/sci/ - Science & Math

Dear OP,

Kindly remove yourself from the premise.

Best regards,
Anon

>>7137414
>not "p prime"

>>7137407

Prove: The solutions to the differential equation 9(y'')^2y''''' - 45y''y'''y'''' + 40(y''')^3 = 0 are precisely the non-degenerate conic sections.

>>7137407
>400-ft-tall
Fuck off

>that wasted potential

>>7137414
Assume not, √p=p/q for some p,q with GCD(p,q)=1
then p=pp/qq and qqp=pp so qq=p but then p∣q and GCD(p,q)≠1∎

>>7137488
> Assuming smart people show you everything they can do all the time and not keep some to themselves.

>>7137407
Can someone explain to me why everyone is shitting on OP?

Is the image totally B.S. or?

Q: what two organelles in eukaryotic cells have a genome that differs from that of the DNA in the nucleous?

A: Mitochondria and Chloroplasts

>>7137615
Wow, you memorized that piece of trivia about cells? You must be so smart.

>>7137490
Did you even read the question?

>>7137627
I bet he's wearing Hawaii shirts and flipflops at home and could not care less what you think.

>non-SI units
>only math
Kill yourself, OP.

What is the key intermediate and what three products form?

No pure mathematics allowed.

>>7137672
>>non-SI units
only a babby student would complain about this. In upper level physics SI isn't even used that much

should be able to do all these

>>7137792
cgs master race

prove that f(x)=\begin{cases}1/q & x = p/q in lowest terms\\0 & otherwise \end{cases}

is integrable over [0,1]

>>7137936

this is what i meant

>>7137407
uhhh, i'm not gonna work with foots and shit..

also
>only math
lol

>>7137949
You can't just write the integral like that without specifying which measure you're integrating with respect to.

>>7137994
A U T I S M
U T I S M A
T I S M A U
I S M A U T
S M A U T I
M A U T I S

>>7137407
4.(2)(a)
how the fuck do you solve that transcendental equation?
lambda^2 - 2*lambda*cos(theta) + 1 = 0

Guy where did that transcendental question go were you doing a LinAlg question get back here

>>7138010
I realized that the variable wasnt theta
really embarrassing

Andrew performed a microarray experiment and wanted to find out which genes were the most stably expressed in his samples. He calculated a coefficient of variation for each gene. Why was this a bad idea?

>>7137936
>>7137949
>1/q

Please, you could do that day 1 in calc one.

>>7137994

If it's not specified, I'd assume he means with respect to Lebesgue measure.

>>7137407
Is tan(1°) rational? (prove your answer)

>>7138262
tan1 / 1
it is a fraction
it is rational
QED

>>7138267
It's still shitposting, even if you're being ironic.

>>7137994
You'd have an aneurism on a physics class.

>>7138393
in physics class we always wrote the differential term...

>>7138269
>It's still shitposting, even if you're being ironic.
That confirms his admission on /sci/

>>7138262
Yes, it has a Taylor series.

>hurr durr durr

I'd rather see "write one combinatorial proof and one proof by induction" rather than the vector calculus.

>>7139169

>>7139166
How does that make it rational?

This should be rudimentary enough.

>>7139186
Uh... Stoke's theorem?

you know it's called /sci/ - Science & Math not /sci/ - Math

>>7139196
Chern-Simons conformal field theory.

>>7137407
>2015
>inches

go fuck yourself

>>7139198
you should know this stuff even if you studied engineering.

>>7139205
Ah. I saw Ed Witten give a talk if that counts.

>>7137897
most of these are actually solid choices

>>7139176
I like this a lot more than OP.

>>7139176

Solutions please

Use spectral sequences to show that the De Rham cohomology of a differential manifold is the same as the Cech cohomology.

>>7139232

>he thinks math is science

>>7139219
That should count for something. The Wess-Zumino-Witten conformal theory is mainly my object of study.

>>7139236
Thanks my nigga

>>7139236
I'd kill the person who wrote that.

>>7139219
Yesterday?

>cubic yards
>miles
My poor eyes

What about biology majors?
http://biology.mcgill.ca/undergrad/majorprog.html

>>7139250
>>>/an/

>>7139213
>being bullhurt over units
>>being autistic

>>7137407
Prove that for any compact simple gauge group G, a non-trivial quantum Yang–Mills theory exists on {R}^4 and has a mass gap Δ > 0

>board is called /sci/ - Science and Math
>test is all maths

Can math majors even into science?

