/sci/ - Science & Math

Can somebody walk me through on how to write the distance [math] \frac{1}{ \left\lVert\vec{r} - \vec{r}' \right\rVert } [/math] of a charged ring? I want to find the potential but i keep getting something wrong with the distance term. Thanks

>>10841379
Since girls have wider hips, can they poop more easily?

>>10841504
https://www.vox.com/2015/1/22/7871579/poop-feces
Will get back to you if I find a better source.

>>10841379
As a "humble" "newbie". I ask: what books & study methods do you reccomend to become a meme mathmagician like Paul Erdős (őwő űwű)?
(without illegal drugs)

Maybe NoFap like Terry Tao?

Which books do I download from libgen.is ?

Maybe Linda E. Reichl's
The transition to chaos: conservative classical systems and quantum manifestations (Springer)

The appendix "Q" seems very interesting. Is it a good start or not?

Perhaps Jonathan L. Gross's Handbook of Graph Theory (CRC)?
To make better Demonic Sigils for my Kabbalistic Chaos Magick Rituals to summon my Succubus?
(I like the Baphomet pentagram & the Kabballah's Tree of Life )

Or maybe just the very basic physics and computer science as
Masahito Hayashi's Quantum Information Theory: Mathematical Foundation. (Springer)

You know that physics and computer science need rigourous proofs right? In order to create an AI supercomputer that will enslave the world.
You know... Our Universities need supercomputers.

Also Daily reminder that we must invest in Embryos DNA editing to make Nekopara's Genetically Engineered CatGirls to serve us the Autistic Übermensch Master-race overlords.
You know... Researchears need fundings. To cure cancer, you know.

El Psy Kongroo ... Tutturuu
Praise KEK (Kamiokande) over CERN.
& Praise the Sun (Amaterasu)

Remilia Scarlet claimed as waifu (i.e. muh Succubus)
https://www.youtube.com/watch?v=4jJlraFHbvs

Because as Schrödinger's cat I always wander between Yesod and Lilith on Kabballah's Tree of Life Graph

Am I dead or alive? I don't know ... perhaps due to quantum superposition it's both at same time or in parallel universes.

t. Schrödinger's cat

>>10841511
I have found other sources, but they're all shit. Tough luck.

I need help with this physics problem.
I posted on /adv/. >>21179039

>>10841859
I don't know how to direct to another board. >>>/adv/21179039

>>10841392
"distance of a charged ring?". You mean the distance between a given point and a ring? The set of points a fixed distance from a ring forms a torus, described by the implicit equation
(√(x^2+y^2)-R)^2+z^2=r^2
where R is the radius of the ring and r is the distance of the point (x,y,z) from the ring. So swap sides and take the square root to get r as a function of x,y,z.

No joke, How do I get smart?

>>10841877
Non-conformity.

We give special attention to fractions, roots and logarithms, but what about solutions of hyperoperations? For instance, define 3^^2 = 3^3^3 and generally x^^n = x^...^x (n x'es), then we can have a super-root of 2 called a such that a^^2 = 2. This can be easily generalized to any number of ^'s, and we can consider the left and right inverses of each.

A subset of reals containing all inverses (being a specific case of closed form expressions) seems like a sensible concept. Is there any research done on this, or is it maybe not useful after all?

>>10841877
If you are not smart, you make up for it through extreme masochism... I mean hard work.

>>10841877
You'll have to wait to real-time genetic engineering comes out. That way you can modify your intelligence genes for the maximum amount of intelligence desired.

>>10841966
Yah, but it doesn't really show up in practical applications as much as polynomials do. See:
https://en.wikipedia.org/wiki/Tetration , specifically open questions at the end, and the bibliography.
>>10841877
Prayer.

>>10841991
I'm aware of tetration, but thanks for referring me to the open questions anyway. The concept that transcendentals like e and pi can happen to be the product of a conceptually simple operation like a hyperoperation was precisely what was on my mind.

>>10841999
Not much is known. It's not even known if pi^^4 is an integer.

Does anyone have a link to a good PDF of Apostols Calculus, Vol 1? All I can find have weird stretched text and shit, with random wordsarger than others. That's all I can find on LibGen and B-ok.

>>10842175
use djvu reader there are no pdf versions on those sites that are clean. you can also convert djvu to pdf

>>10841877
>>10841965
>>10841968
Maybe. But how do I retain short term memory and increase observation skills? Can't tell you how many times I've either missed something that was right in front of me or promised myself I'd do something and just to forget about it a minute later.

>>10842243
>no short term memory, can't properly pay attention or focus
Good sleep, unironically. Try having breakfast, hydrating, and maybe jogging.

>>10841877
eating proper food, getting proper amount of sleep and regularly exercising your brain may help

>>10841379
What is "single photon".

>>10842243
>short term memory
you don't
>observation skills
you don't

>>10841504
Girls with tails have it different.

at what math level/in what math class (for a standard american university) are complex numbers an complex functions introduced at an elementary level?

The last time they were brought up was in Trigonometry when we were introduced to the complex sine function and the argand plane

Now I've taken up to Calculus II, and there doesn't seem to be any mention of them in Calc III or Diffeq (even though Diffeq requires the laplace transform)

so what gives, when are they going to be introduced?

>>10842461
i mean you learn complex differentiation and integration in complex variables / complex analysis, which you'd probably take after real analysis. you would also probably use complex numbers quite often in linear algebra, where many times you have complex valued matrices and vectors. but for complex functions you'll have to wait for complex analysis.
the reason you wait so long is because complex differentiation is extremely restrictive and complex differentiable functions have tons of great properties, but you can only prove they have those properties after doing some introductory analysis.

How to prove for positive integers n and k? I've tried induction but it doesn't seem obvious. AM-GM seems the most likely but just using the sums naively is not the way to go. Pls help.

>>10842588
the problem is I'm a brainlet engineer. I'm very much interested in complex analysis and will (try) to study it in my own time, but an actual complex (and real, for that matter) analysis course is just not part of an electrical engineering curriculum, at least not at my university

>>10842620
you're not going to take complex variables? at very least a nonrigorous complex calculus class is nigh essential for EE, if not a rigorous one.
it's all very fun and interesting, would recommend you try and take it. it can only be useful too.
i'm sure you linear algebra stuff will feature complex vector spaces.

Why does alcohol make one feel good?

>>10842626
See, that's what I'm so confused about. I might just be reading the major flowchart wrong, but I don't see it anywhere in there.

Yet EE so strongly depends on the Z transform/laplace transform and the fourier transform, on top of complex vector spaces... it's practically applied complex analysis. I don't see how there can be an EE curriculum without any introduction to complex analysis. It's so fundamental to the field as a whole.
At the very least, I guess I can take real and complex analysis as electives

>>10842598
what's so bad about induction? for n = 1, it holds for all k > 0
then we just need to show it for fixed k and inducting on n
well, how about the first inequality? we want to show that 1^k + ... + n^k < (n+1)^(k+1)/(k+1). well using the binomial theorem to expand we know that (n+1)^(k+1) > n^(k+1) + (k+1)n^k, since the rest of the terms are positive. now we have n^(k+1)/(k+1), which we know is bigger than 1^k + ... + (n-1)^k by the inductive hypothesis. we also have (k+1)n^k/(k+1) = n^k. added together, that's what we want! so the first inequality is proved for n,k > 0.
now give it a shot in a similar way for the other inequality. maybe the binomial theorem could help again.

>>10842635
i mean sometimes they just have a signal processing class which gives a sufficient overview of how to use the fourier transform without going too in depth about it, since it's just a real integration of a complex valued function, not a function OF a complex variable.

>>10842638
Ah, I was fixing n and doing induction on k. Not sure why I didn't consider the other way.

