , ... , cn) = -det(c1, ... , ci , ... ,cj , ... , cn) (antisymmetric)

e1, ..., en form the unit cube and by 1) you get that it's volume is 1
if you take the unit cube and scale it by λ in the direction ei, then the volume becomes λ and this agrees with 2)
take the unit cube and add some other vector v=a1e1+...+an en to ei, then you can see...... just draw it.

I'm having trouble figuring out how to make this work. I understand that the first guy needs to get rejected twice and the second guy twice as well.

I've been experimenting with this:
http://sephlietz.com/gale-shapley/

but can only get 4 at most. I know 5 is possible though.

I've heard of people using "mental image" mnemonics for remarkable memorization and calculation ability. How can I build a mnemonic like this?

How can we show that the Gale-Shapley algorithm takes at most n^2 -2n + 2 rounds?


I know at most n^2-n+1 proposals can be made, but I'm not sure how this can be used to show it.

n proposals are made on the first day and at least 1 or more on each following day.

>>9209796
Is it it enough to say that since n proposals are made on the first day we really have

n^2-n+1 -n+1
=
n^2-2n+2

?

Or is that a stretch

(w+x'+z')(w'+y')(w'+x+z')(w+x')(w+y+z)

Is there an easy way to do this or am I fucked?

>>9209835
>Is there an easy way to do this or am I fucked?
To do what? All you gave was an expression

>>9209843
Simplify to sop form.

Please explain "a set of measure 0" to a retard.

>>9209845
define "sop form"

>>9209846
a set of measure 0 is a set in the pre-image of 0 of a given measure

Is there a resource that anyone recommends for understanding relativity better?

>>9209848
Sum of products form. I need to turn
(b+a)(b+a) into ab.

>>9209846
Well, in simple terms:
If you can cover the set with intervals in a way where the Sum of the lengths of these intervals can get aribitrarily small, then that set is said to have measure zero.

Basic set theory:

Is the highlighted part saying B is a subset of A? I’m confused.

>>9209885
Could you give some examples? Like every countable set has measure 0.

>>9209887
>Is the highlighted part saying B is a subset of A?
yes

>>9209902
but how can that be in that example? isn't A a proper subset of B?

>>9209904
>but how can that be in that example?
Because whatever you're reading is written wrong.

>isn't A a proper subset of B?
yes

and the highlighted part translates directly to "ratatouille is an element of B which is a subset or equal to A"

>>9209908
Thanks. Almost went mad trying to figure that out.
>tfw economists try to teach math
Pic related is the correct form from Cornell

>>9209891
Can you understand this one? :
https://proofwiki.org/wiki/Countable_Sets_Have_Measure_Zero

>>9209945
Not really. I get that any countable set has measure from googling around a lot, but I don't get that explanation.

>>9209922
>axiom of choice
It's simply false.

>>9207630
btw, this is equal to
[math] \sum_{j=1}^k \binom{N}{n_1 , \ldots , n_k} - \binom{N-1}{n_1, \ldots , n_{i-1} , n_i -1 , n_{i+1}, \ldots , n_k} [/math]

Alright, /sci/ I'm a fucking brainlet I can't remember how to interpret percentages. Tell me if these statements are correct:

If Stacy has 3 dildos when she used to have only 1 dildo,

1) She increased *to* 300% (of her original).
2) She increased *by* 200%.
3) She increased (to?) three-fold (of her original).
4) She increased *by* two-fold.

>>9209952
I'll try to explain it then.
Let X be countable. Since it is countable you can write it out like that:
[math] \{ x_1 , x_2 , x_3 , \ldots \} [/math] .

Now, we want to cover [math] X [/math] with intervals and we want these intervals to have a sum of lengths arbitrarily small.
Arbitrarily small means that if you are given a positive number [math] \epsilon [/math] (no matter how small), then you can find a way to cover [math] X [/math] such that the sum of the lengths of the intervals is smaller than that [math] \epsilon [/math] .

Say we are given an [math] \epsilon [/math] . We have to cover [math] X [/math] with intervals whose lengths sum up to a number less than [math] \epsilon [/math] .
Cover [math] x_i [/math] with the interval [math] ( x_i - \frac{\epsilon}{2^{i+2}} , x_i + \frac{\epsilon}{2^{i+2}} ) [/math]
This interval has length [math] \frac{\epsilon}{2^{i+1}} [/math] (the length depends on the [math] x_i [/math] .
The union of all these intevals cover [math] X [/math] .
The (infinite) sum of their lengths is equal to [math] \frac{\epsilon}{2} [/math] which is less than [math] \epsilon [/math] .

>>9210012
So whether a set is countable or not is the only way to tell if it has measure 0 automatically?

>>9209954
>lmao the product of nonempty sets is empty :^)

>>9210053
I don't understand what you are saying.