>>7139310

>>7139302
I'll be working on this and claiming my millions dollars.

>>7139244

Agreed.
Just stfu and do the math.

>>7139310
Mathematics is the language of scientists.

It's the most neutral test possible. We certainly are not going to make a specialized test on how well you know NodeJS or commercial aircraft design... There is a reason why the GRE is about languages: English and Maths.

Math spergs are so retarded its awesome
Gotta pay sports players millions a year just to consider playing for your team but thousands of spergs will all work on your problem for decades where only the winner claims a paltry $1m

>>7137585
It's all pretty easy stuff; anyone who graduated with an applied science or mathematics degree should be able to solve all of them relatively simply.

>no triple integrals
>no Barnett's identity
>no 1+2+3+...=-1/12

>>7137585
Cause I have a bachelors in CS and I can answer all those questions. So obviously these should be trivial for any math/physics major.

>>7137407
>go to /sci/
>read threads on noble pursuit of pure knowledge, and humanity's duty in doing so
>come across thread toting some exclusionary "test" to keep out the undesirables, country-club style
>yeah, high IQs should rule the world all right. Then everything would be fine.
>stay classy, /sci/

>>7139498
Someone is butthurt that they can't pass a simple test

>>7139503
Someone doesn't realize /sci/ can only exist for one of two reasons:
>facilitate communication efficiently amongst as many participants as possible
or
>engage in tribal behavior (i.e. identity politics and exclusion)

>>7139498
Popsci fans don't belong here.

Leave.

>>7139514
you guys should make up some memes and start repeating them to each other like /tv/ does. Then when people don't "get it", you can all giggle to one another. That would be cool.

>>7139517
Sir, <span class="math">\frac{a+b^n}{n}=x[/spoiler], hence God exists—reply!

>>7139508
>engage in tribal behaviour (i.e. identity politics and exclusion)
You say that like its a bad thing
Tribal politics is the most complex phenomenon in existence

Describe a function that is continuous at 0 but not continuous at any other point

>>7139688
In real numbers

>>7139688
are you blind? >>7137949

>>7139166
so does f(x)=x
its taylor series is as follows:
x

>Not a single question about statistics
>Not a single question about common knowledge in sci
>Nothing about waves, optics, chem, geology or others
>All pure mat

Yeah, pure mathematicians are the leading force on science

captcha: how ilaryiu

>>7137407

>1 (2)
>please include units
>feet

>FEET

>>7139782
well math is the only thing math physics and engineering have in common
i don't think chem and bio learn this much math though

honestly if you just look into the probability thread you'd weep for /sci/ since it is abundantly clear that at least 50% of /sci/ has absolutely no understanding of even the simplest concepts

>>7139783
Bring back the shilling.

Prove that 0!=1

>>7140304
1!/1=0!=1

>>7140307
no you stupid fucking faggot

>>7140310
why not, you idiot

>>7138239

its reimmann integrable as well

>>7138236

"no" actually you literally can't do it in calc 1

>>7138393
I have literally never seen, not even once, that a teacher forgets the d(...)

>>7139688
Doesn't this have a trivial solution?

>>7140344
>>7138393
>>7137994
All these niggas need a course in operator theory. You don't even understand what the integral symbol and the differential are. Are you engineers?

Should have different versions, not just a math/physics exam. As a med student I am a future member of high society along with you and the rest of /sci/, so a questionnaire for me would ask about physiology for example, or how many bones there are in the body.

>>7140364
sure am
and i don't want your "rigorous" nonsense either, I do my calculations just fine

>>7137585
or what nigga?
fucking finish your sentence to get a decent response. stop going around and ending your statement with a "or.." Or what!

>>7137417
>i am a pedant

>>7139496
Well I have a masters degree in physics and i have never heard of the mean value theorem before. It's just not relevant to...hmm...all physics I have ever studied.
So there is a question I couldn't answer.

>>7140682
>masters degree in physics
>never heard of the mean value theorem
>that's literally not possible, since you have to take basic as fuck calc 1

>>7140685
>Still remembering shit you learned in calc I
How's calc IV treating ya?

>>7140692
>calc IV
literally not a class at good unis, only cc bullshit

>>7140685
Masters degree from UK, so I never took "calc 1" as you call it. Also the name is important, the mean value theorem never heard of it before this thread, yet I most definitely had calculus lectures and have a physics degree. Not really sure how that is impossible.

>>7139166
f(x)=e^x also has a taylor series but that doesnt make all values of f(x) rational you dumb fuck

>>7139186
what field does this question belong to?