>>10842655
oh jesus. well it might be doable that way but i cant see how.
just to mention, the reason i thought to handle n instead of k was that for k you have to increase all these powers while for n you just pop on an extra term. whenever you want to prove such a summation statement by induction it's typically nicer if you can change/add just one term instead of having to adjust all the terms in your sum. of course it doesn't always work that way but it often does. helpful kind of heuristic for riemann sum proofs.

I've taken up to (and failed) Calc II.
Usually when you go to solve a problem (or etc), you can formulate a mental "plan of attack". "I want to isolate x" -> start moving constants, coefficients, variables around, start factoring, doing inverses, etc.
"I want to take the derivative of f(x)" -> re-arrange the function such that it can be differentiated, apply the chain/product/quotient rule.
So on, so forth.

A vast majority of the time, when I'm presented with an even slightly complex integral, that shit just flies out the fucking window. I don't know what it is about them that does this, it just... happens. I blank. Half the shit I see in solved problems I would never even think to do.

in other words, a lot of the time when I'm presented with a random integral I'll just have no idea how to even start integrating it. I know fundamentally there's only two operations you can do - u substitution and integration by parts, but that doesn't help much, at least for me

how can I alleviate this predicament of mine? Is this the true meaning of the legendary "integration is an art" quip? Is it just a matter of practice and experience?

When you press a button, you have a 97.8% chance of getting yellow, .7% chance for red, and 1.5% chance for brown.
You can press the button up to 203 times.
Is it true to say that to get red, the success rate is 1-.993^200 = 75% and to get brown the success rate is 1-.985^200 = 95%?
What would be the chance of getting both?

>>10842672
Unironically practice. I used to teach gifted little shits at a Kumon. And the integration worksheets are very good at teaching different techniques. See if there’s one around and ask/bribe the instructor to give you worksheets from level O that involve integration techniques. You can get the solutions manual it’s pretty good.

How do I solve this for x (analytically)?

>>10842672
You pick up certain heuristics along the way. If it's a trig integral remember the half and double angle formulas and see if something cancels, in the same vain if the memory of trig functions pops up in a "normal integral" try the trig substitution method etc.

>>10843256
Ok lil nigga let’s try. Multiply everyone by log(x - 1), so that
>log(x) - 1 = 2log(x-1)
>log(x) - 2log(x-1) = 1
Now using the power rule of logarithms
>log(x) - log(x-1)^2 = 1
>log(x/(x-1)^2) = 1 = loge
>x/(x-1)^2 = e
Then
>x = e(x-1)^2 = ex^2 - 2ex + e
>ex^2 -(2e + 1)x + e = 0
>x^2 - (2 + 1/e)x + 1 = 0
(I do this to input just one long decimal into my calculator 2+1/e = 2.3679)
Using the quadratic equation: x = 1.82 or x = 0.55. Now we have log(x - 1) in the original equation, and we can’t find log of a negative number, so we reject 0.55, and are left with 1.82. Check with your graph, seems to be it.

>>10843104
>7%
Did you mean 0.7%? It sums to 100% then.
Also, what's a success and what's a failure?

>>10842672
You need to learn all of the common cases so that you can recognise them when they appear. Integration of parts replaces one integral with another, so you need to be able to identify a factoring into uv' such that u'v is something you can integrate, while u substitution requires identifying an appropriate substitution. Sometimes u is just a subexpression, but if you have anything resembling √(x^2±k), it's probably going to be a (circular or hyperbolic) trig function where the function is related to its derivative by Pythagoras.

Integration is one of the first things you learn which isn't essentially a mechanical operation.

>>10843324
>Now using the power rule of logarithms
>>log(x) - log(x-1)^2 = 1
Ah thanks, completely forgot about this.

>>10843337
No problem anon. But also fuck women they’re useless holes and have no place in my life. No homo either. Thankfully I’m fucking off to a place with barely any women where I will do math full time, thanks be to God.

>>10843342
Most of successful scientists and mathematicians were turbo normies though.
Gauss - wife and kids
Grothendieck - had multiple children by multiple women (supreme genetic fitness)
Galois - died over a woman
Cauchy - wife and kids
Russell - multiple women, kids
Nash - wife and son, also had a bastard son
Von Neumann - wife and kids

>>10843345
>Gauss
>horrendous father, extreme bouts of depression
>Grothendieck
>dropped everything to live innawoods
>Galois
>literally died in a duel, was some sort of revolutionary
>Cauchy
>literally the de Maistre of maths
>Russell
>felt it was okay for husband and wife to cheat on each other if they could keep up a family environment for children
>Nash
>are you fucking serious
>von Neumann
>literally came up with and implemented mutually assured destruction
>turbo normies

>>10843415
I am sorry for not defining the terms properly, I used /r9k/ lingo in which a "turbo normie" implies reproductive success and nothing more.

>>10841379
alright /sci/ i have been working as a """""data scientist"""" for a bit over a year. I graduated with a degree in management science/industrial engineering, however most of the work i did with this company is menial data cleaning. Now that I am more financially stable and can afford to leave, I want you to shill me some good refreshers for the following topics:
1- business statistics
2- probability
3- forecasting
4- econometrics
5- algebra and calculus (with focus on statistical applications).

I became quite rusty and stupid thanks to my shitty employer and I need to get my act together by crushing through the books.

Thanks in advance.

>>10843415
>>felt it was okay for husband and wife to cheat on each other if they could keep up a family environment for children
what's wrong with that

>>10843523
Nothing cuck anon. Nothing at all.

>>10843523
Alright back you go

Am I stupid if I can't derive a formula for sum of squares of first odd [math]n[\math] numbers?

>>10843685
Depends, do you know the sum of squares formula?

What jobs could I get if I studied biology, and what jobs could I get if I studied biotechnology?
Could a biotech graduate work in cybernetics or is that more for engineering guys?

can "insufflate" be considered a contronym?

>>10843703
Yep

>>10843805
Then yes.
Tip: try summing all of them and removing the ones that can be written as 2n.

>>10843685
Pretty much. You know it has to be a cubic, so just expand out f(n)-f(n-1)=(2n-1)^2, equate terms and solve for the coefficients.

>>10843811
You want me to remove all even ones anon. I don't have formula for sum of even squares.
>>10843818
Eh?

>>10843518
BJ giver

>>10843849
(2n)^2=4n^2 anon.

>>10843855
Kill me

>>10843518
>business statistics
Dunno.
>probability
Shirayev.
>forecasting
Applied Time Series.
>econometrics
Hayashi.
>algebra
Grillet.
>Calculus
Royden.

>>10843849
If s(n) denotes the sum over i=1..n of x[i], then s(n)-s(n-1)=x[i], i.e. the difference between successive values of the sum is the last term which was added.
Now suppose that s(n) is some cubic polynomial:
s(n)=an^3+bn^2+cn+d
=> s(n-1)=a(n-1)^3+b(n-1)^2+c(n-1)+d
= a(n^3-3n^2+3n-1)+b(n^2-2n+1)+c(n-1)+d
= (an^3-3an^2+3an-a)+(bn^2-2bn+b)+(cn-c)+d
= an^3+(-3a+b)n^2+(3a-2b+c)n+(-a+b-c+d)
=> s(n)-s(n-1) = (a-a)n^3+(b-(-3a+b))n^2+(c-(3a-2b+c))n+(d-(-a+b-c+d))
= 3an^2+(-3a+2b)n+(a-b+c)
Also: s(0)=0 => d=0

IOW, the difference between successive terms of a cubic sequence is a quadratic sequence <=> the successive sums of a quadratic sequence form a cubic sequence. More generally, for a sequence whose terms are given by a degree-n polynomial, the sum is given by a degree-n+1 polynomial.

The sequence of squares of odd numbers is given by x[n]=(2n-1)^2=4n^2-4n+1. So
s(n)-s(n-1)=x[n]
=> 3an^2+(-3a+2b)n+(a-b+c) = 4n^2-4n+1
=> 3a=4, -3a+2b=-4, a+b+c=1
=> a=4/3, b=0, c=-1/3
Ergo, s(n) = (4n^3-n)/3 = (4n^2-1)n/3 = (2n-1)(2n+1)n/3 = (2n-1)2n(2n+1)/6.