>>9210062
>[math]P \implies Q[/math], therefore [math]\neg P \implies \neg Q[/math]
>[math]\neg(\forall x : \phi(x)) \implies \exists x : \neg\phi(x)[/math] without excluded middle holding.
Completely, comically wrong.
>:^)
Just jump off a bridge, reddit fucktard.

>>9210122
>hurr I just believe arbitrary products of nonempty sets can't be proved to have an element :^)
yeah very fucking smart. modern math needs choice. it uses choice everywhere. stop being autistic.

>>9210119
I'm basically asking if a set of measure zero always has to be countable, and can a countable set not have measure zero.

>>9210135
>can't be proved
Exactly. But I don't believe this, it's actually provable.
>modern math
You wouldn't know anything about that since you're an engineer, as evident by your lack of understanding of basic high-school level logic.
>it uses choice everywhere
This is simply laughable and retarded.
>hurr
>:^)
>>>/r/eddit/

>>9210062
embarrassing

>>9210146
embarrassing

>>9210146
embarrassing

>>9210137
> if a set of measure zero always has to be countable
Νο, the Cantor set for example is uncountable and has measure zero.

>can a countable set not have measure zero
As I said/proved, countable sets always have measure 0.

>>9210156
embarrassing

>>9210194
embarrassing

>>9210194
>>9210196
embarrassing

>>9210193
Ok, I see.

I want to go into genetics, but I want to know just one thing
Is it fun?
I just can't imagine doing something that I don't enjoy for 8 hours a day for 30+ years of my life
desu I'm struggling to figure out if there's ANYTHING I would enjoy doing for that type of time, but genetics is the hotbed so that's what i'm looking at i guess

>>9210339
>I just can't imagine doing something that I don't enjoy for 8 hours a day for 30+ years of my life
>desu I'm struggling to figure out if there's ANYTHING I would enjoy doing for that type of time

Whatever you're interested in. You should try going for it and see if you like it. You'll find out if you don't while you're still in school. Most people go through that stage where they think "well I AM interested in X but I couldn't even IMAGINE doing that 20-40 hours a week for 30+ years", but it's not really like that. It doesn't feel nearly as repetitive as it sounds. You should speak to your adviser about it, since it's something pretty common to worry about.

>>9210385
bro i'm interested in everything, but I don't know what the actual work looks like for anything
And I don't wanna find out I don't like something while i'm still in school
I mean doesn't that happen to some people like a few years in?
And then what if I find out I don't like it, choose something else, then find out I don't like that too?
I realize I'm asking a lot of questions so let me just stick to the main point.
You're telling me I should go for whatever I'm interested in, but I can only gauge my interest on a surface level understanding of the fields. It seems to me that the actual work might be way different from my surface understanding, so I don't know if my gauge for interest is meaningful at all.

>>9210394
You'd be surprised how common it is. I used to be in that rut too, stretched between math, electrical engineering, and computer science.

I said to try it simply because if it's close enough to what you want to be, you find out from your 1-2 major-related courses that you have your first year that you don't like it as much as you thought, switching probably won't set you too far behind.
Many students take a fifth year because they switched so much, so don't be too surprised if this happens to you.

A good way to discover what you do and don't like is doing internships. Yeah, you'll basically be a slave for a summer, but you'll at least get a glimpse of what your daily life would be like (by observing others) working that job.

Above all, you should speak to your advisers about what you should do. There's only really 3 reasons people talk to their advisers. 1. course schedule fixes. 2. anything to do with transferring. 3. figuring out what the hell to major in.

Also do note that whatever you major in doesn't mean that all jobs will be the same. So don't think that going into mechanical engineering is a waste because SpaceX works their employees to death, as that's just SpaceX.

If you list all your interests I might be able to find some stuff for you to look at and see if it's actually as good as it sounds on the surface level.

>>9210401
well, as i said, i'm pretty much equally interested in everything
something I didn't mention is I'm also extremely ignorant of everything tbqfhwyfam
but in the interest of job security, availability, etc. i supposed i would be most interested in genetics, because i heard damn near every other bio field is very shaky in those aspects. oh and also i'm very interested in nutrition, but really unsure about a career in that.

>>9210411
Well i'm guessing you're not interested in a math major or a computer science major

It sounds like you're interested in biology/chem related fields. Problem here is that biology and chem are two of the very few fields that I don't like and don't know much about, so I can't give you any resources that would help determine what you want to be.

Only real advice I have for you at this point is to speak to advisers and even other professors in those fields.

If you've already started uni, you have plenty of time but I urge you to do it sooner rather than later. If not, then I'd advise you to do plenty of research online (e.g. google "genetics jobs" and learn what it's all about) to get at least some idea. Look for flaws, be pessimistic (unless you end up accidentally narrowing down and eliminating everything, in which case just lower your standards).