>>7139166
All continuous functions have a Taylor series...

>>7140695
>UK
oh nm, you basically have a high school equivalent education

>>7139316
SICK PARROT MAY MAY XD

>>7137407
So far this thread seems to be just maths.
Maths is not all science.
Someone tell me the acceptable level of vibration on your optical bench if you want a michelson style interferometer to obtain a resolution of 0.075 wavenumbers with perfect parabolic focusing mirrors used in your interferometer and an aperture size of 1 mm^2?

'cause that is some basic shit right there, but good luck with even a single one of you faggots being able to tell me an answer.
I'd even be impressed with a reasonable estimate...

>>7140714
>So far this thread seems to be just maths.
these are all science >>7137897 apart from the meme integral

>>7140704
Derive me the noether charge for the langrarian:
L=1/2 ∂_μ ψ ∂^μψ−1/2 m^2ψ^2

where _ indicates subscript and ^ is super

>>7140716
Ok fair point, my point was that while maths may very well be the language of science, most science is not just a series of undergrad exam questions...

>>7137897
can someone explain the spacecraft question

>>7139458
>certainly are not going to make a specialized test on how well you know NodeJS or commercial aircraft design... There is a reason why the GRE is about languages: English and Maths.

What the fuck is a GRE? ah I see, US bias comes through again!
>toot toot all aboard the freedom train lads!

Derive Einstein's Field Equations from the E-H action principle

>>7140721
answer mine and I'll do yours

>>7140694
Literally just another name for ODEs

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

>>7140476
No bully please and try to understand.

>Btw I think you shouldn't take a test about science but you should be tested in the will of understanding.

Whatever, he might be german, and germans use 'or' to construct a rhetorical device, called "Ellipse', so don't judge him.

>>7140765
no

>>7140733
hint: use boltzmann thermal relation

>>7140801
oh thank god, it was not doable with anything i have learned :D

>>7140740
Jesus I have no fucking idea how to do this.
So you can use stats of a gas to link temperature of electrons to their speed, use some equipartitions assumptions to rrealte ion and electron energies.
But how do you obtain a relation for a spacecraft?
surely you need the crafts speed, its hulls capacitance?

>>7140851
voltage is the important factor
capacitance determines the charge

>>7140851
J = nev

>>7140876
i know that formula, it is not enough to approach that problem, someone already said boltzman stuff, which i have no knowledge of

>>7139250
>mcgill
mein negro

>>7140876
>>7140872
>>7140740
>>7137897

I'm going to have to say, I can't solve this.
Even looking up this Boltzmann thermal relation (never studied plasma physics so had to google fu what the hell this is)
I don't get it.
Your question is in the form of a prove this is of this form..
So you give the answer, from which it is clear its just the natural log of the Boltzman relation with some electron density terms replaced with terms with Ve and Vi in, but I don't see how you obtain those terms from ne (V) and ne(0)

>>7140740
i remember this question being posted over a year ago, i couldn't solve it then, can't solve it now

>>7140911
>ne (V) and ne(0)
the v there in J = nev is velocity, not potential, its current density

>>7140922
Yes, that much is clear.
But the V in ne(V) is a voltage.

>>7140333
There's only φ(p) points with value 1/p so you can break up the integral into finite number of them and bound it above by an arbitrary value. Thus it's clearly zero.

>>7140924
no it is drift velocity

>>7140703
http://en.wikipedia.org/wiki/Weierstrass_function

>>7140927
Were are miscommunicating here.
I am saying that n subscript{e} function of (V) has V as a voltage, you are saying that nev has V as a drift velocity.

>>7140466
>As a med student I am a future member of high society

No.

>>7140936
>http://en.wikipedia.org/wiki/Weierstrass_function
Mind blown.
Now if you'll excuse me, I have a kissing date with a shotgun barrel.

>>7138003
ooo....a burrows wheeler transform...

>>7140940
well he'll be wealthier than most STEM fags

>>7140682
>Well I have a masters degree in physics
>never took a Taylor series

Yeah, no. Watching Black Science Man doesn't give you a MS in Physics

>>7140768
Yes.

Calc4, ODEs, and DEs I are all the same course. Also your course numbers aren't universal.

>>7140938
what is the n_e function

>>7140948
I never said I didn't know what a taylor series was.
I did say I never heard of the "mean value theorem"

>>7140958
its in the boltzman plasma relation
http://en.wikipedia.org/wiki/Boltzmann_relation>

>>7140960
Why is Ni = Ne exp(eV/KT_e)?
I thought it was Ne at potential V = Ne at potential 0 * exp(...)