>>10843329
I did say .7%
Success is landing on that color, failure is not landing on that color

Since the old /sqt/ pasta was way too long (not to the /g/ or the /diy/ extent, but still to the "people won't fucking read it" extent), I've been thinking about writing a new one with just the absolute bare essentials.
So something barebones like :
>Check if your question doesn't fit >>>/diy/sqt or >>>/g/sqt better.
>Try to be clear.
Anything else?

>>10844355
Just remembered, gotta link to the Latex guide.

>>10844181
Ah, right.
Your calculations are correct.
There are two possible cases where you fail at getting both (presumably red and brown). Either you get yellow and red in all of them, or you get yellow and brown in all of them. The chance of getting red or yellow is 98.5, and the chance of getting brown or yellow is 99.3. For all of them, that's 1-(98.5^200+99.3^200).

>>10844383
Ah, I forgot the intersection. The chance of getting yellow in all of them is 97.8^200, which we add back in since we counted it twice.

Has anyone here had sucess with time scheduling or to-do-lists to deal with procrastination? I'm not sure if this stuff even works so I'd love to hear some experiences, software recommendations and methods would be nice too.

How the fuck do I solve this shit?

>>10844697
Refer to any text in linear algebra or matrix algebra, i.e. Strang, or, alternatively, the wikipedia page for one of the following:
Gaussian elimination.
Systems of linear equations.

I just realized I might have insomnia because my body isn't moving.
Should I tire myself to sleep ?

>>10844737
Yes.

>>10844697
Solve for which variables? If you're solving for x,y,z, then trivially x=y=z=0 is a solution. Depending upon the values of α,β,γ, there may be other solutions. Specifically, if α^2+β^2+γ^2=αβ+βγ+γα; but if α,β,γ are real, that can only happen if α=β=γ.

>>10844805
Thank you! I see it now. Pretty tricky stuff.

>>10842598
Still having issues with the right inequality here. I'm really struggling.

>>10844914
Pass the k+1 multiplying to the other side.
If k+1>=n, it's trivial.
Assume k+1<n and induct on k.

>>10844693
Best way to beat procrastination is just force yourself to do it.

>>10844990
I see how it's trivial when k+1>= n, but I don't know how induction on k helps.

Where do I start if I want to get into Math/Physics after ignoring it since high school?
Will I have to go through a lot of worksheets and other forms of practice, or for the most part can I just learn by reading like i've done studying History up to this point, with moderate practice just to confirm i've learned it?

If I can see the moon during the daytime in North America, does that mean Australia can’t?

>>10845365
you can't learn mathematics or physics without doing exercises

>>10845375
no, they just see the other side of the moon

>>10845387
Please explain

>>10844914
dont listen to that other idiot. why is (n+1)^(k+1) less than n^(k+1) + (k+1)(n+1)^k? well, what's the coefficient on n^j? in the first, it's (k+1) choose j, on the second its (k choose j) times (k+1). just write these down and see which is bigger.

>>10845503
Thanks man. Normally these types of proofs come to me easily, but this inequality just stumped me.

>>10845365
You have to actually solve about 5000 questions in total spread over various topics to have ‘learnt’ Math. You don’t learn math or physics by reading, only by doing.

is zoology a meme degree?

>>10841379
What's she drinking?

I'm hoping I can study trig and calculus without having to pay for classes.

I know Khan academy and similar platforms have something, but is it possible to learn this shit alone? Is it faster?

>>10845715
Yes I did it. Get this book

>>10841379
we need more is threads

>Want to study Software Engineering at university
>Have to learn math from Algebra to Calculus
>Have no problem with that and fully accept that
>Said university (the best in my state and in the top 6 in my country) requires me to have studied physics as well

Literately why? If I'm not doing game's programming (wouldn't touch that with a 10ft pole), why would I need physics to code?

>>10845671
yes, unfortunately it is a good way to get into debt and end up unemployable
>>10845715
Apostol Calculus Vol I-II is the best book I think

>>10845855
you do realize that programing on a computer is what a writing on a typewriter is to a novelist right?
Programing is just a tool to translate your mathematical description of something in digital form.

is bluetooth safe long term? I don't worry about many thing but I'm currently shopping for new headphones and found some bluetooth ones with active noise cancelling which is ideal, 30 hours of battery and can be used wired however a part of me wonders if using bluetooth next to my brain for 12+ hours is safe so is this something I should worry about? sources would be very helpful

>>10845365
>You don't understand math, you get used to it.
t.Von Neumann

>>10846039
>is bluetooth safe long term?
Do you live around WiFi?
The most surely it will make very little difference.

>>10845855
>Literately why?
Because "Learning how to code can be taught in a month", if you wanted to learn how to program just do it.
You University offers you an EDUCATION which means you aren't just supposed to know HOW to do something but also WHY things are the way they are.

Understanding how a computer operates and programming something which you can't outsource to India for 1/10 the price requires that you have a deep understanding of WHY things are what they are.

On the most fundamental level you haven't understood what a degree is supposed to be about.

>>10845886
I suppose you're right.

>>10846120
>you aren't just supposed to know HOW to do something but also WHY things are the way they are.
That's what I'm confused about though. I really don't understand why I should learn physics just to be a software engineer. I'm not taking pride in this or shitting on the profession, I honestly just don't know. As far as I know, you'd only need it for game development (because of physics in gaming engines etc), not so you can get your foot in the door as a coder/programmer etc.

>On the most fundamental level you haven't understood what a degree is supposed to be about.
I really want to learn more about it.

>>10841877
Be born from smart parents

>>10845855
"Physics" will most likely consist of electrical engineering and how basic circuitry and its components work and why they do
If its materials/hydrodynamics then tough luck

>>10846140
>not so you can get your foot in the door as a coder/programmer etc.
No, you do not need to know about physics to "code" some application for some shitty company, but you also do not need a degree for that, a month in some coding Bootcamp and some contributions to a few projects should be more then enough to reach that, far cheaper and less time consuming.

>I really don't understand why I should learn physics just to be a software engineer.
The principle mechanism which underly any computer are based upon physics, aside from that the areas in which a programmer has to understand the basic principles of physics are innumerable.
Just think for a second about what things are controlled by software, cars, planes, screens, lights, machinery, entire powerplants, etc., etc..

For mathematics it's even worse, if you want to do anything that isn't very basic application development that most certainly isn't paid very well you need mathematics.

Your education is NOT about you learning "how to code", every idiot can do that, and it doesn't take 3 years to learn, but maybe 3 months.
You are supposed to have a fundamental understanding of the subject and a wide array of skills, which is the only thing that sets you appart from a guy in india who takes 1/10 of what you would be payed.

>>10846155
That's what I don't understand, anon. Isn't SE mainly coding? Why would I need to know about electrical engineering, basic circuitry etc?

>>10846167
>No, you do not need to know about physics to "code" some application for some shitty company, but you also do not need a degree for that, a month in some coding Bootcamp and some contributions to a few projects should be more then enough to reach that, far cheaper and less time consuming.
I won't make good money from that though, will I? I want to do SE or comp sci to make good money for myself.

>Just think for a second about what things are controlled by software, cars, planes, screens, lights, machinery, entire powerplants, etc., etc..
I had a feeling it'd be about things like that, so I guess it's unavoidable.

>For mathematics it's even worse, if you want to do anything that isn't very basic application development that most certainly isn't paid very well you need mathematics.
Oh yeah, of course. I've accepted that and I'm more than willing to learn what I'll need to know.

NOW it makes a lot more sense.

If you guys working SE, do you mind if I ask what you guys do from day to day? I'd like to learn more.

How do I have a son? 33 y/o with a s cond daughter on the way and am feeling the walls closing in.