If you're socially awkward or whatever, just realize that speaking to other professors is a luxury you have that you paid for. Not talking to them out of fear is a waste of money. You essentially get free connections for 4-5 years complimentary, so use them.

>>9210419
ok
i mean i dont even know if this bio thing is truly what i'm interested in, i'm a shitshow. i started reconsidering comp sci today, so what could you tell me bout that?

>>9205938
Its x^((1/2)(x^(1/2)))

>>9199462
any chromatographers or chemists who are well versed in LC?

what does a log k vs solvent concentration plot tell me?

>>9210339
>I just can't imagine doing something that I don't enjoy for 8 hours a day for 30+ years of my life

then I guess you've never had a stable job

genetics isn't a guy in a white protective suit injecting frog dna into oldass dna from some asshole dinosaur dna, grab a book and leaf through it see if it catches your attention

concept of genetics - klug 10/11th ed

What is the physiologic advantage for having the hiccups over not having it?
Why did we develop this annoying shit?

>>9209846
You need to understand what a measure it, it is a function from a subset of a given set (this is a lot more complicated) to the Real numbers and infinity.
(If you do not understand what some of these words mean you need to read up on them, they are VERY essential to understand what "a set of measure zero is")

One example is if you look at the set {1,2,3} and you want to assign a "size" (very generally speaking) to each subset of this set.
One example of such measure is the "counting measure" which simply counts the elements.

Let [math]\mu()[/math] be such a measure then [math]\mu(\{3\}) = 1[/math] since [math]\{3\}[/math] has one element.
And [math]\mu(\{1,2,3\}) = 3[/math] since [math]\{1,2,3\}[/math] has exactly three elements.
Also the empty set is always a subset of your given set so we have [math]\mu(\{\}) = 0[/math] since [math]\{\}[/math] has exactly zero elements.
If [math]\mu(A) = 0[/math] then we call A a set with "measure zero".

It is generally false to say that "countable set have measure zero", a counter example is given above.
You can have man many different measures and the counting measure is just an example.

There is also the "Lebesgue-measure" with generalizes the way we (as humans) perceive distance.
For this measure (and all other measures) the empty set has measure zero but from geometrical intuition alone you will understand that a single point also has "Lebesgue measure zero".

Since a countable set is a countable unification of single points, again geometric intuition tells us that if you put countable many points without any volume together they will still have no volume.
This means that any countable set has measure zero, mathematically this is expressed by [math]\mu(\cup_{i=1}^\infty \{x_i\}) = \sum_{i=1}^\infty \mu(\{x_i\})[/math] which holds true for any disjointed sets (instead of [math]\{x_i\}[/math] which is a single point you can put any subset [math]\{A_i\}[/math] which is disjoint from all other[math]\{A_i\}[/math]).

>>9209978
The first three are correct, I'm not sure about the last but english is not my mother tongue.

Is the operator [math]A(f)(x) = \int_0^\pi \sin(x-y)f(y)dy, 0 \leq x \leq \pi [/math] self-adjoint, where [math]f\in L^2([0,\pi])[/math]?

I think I've managed to show that [math]A[/math] is self-adjoint if [math]f\in L^2([-\tfrac{\pi}{2}, \tfrac{\pi}{2}])[/math] but I don't know if this implies that it is also self-adjoint in [math]L^2([0, \pi])[/math]

>>9210429
Sorry, I went to bed.
Comp sci is a huge field with tons of applications, ranging from managing databases, creating or maintaining software in large development groups, handling cyber security, and some other things I'm forgetting.
Being a sysadmin is, from what /g/ tells me, a great job with little downsides. You basically handle upkeep, configs (includes making some scripts sometimes), and basically does the same shit as IT. I don't know why but something tells me that /g/ is wrong about this one.
Software engineering (which on average makes more money than sysadmins) is basically about everything listed here https://hiring.monster.com/hr/hr-best-practices/recruiting-hiring-advice/job-descriptions/software-engineer-job-description-sample.aspx and then some.
Database admins do everything listed on https://www.prospects.ac.uk/job-profiles/database-administrator which is pretty comprehensive.
Note that computer science majors can still get jobs as software engineers, it's not like you're bound to only CS. If you did computer engineering with a double major with CS, you'd have a good range of possible jobs.

>>9210838
Correct me if I am wrong, but isn't it just fubini?

>I think I've managed to show that
I highly doubt that, again correct me if I am wrong, but I see no reason why Af would be defined for such an f.

>>9210551
It has something to do with digestion, especially in babies.

>>9210547
>I guess you've never had a stable job
righto

>>9211214
dude what are u some sort of sci god
thanks isn't long enough of a word to show my appreciation
you've helped me a lot

>>9210547
and thanks btw

>>9199462

Can somebody give me McIlvaine's buffers reaction mechanism, and tell me if it's toxic to most fungi like yeast?

I fucking HATE java and I don't think I fucking care with what I finish with in this course so long as I pass