>>7137407
The vector calculus section is bullshit. That's just multivariable calculus. Some appropriate questions would be:

Proof that <span class="math">\nabla\times\nabla\times=\nabla (\nabla\cdot )-\Delta[/spoiler]

Proof Green's theorem.

>>7140975
proving greens theorem is much much harder than the other

>>7140960
>that exponential
I remember the diode equation having an exp(V_thermal/someshit) what is that exponential term

>>7140984
you see it a lot in stuff like photovoltaics/solid state stuff and thermionic emission

>>7140984
http://en.wikipedia.org/wiki/Boltzmann_relation

I don't think so. Proving Stokes' or Gauss's would be hard. I proved Green's on my own without looking in my book/going to the lecture.

>>7140978
I don't think so. Proving Stokes' or Gauss's would be hard. I proved Green's on my own without looking in my book/going to the lecture.

>>7140996
>Green's theorem
My bad had a retard moment and read greens theorem while my brain inserted stokes theorem.

>>7140975
for the vector identity you just use a dummy scalar field?
greens theo is much more difficult

>>7137407
>integral calculus
>not having laplace transform or beta/gamma function related questions
Those are highschool questions OP. Considering this is an 18+ board, you should at least put some harder stuff.

>>7141006
A dummy vector field, notice the rotation. It's a bit abuse of notation though, the Laplacian only works for scalar fields, but you can define it for a vector field as <span class="math">\Delta F=(\Delta F_1,\Delta F_2,\Delta F_3)[/spoiler]

>>7141014
>Laplacian only works for scalar fields
wrong

>>7140994
So basically stuff involving electrons

>>7141019
Care to explain why you disagree?
In most courses the Laplacian is only defined for scalar fields. As I explained you can do it also for vector fields. Some people consider it abuse of notation (I don't, but I see why some people find it confusing).

>>7141026
gradient of a vector field (rank 1 tensor) is rank 2 tensor
divergence of rank 2 tensor is rank 1 tensor (vector field)
you can have your way with all the vector gradients if you are in cartesian coordinates

>>7141031
That brings us to tensor analysis/tensor algebra. All good but that's a bit far-fetched imo since we're talking about simple vector calculus. Anon in No.7141006 thought the identity was about scalar fields, I assumed he was confused because of the Laplacian so I gave some extra information about it.

>>7141047
well the existence of that vector identity acknowledges that the laplacian of vector fields exists

>>7141051
yes :)

Sketch the procedure by which the transitions on the flowchart can be realized.

>>7140714
>Maths is not all science.

4chan is for people over the age of 18. Go find a children's forum to discuss your popsci crap.

>>7141099
see, this is what people don't get
OP makes sense because those shit are something all math phys and eng folks can do
when you ask something so area specific, it doesnt apply to the mass of /sci/

do you think that more than half of sci can even find the range of a ball thrown with an angle
i'd wager not
half of sci has no understanding of conditional probability either

we don't need fancy problems

>>7140943

Residents make less money than burger flippers. Medicine sucks.

>>7140963
Same shit.

>>7141106
Is supposed to be tongue in cheek. There would probably be less than 100 people in the world who can answer that.
I guess you aren't the perceptive type.

>>7141112
>Residents
what the fuck is "resident"
also i am pretty sure doctors make incomparably more than any stem can make in america

>>7141106
>range of a ball thrown with an angle
How would you do this

just curious

>>7141125
if you throw with angle a and speed v
sina*v is vertical component
cosa*v is horizontal component
sina*v/g is the time it takes to reach the highest point
2sina*v/g is the time it takes to reach the top and come back down
in that duration, it will travel horizontally at constant speed cosa*v
so 2sina*cosa*v or sin2a*v
therefore, for level surface, it is best if you throw at 45 degrees

>>7141118
>https://en.wiktionary.org/wiki/resident#English
>A graduated medical student who is receiving advanced training in a specialty.
>> She's a resident in neurosurgery at Mass General.

>>7141139
umm, so what, it doesnt take forever to be specialized eventually

it ought to be better than being professors fuckboys

Mind fucking combinatorics.

Inventory numbers have been created so that typing them on the top row of a computer keyboard requires either a left-right-left or right-left-right pattern. Each inventory number uses only digits 1 through 9 with no repetition.