Can someone link/lecture me on nuclear power? Is it really bad as people say or do they just not understand how it works?

>>10846571
Nuclear power can be perfectly safe (well, as safe as anything can be in this world). The main requirement for that is that it needs to operate in a society with honest government. Because otherwise it's just so much cheaper for the operators to bribe the government to turn a blind eye than to actually do everything properly.

Also, if they are doing everything properly, then nuclear power isn't really economical. At a minimum, you need to be able to dump most of the costs of decommissioning and spent fuel storage onto the public, because both of those are likely to exceed the plant's total lifetime revenue by a large margin.

>>10846765
>a society with honest government.
In other words, no society ever in the history of the planet Earth.

(a + b)3 = a3 + 3a2b + 3b2a + b3
i just don't get where's the of the pieces are

Would there be any disadvantage if the world were to only have exceptionally gifted people? would there be any issues?

>>10847092
That situation could go one of many ways. Consider an idealized society.

What is your idea of an idealized society? It may and likely does differ from that of another man. Consider the top intellectuals of the world. More than likely they have some aspects of similarity in their personal habits and behaviors--but it's also likely they have a difference in opinion about what the idealized society looks like--and along with that, how to either govern or rule over a populace. (Paying certain special attentions to either morality or efficiency when it comes to the means by which the populace--given individual interests-- is dealt with.)

It may be the case that we would have complete peace and unity--focusing on things like mental health, problems which prevent peace, issues that cause general malaise and discontent...

Or we could end up with highly specialized factions of individuals who compete with each other in a sort of "arms race," gradually increasing collective knowledge through the need to increase the scope of available techology to ensure success and maintain dominance.

Really, it could go any number of ways. Sentience is very much not a clear-cut science, to the best of my knowledge.

Why do we panic ?
Why are we disgusted ?
Wouldn't this traits kill us ?

>>10847092
Probably not, but that would be boring I guess.

Hey, lads.
In my uni, "bachelor's thesis" is essentially a subject, and we can just add it to the list of subjects we want to get for a semester.
Do you think whoever became my advisor would kill me if I took it a couple semesters early? I've seen a few from people later on in my course, and I'm fairly sure I could make something substantially superior.

>>10846253
1. stop being a creepy sexist
okay there you did it
>>10846933
please write a question in a way someone can comprehend and respond to it
>>10847092
what's to say we aren't in such a society now? gift is relative.

>>10847161
We panic so that we try to run and escape in times of immediate and life threatening danger without trying to be clever.
We are disgusted so that we don't eat or touch things that are going to kill us.
Why would either trait kill us?

>>10845396
southern hemisphere

Can someone explain odds to me?
If I put 6/1 odds into google, it gives me a 14.29% probability. But how is this calculated? If I divide 100% by 6, I come out at 16.66%?
What kind of magic is odds math that it comes out as 14.29%?

>>10847949
1/(6+1).
1 to 1, for example, means that both events have the same chance of happening, and thus each happens 50% of the time.

>>10847988
Alright, that makes sense to me, so it's a basic fraction but you add +1? So 16/1 woud be 5.88%?
I guess if you calculate 100/(6+1) you get the correct decimal.

>>10848051
>>10847988
Oh shit, out of pure confusion I forgot to say thanks.

Thank you anon, of course. Sorry for forgetting that.

>>10848051
Yeah. Putting it better, "a to one" says that the ratio of the chances of the events is a.
So if "two to one", the first event happens twice as often as the second. Mathematically, the chance of the latter is just 1/(a+1).

>>10848051
>>10848066
Sort of, but not quite. If I say that the odds are 5:3, I mean that for every 5 losses you should expect 3 wins. So the probability of a win is 3 / (5 + 3) = 3/8 = 0.375.
Saying "6 to 1 odds" is different from saying "a 1 in 6 chance", 6 to 1 odds means you'll win 1 time for every 6 times you lose (so 1 out of every 7 times you play) while a 1 in 6 chance means you'll win 1 time out of every 6 times you play, which is 0.1667.
Odds are weird terminology which very very few people in math ever use.

>>10848085
Thank you.

>>10848090
Ah. as a non-native english speaker I guess I just assumed that "odds" and the x in y chance were just synonyms, but explaining it as "1 to 6 means if there are 7 games you'll like win one" explains perfectly where the +1 comes from that confused me at first.

Thank you very much Anons, this has been very helpful.

Should I quit my job to focus on school? I don't pay for bills other than my car payment which is only $170. I have $10k saved up and I have 3 semesters left of college.
I could use the time off work to focus on studying and looking for internships.
Should I do it?

How long should it take to learn Algebra 1/2 by using Khan Academy? I know everyone learns at different rates (I was shit with math in high school because I was lazy and had useless teachers), but want to learn it so that I can get a good career.

What's /sci/'s take on it? That way I have a rough idea if I'm taking too long etc.

I'm a biochemistry undergraduate who wants to work in the biotech cluster of an investment bank/hedge fund. Should I minor in finance, or math?

>>10848581
here's a cute Asian girl so that people might answer my question, I know it's very stereotypically /sci/ but I'd appreciate an answer anyhow

>>10846933
Not sure this is what you're referring to, but the remaining 3 ba^2 blocks are the square faces that you can see in the image. The a^3 cube is hidden behind them.

>>10847592
When we panic we like freeze for like 5-10 seconds before running away.
When we see other people with nasty injury instead of helping we feel disgusted.

>>10847949
All the odds are 7. 6 favor thing A, 1 favors thing B.
6/7 is the probability that A wins.
1/7 that B wins.

>>10847949
>>10848920
Also, another example is 5:3 odds
You get 5/8 and 3/8.

What subjects are worth going deep into, in your opinion?

>>10848581
>biochem
>investment bank/hedge fund
They will use mathematicians for the math, and finance gurus for the finance, so the minor won't matter. Maybe take stats or CS. I've never heard of someone going into bio or chem to work in finance though, sounds retarded.

>>10848388
major? I would finish regardless if you only have 3 semesters left.

>>10849440
farmacotherapy of mental diseases

>>10844693
I use org-mode and org-agenda, works great. I find I absoluely hate doing things if I micromanage myself too much though (like, telling myself what specific task to do at what time). So instead I have 'sessions', I study in the AM and PM, where I just look at the list of things and pick some. The remainder of the day I look at my 'important' list, which contains important things not related to studies, and the rest of the day I workout and chill.

Can we have a brainlet meme thread going?

>>10849454
Electrical Engineer.
What do you mean by finish regardless? Keep working at a job I hate?

>>10841379
How retarded am I guys? Look at the pic.
What have I done wrong? Why don't I arrive to the usual formula for this?

>>10845677
/pol/ tears

>>10841379
I have a ME and NE degree that i actually just graduated with. And i have set myself up for a dream career , but a part of me wants to go to grad school for computer science or mathematics. And another part of me wants to get a neurology masters and then Phd and then work on brain mapping in a real quantifiable sense.

Fuck there is so much i want to do. Right now im going to be stuck for a few years working in the nuclear industry (which is my supreme dream).

How do i quench these absurd wants and desires to do absolutely everything without jumping off a bridge.

>>10841379
I found about "Rules of definition" in a book , it talks a little bit about them but doesn't list them or anything, sucks. I couldn't find anything online, does anybody know about them ?

Defining things in set theory and logic is so different, kinda freaks me out. This is the book : "Introduction to Logic: and to the Methodology of Deductive Sciences" Page 30

https://www.amazon.com/Introduction-Logic-Methodology-Deductive-Mathematics-ebook/dp/B00DGBMGF2?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B00DGBMGF2

What differences are there between an undergrad course in biology and an undergrad course in biotechnology?

>>10849525
Get so neck deep into a field everything else seems too simple and superficial.