How many inventory numbers are there?

*Note
left-right-left:
a < b, b > c, a != c

right-left-right:
a > b, b < c, a != c

>>7141106
Ooooooo I just had a probability and statistics final. Please give some conditional probability problems.

>>7141229
Introduction-to-Probability-2e-by-Dimitri-P-Bertsekas-John-N-Tsitsiklis.pdf

prob-solved_2ndedition.pdf

google for these, great examples

>>7141151
5 years being paid shit + 2 years specialty school loans collecting interest + 2 years med school loans collecting interest + 4 years of college loans collecting interest = You're broke as fuck until your 40s.

>>7141257
>college loans
AHAHAHAHAH
>not being born to a wealthy family
lol it is hilarious that so many people get this part wrong
you just check the correct box prior to being born

>>7141273
Still no money until you're 18+4+4+5=31

>>7141185
This covers the math portion. What about the physics?

>>7137407
Reminder that if you cant solve pic related (babby level field theory exercise) you don't deserve to be on this board.

>>7141435
<div class="math">\mathbb{Q}(\pi^n)</div>

?

>>7141435
Q[[pi]]

Math is the only one of STEM which all fields use, so it makes sense that the test would be only or mostly math. Though, I do think that English questions should be added, even though it's not STEM, it's still integral to this board. What do you guys think?

Grammar and syntax are good subjects for questions.

>>7141435
yes you will get responses but remember this is /sci/ - Science & Math so science should come first logically...

Calc 1 student here
Is the answer to question 2 in the first section 346 ft/s?

Also roughly put, the mean value theorem states that is f is continuous and differentiable on the interval [a,b] then there exist a c such that the average rate of change and the derrivative at an x value =c
Correct?

>>7137407
>feet
>yards
are you fucking kiding me

>>7141529

>346 ft/s
I mean /hour lol

>>7137792
dude what the fuck

>>7141536
> parsecs
> AU
> eV
> ly
> etc

>>7141461
> even though it's not STEM, it's still integral to this board. What do you guys think?

8th grade English is good enough. Also known as English 101 in college.

>>7137407
dont waste our time

>>7137407
>all this math

B-Biologists are scientists too, r-right guys?

>>7137407
>be in Calculus II at a community college
>don't know how to do any of these

Good thing I'm an engineer.

>>7141538
sorry, I misinterpreted your post

>>7141456
close, its <span class="math"> \mathbb{Q} ( \pi ) [x] [/spoiler]

>>7141562
I mean <span class="math"> \pi ^n [/spoiler] of course

>>7141549
Don't get discouraged it really doesn't matter.

>>7141549
You're in calc II but you don't know the Median Value Theorem?

>>7141549
I'm in calc II at a community college as well but I'm >>7141435 so you don't really have an excuse. I self study and do research with one of the professors here as a freshman.

>>7141562
Neah I'm pretty sure he was right.

>>7141549

Yeah don't worry about it. As someone working in industry, there are definitely some basic things you should remember, but not even close to what's being posted here. I just seem to have a terrible memory. I aced ODE's and I don't even remember how to solve a general differential equation anymore.

>>7141566

He probably does, but completely forgot about it.

>>7141548
Was it worth it?

>>7141576
No <span class="math"> \pi [/spoiler] is algebraic over <span class="math"> \mathbb{Q} [/spoiler] so <span class="math"> \mathbb{Q} (\pi ^n) [/spoiler] has order 0 for <span class="math"> \pi [/spoiler].
When you do a second extension to <span class="math"> \mathbb{Q} (\pi ^n) [x] [/spoiler] you can actually construct an nth degree polynomial which is the lowest order monic which <span class="math"> \pi [/spoiler] is a solution to:
<span class="math"> x^n -\pi ^n [/spoiler]
There is no way to get finite order for a transcendental number c using <span class="math"> \mathbb{Q} (c) [/spoiler] for any field <span class="math"> \mathbb{Q} [/spoiler] which c is transcendental over. You have to do the iterated extension I listed previously.

>>7141663
><span class="math">\pi[/spoiler] is algebraic over <span class="math">\mathbb{Q}[/spoiler]

Are you fucking serious?

Here's another extremely simple one.

>>7141461
>What do you guys think?

Nah, just make The Elements of Style required reading.

>>7141548

No.

>>7141663
fuck i mean <span class="math"> \pi [/spoiler] is transcendental

>>7141669
see

>>7141697

Im like really fucking tired right now. What I said was correct just wrong word