I'm trying to teach myself linear algebra, but I'm struggling with the fundamentals. One problem I'm having is carrying out proofs such as in pic related. Writing proofs in general is basically foreign to me, but especially so when trying to verify things that I only understand to be implicitly true. I have no sense for what makes an adequate proof -- where they should begin or where they should end. I can't skip over this stuff, even though it SEEMS kinda trivial, right? Would anyone mind suggesting some resource that might help me understand the significance and how-to of doing proofs?

t. a chemistry major

>>10849841
The canonical recommendations are Book of Proof and How to Prove It.

I however found this the most fun: https://www.amazon.com/Mathematical-Proofs-Transition-Advanced-Mathematics-ebook/dp/B07DCTQX7S/ref=sr_1_1?keywords=Mathematical+Proofs%3A+A+Transition+to+Advanced+Mathematics+%284th+Edition%29&qid=1564516503&s=books&sr=1-1

Lots of good resources here, it's likely you don't need to read a whole book, perhaps some brief lectures or lecture notes will do:
>https://www.reddit.com/r/bibliographies/comments/ajq34w/proof_techniques/

The most important part is just practicing. So maybe read some brief notes, and practice on some simple problems. Then analyze real proofs, and note where you fucked up.

>>10849841
also, try the first few chapters of spivak for sample problems

>>10849943
>>10849954
Thanks a bunch. Kind of a relief to see Chartrand's intro comment on how unfamiliar writing proofs has become at the undergrad level. Think I'll check that one out to start.

is it stupid to use a glasses prescription that's nearing 4 years old, that I got when I was 18?

I don't actually know how/where to get a new prescription

>>10841552
Who in the hell invited this weeb? There is only one true Schrodinger Neko. Prepare for bulli imposter!

>>10849553
>>10849797
Anyone?

>>10850518
As promised:
A subspace is closed under multiplication by a scalar. Assuming it contains at least one vector v, this means that it also contains [math]0v[/math], the trivial vector, also known as (0, 0, 0, ...., 0).
If it doesn't contain 0v, then it either isn't a subspace, or it's empty.

>>10849440
my dick (get it....deep lol)

>>10850565
Nevermind im retarded, this is the second time im thinking of the 'graph' of the vector field in terms of the domain instead of codomain.. so even if like f(3)=0 the graph should still cross the origin thanks bro

>>10849501
no, finish school. ESPECIALLY if you're a fucking EE you retard

>>10850012
>Kind of a relief to see Chartrand's intro comment on how unfamiliar writing proofs has become at the undergrad level
yeah, i have a couple junior level math major friends who have never even written a proof, lmao. it's retarded and why I'm deciding to relocate to a better university for my transfer

>>10850719
i don't think he's talking about quitting school. i think he means quitting work to get more time to focus on school. possibly i've misinterpreted.

>>10850012
>>10849841
huge waste of time just work through simple proofs from a set theory, algebra or calc textbook

>>10845671
>>10845857
how do get job where i can chill with monkeys and other animals in the wild

What sort of empirical proof is there for the existence of a fourth dimension (or higher dimensions)? Similarly, how would a 2D entity be able to prove the existence of a 3D world?

>really interested in astrophysics
>find mathematics quite boring and would have to learn a lot of math I didn't do in school
Is it worth it?

Can somebody tell me what's the difference between this two?

>>10850900
https://www.youtube.com/watch?v=C6kn6nXMWF0
This might help.

>>10850886
just be urself and talk with your adviser, don't take advice from strangers on 4channel

>>10850913
Nice, thanks.

>>10850912
>>10850912
Notice that 4?is not in C, because those are all odd numbers, but 4 is in D. Because 1 < 3/2 < 8 and so 2(3/2) + 1 = 4 is in D. This is because for D, a is not restricted to be an integer.

Can you then figure out what D really is?

>>10850954
So, i want to know if i understand correctly. in D only (2a+1) is restricted to be an integer but a not, right?

>>10850911
yeah, once you realize you love math it's convienent to find that you're studying it

>>10850767
oh shit, yeah. Well idk then, but I am heavily inclined to say yes so he can focus on getting good recommendations, interships and/or networking. he can work later for money than he's making now anyway.

why is formal logic so un-intuitive? At the moment I'm just drawing up truth tables like a robot but it's probably better to understand them so intuitively that it becomes instinctual

what am I doing wrong?

>>10851091
Try going slower. Space out your thoughts.

>>10851091
intiution and logic are famous for clashing. axioms start with intuition, but theorems must be developed from logic. logic is just fucking hard, but it'll get easier as you sharpen your tools and learn to use them better

I am going into my 3rd year undergrad at a decent uni with a 3.3 in my STEM major (Biochem), having fulfilled roughly half of my credit requirements so far. It took me until the end of this last semester to get my shit together. Suppose that I give a good performance from here on out (finish with ~3.7), am I still screwed? What are my prospects in pursuing a PhD? Or just finding a reasonable job in a related field after graduating?

>>10851193
>logic is just fucking hard, but it'll get easier as you sharpen your tools and learn to use them better
Any books you recommend?

>>10850914
its good advice like this that keeps me coming back to 4channel for advice. thanks anon

>>10851193
just look at pic related. Nothing makes sense at all
knights only tell the truth while knaves always lie. W and Y are knights while rest are knaves but I can't figure out why

>>10851518
eh?

>>10851520
a logic question from an introductory discrete math textbook concerning with compound statements

>>10848579
7 months

>>10851518
You can knock out Z, because if he is telling the truth then only he can be the one knight, which would contradict W. If W were a knave, then that would mean that there were more than three knights, which contradicts Z.

So you're left with U,V,W,X, and Y. U contradicts himself because that statement would only be true if he WERE a knight, so fuck him.

V,W,X,Y

X can't be telling the truth at this point, so he must be a knave

V,W,Y

If what V said were true, then at this point you would conclude that the three remaining are knights, however, V's statement contradicts Y's, so one of them must be lying, which would mean only two of the remaining could be knights, which means Y is telling the truth.

W,Y statements agree with each other.

>>10851049
You right nigga. So D is actually the set of integers from 3 to 17, while C is the set of ODD integers from 3 to 17. Catch my drift homeboy, 4, 6, 8,...,16 don’t appear in C, but in D

>>10851372
why are there so many biochem majors here, i don’t get it.. is it a popular degree?

>>10851611
meme+saturation

>>10849505
Bls resbond

>>10851091
I personally could fill truth tables with ease from the get-go. Didn't need any explanation of the rules, since those rules are what humans use every day.

You are having trouble with filling basic truth tables like "p or q", or "p implies q"?

>>10848581
No matter what your minor ends up being(I can't advise on that), you should also learn to code in your free time. Science grads who can function without preexisting software if need be are very valuable. CS minor won't necessarily teach you this.

>>10850020
>is it stupid to use a glasses prescription that's nearing 4 years old, that I got when I was 18?
Can you still see well with your glasses on?
If yes, everything is fine, if not you should probably do something.

>I don't actually know how/where to get a new prescription
The doctor, at least if your insurance will pay for it.
Else you can just go into a store, get a test and buy new glasses.

>>10841877
Study. Try to solve problems. Exercise your brain.

>>10852735
That doesn’t increase intelligence, attrition and diminishing returns set in far before mastery is achieved if the person is an idiot

What factors affect a person's tolerance for a given substance? It seems like every time I use a substance, whether it's recreational or medical, it works great the first time and never works as well again, regardless of frequency.

Would it be better to go to a big name school like Stanford or MIT for phd even if they are not #1 in the field or go to a lesser known school that is #1 in the field? I plan on going to industry and not academia if that matters

>>10853272
well what the fuck do you think, of course go to the better prog-
>industry
oh

>>10853272
>industry and not academia if that matters
How smart do you expect your boss to be?

>>10853392
i dont want to deal with kids

Is there a formula that could tell me how many 360° rotations it would take to fully screw a screw into a surface

Let's say you were presented with this 1-1/4inch screw. How many 360° turns with a screwdriver would it take until it's in?

>>10853642
It depends on the thread. There are a whole slew of different thread types. YOu need to know, specifically, the thread pitch or threads per inch (TPI). If you know that, then you will know how many "rotations" are in X inches of a screw.

>>10853642
13.

>>10841379
What math classes (beyond intro stuff like single/multivariable calculus, differential equations, linear algebra, and basic stat) would you guys recommend a CS/Math double-major take? I probably have room for like five upper-level math electives.

>>10853843
Oh, and I'm interested in CS grad school, by the way.

Biology

What do you call the classification of an organism that is basically a tube? Every organism with a mouth and butt hole is a tube under this classification. Another classification is a cup, where the organism only has a mouth.

If I want to do some physics self study, an undergrad physics curriculum for example, what kind of math should I also study to supplement it?
t. engineering sophmore who will only cover calculus, diff eq, matrix eq and linear algebra for his degree

>>10853867
that is enough for most of undergrad physics, only other thing you might need to study is partial differential equations

If you were the last one on earth, would you even have the drive to do anything? Cause we do things to please or impress other people.

>>10853912
>we do things to please or impress other people
speak for yourself

Or we at least do things out of competition. If you were a professional sprinter and everyone else in the world died, would you still continue to train even though there is no one else to compete with?

>>10853843
>>10853847
Make sure to take all the canonical math classes, imo, like complex analysis, abstract algebra, differential geometry, topology, number theory and some probability. don't slack in stats as it's going to be a very employable fall back if grad school doesn't work out.

Now, the math classes for someone who is also CS-inclined,I'd recommend numerical analysis, or some other numerical class (I'm taking numerical analysis and computational number theory). Also, mke sure to take algorithm analysis and graph theory!

How lenient are internships with student schedules? On my last interview, they said they were pretty flexible with schedules.
All of them are scheduled for M-F 8AM-5PM
, part time. This is how my current schedule looks like. Do you think I could still be hired if I work only on MW from 8-12, and then all day on Friday?

>>10854001
just email the company and ask if it is fine bro, we cannot tell you what some random company will tell you

>>10854001
that looks exactly like my school's scheduling system (which may not be specific to my school)
norcal?

>>10854045
yes

Hey, I have measured a translational error in a trajectory using a 100m, 50m and 20m delta, that means the distance between cinsecutive measurements, and I want to normalise those measurements and then fins the mean. Do I just divide by 100, 50 and 20 or is there more to it. And a further question, what kind of units do I get in the end?

Let [math] A [/math] be a [math] n \times n [/math] invertible matrix.
Consider the linear system [math] A\mathbf{x}=\mathbf{b} [/math] .
Let [math] \mathbf{x_0} :=A^{-1}\mathbf{b} [/math] be the unique solution of that system.

Now, let's add in another unknown [math] x_4 [/math] and get the new linear system whose matrix is [math] A [/math] with an extra column [math] \mathbf{c} [/math] added to the right.
We get the equation:
[math]
[A,\mathbf{c}] \begin{bmatrix}\mathbf{x}\\x_4 \end{bmatrix} = \mathbf{b} \\
A\mathbf{x} + x_4 \mathbf{c} = \mathbf{b}
[/math]

It's obvious that [math] \begin{bmatrix}\mathbf{x_0}\\0 \end{bmatrix} [/math] is a solution, but Why is it the Only solution??

>>10853933
Thanks!

>>10854520
So am I reading your question correctly that there's no extra element added to [math] \mathbf{b}[/math]? Clearly you are still working in the previous subspace. This is equivalent to adding an orthogonal axis to your system, any movement on this axis should result in a change away for the solution point.

Here's a concrete example that should be easy to visualise:

Suppose you have a simple equation [math]2x = 2[/math]. On the real number [math]\mathbb{R}^1[/math] the answer is simply [math]x = 1[/math]. Now you add an extra axis (y coordinate) and degree of freedom and you start working in the plane [math]\mathbb{R}^2[/math]. Your equation looks like [math]2x + a_1 y = 2[/math]. The only value for [math]a_1[/math] where the solution for [math]x = 1 \forall y[/math] holds is [math]a_1 = 0[/math]. In other words y is a vertical line that does not change the value of [math]x [/math].

>>10854546
Thank you. You helped a lot, but I still haven't figured it out.

So, we have:
b=a x0 (1)
ax+cy=b (2)

From (1) and (2) it follows that
ax+cy=a x0
a(x-x0) + cy = 0 (3) Which has to hold if (x,y) is a solution

If we can show that y Has to be 0, then we get that x=x0, therefore (x0,0) will be the only solution

The thing is, how do we show that y=0?

>>10854520
>>10854546
your teachers really have raped your poor supple pseud brains haven’t they?

>>10854520
Wait a minute. Wtf am I talking about. It's fucking wolfram and its commands that's wrong.

The new matrix is a linear map L: R^4-->R^3. It has rankL = dimImL = dim span(columns) = 3
The Kernel has dimension 4-3=1. Let KerL=span(u0).
(x0,0) maps to b

So, any (x0,0) + λ u0 maps to b as well.

FFS I lost like 2 hours on this bullshit.

>>10854646
wrong pic

>>10854617
What are you talking about? I self studied linear algebra asshole.

>>10846140
Software engineering is not "software development". Software engineering deals with embedded systems such as controllers etc. in manufacturing.

You might be employed as a software dev upon graduation, but that is not the point of the discipline.

What is the reason that [math] \int \:x^{-n}dx,\:n\not= 1[/math] are all nice, pretty polynomials but suddenly [math]\int \:x^{-1}dx[/math] is [math]ln\left|x\right|+C[/math], a class of function which is (seemingly to me) completely unrelated to polynomials?
Why does the pattern break?

Likewise, why is it that the derivatives of ln(x) are all polynomials?

>>10854058
well jesus, i've never seen a 7:30 am class here. in fact that makes me think our schools are different. but if they aren't, that must be a very particular class.

>>10854915
think about it this way: what's the integral of x^(-1+r) for small r>0? it's proportional to x^r. so then the integral of x^(-1) has to grow more slowly than x^r for any r.
but of course it also needs to approach infinity, cause you can bound it below by the harmonic series (which can easily be seen to diverge with the integral test)
any time you have a function which grows to infinity slower than any power of x, you should suspect the involvement of log.
if you just go purely by the (only semi-rigorous) idea that if dy/dx = 1/x^r then dx/dy = x^r, it should be clear that for r less than 1 your derivative can drop a little below your function value and "slow down" the growth, while for r=1 there is a marked change in the behavior where your derivative stays the same as your function value (so doesn't slow the growth at all). then when r > 1 your derivative will grow a hell of a lot quicker than your function value, so it will just shoot off to infinity. this change in behavior is known as bifurcation, and r = 1 is a bifurcation point here.

This guy >>10854726 just posted the full version of E=mc^2,
>E^2 = (mc^2)^2 + (pc)^2
1) am I right to assume this is third order w/ respect to "c^2", and that two dimensions correspond to mass and one to momentum?
2) What happens when a particle expands, i.e. when momentum expands two dimensionally? Does it just degenerate to the (mc^2)^2 portion?

>>10854931
Out of curiosity, what school do you go to?

>>10854962
That makes perfect sense, thanks for the in-depth explanation. I'm going to read up on bifurcation now, it seems very interesting.

>>10854734
>Software engineering is not "software development"
yes, it is - they are used interchangably and I have *never* heard of the distinction you claim exist.

>>10855033
It's really great stuff. If you want a good book which talks about bifurcations at a not-crazy level (especially the beginning) check out strogatz's nonlinear dynamics and chaos. Bifurcations are fascinating.
In general, we have a dynamical system (like a differential equation) x' = f(x, p) where f is a function of x and some parameter p. So for example x' = x^p like we had before. Then, you consider different values of p and see how this affect the solutions to your system. In our case, for some p's the solutions decayed to 0, but for other p's they blew up quickly. then there was p=1, when the system transitioned between the two sorts of behavior. then we say there's a bifurcation at p = 1, and we can talk about what happens close to the bifurcation on either side.
There are all kinds of interesting and weird bifurcations that can occur in dynamical systems. One cool one is the hopf bifurcation which happens in 2 dimensional systems. Give it a search.
I'm not sure if 3Blue1Brown's new differential equations videos covered bifurcations yet, but they certainly talk about the ideas in the first couple videos, so I'd give that a look.

>>10855015
Cal.

If photons move more slowly through dense substances than in vacuum, and photons are the carrier particle for electromagnetism, does that mean that changes in an electromagnetic field that exists within a dense medium propagate at less than the speed of light?

>>10841379
Retarded academia question. I'm several years away from graduating, while someone very close to me is graduating next year.
I've written a couple of papers that could easily get published if I had a degree, but I've not tried contacting publishers because I'm not sure if they'll simply reject them because I don't have a degree or steal and publish them under their own names.
Would it be advisable to publish them under this person I'm close with name's as soon as they graduate? Or rather, is there a better solution to this problem? I'm probably not graduating in at least seven years since I have a lot of shit in my life and don't have the time to sit down and study right now.

>>10854734
> Software engineering deals with embedded systems such as controllers etc. in manufacturing.
Wrong. That's "computer engineering", which is basically half-way between software engineering and electronic engineering. "Software engineering" and "computer science" are just different terms for the same thing.

>>10855459
that depends on whether or not you are a schizo. if not, it depends a lot on the field and the specific nature of the research. but i don't really see why you'd publish them under someone else.

>>10855460
i would argue that software engineering is the term programmers use when they want to pretend they are engineers, while computer science is the term they use when they want to pretend they are scientists. in reality, they are merely programmers.
there ARE software engineers, and there ARE computer scientists, but a lot less of them than there are mere programmers.

Can picrelated be simplified to logbase4 (y-2)?

>>10855746
No, it simplifies to [math]6 log _4 (y-2) - 5 log_4 (y+2)[/math]

>>10855758
I know, they wanted me to rewrite it as one logarithm. But can't you use exponent properties and apply the 6 to the y and the -2, then do the same with the 5 in the denominator and then use the exponent division property to simplify to just a single y?

>>10855783
No.
https://en.wikipedia.org/wiki/Freshman%27s_dream

>>10855783
w-what?
no, that's not how this works at all
anon, is (1 + 1)^2 the same as 1^2 + 1^2?

I was thinking (a*b)^x = a^x*b^x

I am a biochemistry B.S. student. If I stay an extra semester, it seems I can also double major in the Physics B.A. curriculum. I think a biochemistry/physics double major would look pretty neat, would anybody notice that the physics part is a meme B.A. degree instead of a respectable B.S?

>>10855821
sure, you're not gonna find a job anyway so may as well stay in school an extra semester

>>10855828
thanks anon

>>10855821
do you actually like physics and intend to do industry work/research in biophysics? if yes then do it. if not then don’t do it.

>>10855741
>there ARE software engineers, and there ARE computer scientists, but a lot less of them than there are mere programmers
there are also bad engineers, but they are still called engineers. retard. imo, programmer sounds cooler than """engineer""", so I give it that title. but it is, by definition, engineering.

also, it has potential to be much harder than regular engineering. gg

>>10855829
np just enjoy the ride anon I'm getting dropped off at the no-job station soon too

>>10855833
I would like to do research in either biophysics or genetics somewhere down the line. Do you think a good masters program wouldn't give a shit if I had a B.A. instead of a B.S. in physics?

>>10855839
They care about letters of recc, your actual knowledge and gre/gpa not what type of degree you got. plenty of people from math, cs and physics programs get into bio grad programs with minimal time in classes explicitly dealing with topics in biology.

>>10851091
>>10851096
>>10851193
>>10851742
For the most part I acclimated to logic way quicker than anyone else in my class, but to this day I constantly choke up when trying to apply De Morgan's to a simple conditional. Something about "p implies q" becoming "p and not q" just won't fucking click with me

>>10855820
That works, yes.
>>10855838
Me three.

>>10855842
>>10855833
Okay. I'm ringing up all my credits and I'm very very close to a math major too. B.S. in mathematics. Is that going to be just as competitive as a Physics B.A? I used to be an equal fan of both physics and math; what are some factors I should use to help me decide?

Survey: What laptops are you guys using at school/work
Field doesn't matter

>>10855877
Thinkpad T470s

>>10855877
Samsung something something.

>>10855877
some toshiba satellite with a decent amount of ram/memory, 16/1024 gigs. It's ok, does intensive shit fairly well but sometimes randomly will just crash, like once every 2 months.

Does absolute zero temperature stop time?

>>10855820
that is a product, in your problem you have sums and differences

>>10855836
you're a fucking mouthbreathing idiot. never, ever respond to one of my posts ever again.
literally ANY engineer will ALWAYS be a thousand times more competent in ANY engineering discipline than ANYONE with a bachelors in computer science. they are COMPLETELY AND UTTERLY DIFFERENT AT THEIR CORE. saying a programmer is like an engineer is like calling a cook an engineer "because they make things :)"
also, all programming is piss easy for literal children, while much of engineering is deep and requires intense mathematics and physics. i, as a pure mathematician, have a HEALTHY respect for those engineers who are competent in their field and its foundations. i have little respect for those who are not. almost all programmers have barely any competence in the foundations of computing. those who do earn my respect.

>>10855931
how do you define time? at a uniform absolute zero temperature there cannot be an increase in entropy, so in that sense, yes.

>>10855844
>Something about "p implies q" becoming "p and not q" just won't fucking click with me
Oh I think I had the same issue once.
p implies q is can be false only whenever p is true and q is false
so, p implies q is the same as Not(p and not q)
the negation of it is just p and not q.

What's the difference between hydrocortisone and hydrocortisone acetate? Are they the same or is the latter acidic?

Can anyone give me some studies on removing weed from your system?
I can't read anything off the internet that isn't cited. Mostly everyone says to stay hydrated and increase metabolism, but I need proof or actual experiments.

can i just have a clone of myself made instead of having kids

>>10856080
what if you just didn't bother with it to begin with? i think that would be smart.

>>10856085
Why even post this? No point in talking about the past, what's done is done. High-school tier shitposting.

>>10856094
>no point in talking about the past, what's done is done.
how can you be sure? >>10855850

>>10856102
I think you're high.

Since /mg/ is as shitty as usual, >>10855025

>>10856109
>is there an interesting *group theory babble*
no, purely by the nature of the field
>>10856108
that would be antithetical to my most core values

The width of a rectangular box is 2 times its length, and its height is 6in more than its length. V=101in^3

The answer is 2.445 but is there a way to do this without graphing? Use synthetic division?

>>10856125
Algebraically?
W= 2L
H= L+ 6
V= WHL

>>10855734
>i don't really see why you'd publish them under someone else.
I don't really want to wait four fucking years to publish something, but I suppose you're probably right, I should just wait or try to publish it anyway without a degree if that's a possibility.

>>10855877
macbookpro12,1 3.1ghz 8gb
debian runs like a fucking beast
despite using the same drivers, I have problems with wifi on Arch absolutely no clue why
osx 10.10 still runs well but I literally just use it to watch anime since the multi-monitor support is better.

>>10856081
Not yet. But you can soon ask for your entire genetic information to be put on.a disk.

>>10855931
If everything was at absolute zero throughout all space....and if you can get to a that temperature, then yes. As a matter of fact that is the definition of stopping time.

>>10855862
learning to think for yourself and arrange your own personal affairs, especially not bringing them onto a disgusting public arena like 4chan would probably help with most of your issues. The same would go for most of the people in these threads and on this board asking similar questions :^)

>>10841379
Is economics game theory, maths, or psychology? Why?

>>10855959
k

>t. smarter pure mathematician

>>10856386
i'm glad you agree
and yes, i am a smarter pure mathematician

>>10856391
>i'm glad you agree
if you weren't such an idiot with shit reading comprehension you'd know i don't

>>10855368
Light moves slower in a medium due to the scattering of photons off of the particles in the material. In general, EM is minimally coupled [math]d \rightarrow D = d
+ gA[/math] as a [math]U(1)[/math] gauge field such that the partition function [math]Z = \int\mathcal{D}[\psi]\exp(-\langle \psi,(D+m)\psi\rangle)[/math], and hence all physical quantities including the mass [math]m[/math] of the particle [math]\psi[/math] and the EM coupling constant [math]g[/math], receives radiative corrections to all orders in perturbation theory when [math]A[/math] isn't just a classical background field. Typically, the particles are screened by photons due to pair-creation, hence the coupling [math]g[/math] runs to a smaller values with RG flow. As the speed of light is proportional to [math]g[/math], it also renormalizes to a smaller value.
>>10855931
Inverse temperature [math]\beta = 1/T[/math] is imaginary time [math]\tau = ix_0[/math] under Wick rotation so no, zero temperature means infinite time.
>>10856109
Define interesting. You can use Ext to make group homology groups which probably does detect subgroup structures but even the second page [math]\operatorname{Ext}^{2,2}(G,\mathbb{Z}_2)[/math] is extremely hard to compute.

>>10856425
>Define interesting
I'm reading Brown's textbook on the subject, and he hasn't said much about it so far. Thus, interesting could basically mean anything here.

Can someone check if my proof makes sense logically? Also this being linear algebra, is there a more elegant way of solving this? (for e.g. I may have missed some important theorem somewhere)

>>10856425
based yukari anon

Can someone check if my proof makes sense logically? Also this being linear algebra, is there a more elegant way of solving this? (for e.g. I may have missed some important theorem somewhere)

>>10856781
>since ad - bc = 0 ...
that is literally what is to be shown, you can't just assume the conclusion anon.

you can kinda do the last two lines in reverse to actually prove the statement, and you probably have to do something special to handle the cases where you are dividing by zero

>>10856781
Also, you divided by a which you can't show is not 0, you need to account for that case.
A more elegant way would be that ad-bc is the determinant of the matrix, so if it's not 0, the matrix is invertible making it have a maximal rank (2) and the rank stays the same in the reduced echelon form.

>>10856899
My bad I'm kinda lost here. I'm self studying linear algebra before the school term starts and there's no mention of determinants up till this point.
Is there some kind of intuitive explanation/book you could recommend? I'm currently using elementary algebra by Howard Anton and am currently finding this topic mind-numbing

>>10856907
I don't think I can teach that in a few rows, you'll get there eventually if you keep up the study.
I guess it makes sense that you even do this exercise since while you didn't learn determinants otherwise it's too easy.

Anyway, i wouldn't go for the contrapositive proof and you need to split for cases in which what youre diving with is 0.

>>10856907
Use linear algebra and its applications by lax, linear algebra done right by axler, and/or linear algebra hoffman and kuntz and make sure you understand the definitions before you attempt to prove anything it will save you a lot of time.

>>10856781
[d,-b ; -c,a] . [a,b ; c,d] = (ad-bc)[1,0 ; 0,1]

What is the proof that the taylor Maclouren expansion of e^x actually converges to e^x for all x? I know that it converges for all x by some simple convergence-tests but i can't find any proof that it converges to e^x.

Any web based map where I can move a time slider to view tectonic plate movement through history?

>>10845857
Best place to buy these textbooks?

>>10857417
It's a power series that converges everywhere, and is thus complex analytic.
If you meant "define exp as exp=D exp", just compute the Taylor expansion.

>>10856781
dude just prove it directly, why are you using the contrapositive and confusing yourself
you literally prove the converse of what you're trying to show. look at your end result, it' s the RREF of the matrix.

>>10857417
e^z is holomorphic and in fact entire, therefore its taylor series converges to it everywhere by basic complex analysis.

>>10857421
Samefag here, I found https://www.gplates.org/ gonna try it out.

>>10842461
In Greece (atleast when i went to school) we get a basic understanding of them in high-school. In my physics university, first time i saw them was in a subject called Mathematical Methods for Physicists on the second half of my 2nd year. That subject was all about them

libgen is dead. Where else do I pirate textbooks and shit from?

>>10858082
libgenis not dead

>>10858082
libgen.io is dead.
libgen.is is up.
gen.lib.rus.ec is also up.

>>10857449
libgen, b-ok

What are the odds or whatever? Muh kid has a friend and there are three home rooms that they may end up in. So: kid 1, kid 2. Class: A, B, C. How many combinations are there? (In total.) I know that there will be three in which they are in the same class.

>>10859284
9.

Going through KhanAcademy for Math I find that nearly all of the questions I get wrong result from calculation errors caused by poor addition/subtraction/multiplication/division, rather than not understanding the concept being tested. Should I stop what I'm doing and just grind basic arithmetic until I stop making silly mistakes, or is it fine to keep moving forwards with different concepts so long as I understand those and just improve my arithmetic through continued use/separate practice?

>>10848581
Ooh! I don't have experience in getting a job in that area, but there's reasonably good demand for guys in bioinformatics.

I'm a math guy who doesn't really want to, but I end up doing a fair amount of biology because of the problems I work on, and I'm honestly astounded at how biologists solve modeling problems without tools like numerical analysis, finite elements methods, computer adaptive methods...

If you minored in math enough to study some proof stuff, it will be a little easier for you to pick up numerical tools that you could use and impress your friends. (my two cents...)

I guess it also depends on if you're good at/like math...

>>10857449
>buy

>>10857417
Depends on how you define e^x.
Most of the time it's actually Defined by the series [math] \sum_{n=1}^{\infty} \frac{x^i}{i!} [/math] , so the proof is trivial.

>>10860073
Exponentiation has a definition, independent of the definition of e. Specifically, x^1=x, x^(a+b)=(x^a)(x^b). It's straightforward to show that the series is invariant under differentiation. Whether it is equal to some constant raised to x is a separate question.

>>10860240
>Exponentiation has a definition, independent of the definition of e. Specifically, x^1=x, x^(a+b)=(x^a)(x^b).
That's not a definition of exponentiation.
For example, what is [math] 2^{\pi} [/math] ?
You can't define it with roots and repeated multiplication, since [math] \pi [/math] can't be expressed as a fraction.
You can do it with [math] e^x [/math] ([math] a^x:= e^{x \log(a)} [/math]), or you can do it by defining it as a the limit of [math] 3^{a_n} [/math] where [math] a_n [/math] is a sequence of rational numbers converging at [math] \pi [/math].
Then you need to show than this is well defined, i.e. if [math] a_n, b_n [/math] are rational sequences, both converging at [math] \pi [/math], then [math] 3^{a_n} [/math] and [math] 3^{b_n} [/math] converge at the same value.
Defining exponentiation, on irrationals is almost as weird as defining it on imaginary numbers. Both stray away from the notion of repeated multiplication.

>It's straightforward to show that the series is invariant under differentiation.
It is not invariant under differentiation.
The derivative of [math] a^x [/math] is [math] \log(a) a^x [/math] . Also, you can see that natural exponentiation pops up here, in the form of its inverse, the natural logarithm. ([math] \log(a)= \lim_{h \to 0} \frac{a^h-1}{h} [/math])

In any case, if you define e, say, as the limit of [math] (1+\frac{1}{n})^n [/math], and the define [math] a^x [/math] the way I described before, you are going to have a hard time, proving what you want.

>>10860240
>>10860356
Also check this thread
https://math.stackexchange.com/questions/55068/can-you-raise-a-number-to-an-irrational-exponent

>>10856114
b/r

how do you calculate the follower pressure angle for a cylindrical cam?