/sci/ - Science & Math

nigger

+ nigger

>>10172358
>>10172360
>>10172379
I fucking love math

How do you do Gaussian elimination on singular matrixes?
like the following one:

>| 2 -4|x1| -6
>|-1 2|x2| 3
Is obviously a singular matrix
Here the answer is supposed to be x1=[-3 0]^T+x2[2 1]^T
I can understand in part as the Gaussian eliminaton will result in an equation that will look like this:
>x1-2x2=-3
Thus:
>x1=[-3+2x2]
But how do I come to that answer above?

Does TEX work yet btw?

>>10172405
>those matrices
Just write them like any proper person:
(2 -4) ([math]x_1[/math]) = (-6)
|-1 2| |[math]x_2[/math]| = |3|
>inb4 why the parenthesis above and the lines below
Traditional sandwich notation.

>>10172423
this board doesn't seem to support tex anymore that's why the matrices look ass

>>10172405
>Does TEX work yet btw?
>>10172423
>>10172442
>this board doesn't seem to support tex anymore that's why the matrices look ass

Are you retarded or just a CS major?
[math]
\begin{bmatrix}
2 & -4 \\
-1 & 2
\end{bmatrix}
\begin{bmatrix}
x_{1} \\
x_{2}
\end{bmatrix}
=
\begin{bmatrix}
-6 \\ 3
\end{bmatrix}
[/math]

>>10172574
oh well, a few months ago, using [math] didn't work. so I cba to write a whole TEX format figure if it could just turn into a mess

"Hydrochloric acid, used optionally in the final reaction, and its fumes| are corrosive and also hazardous to human health."
Do I put a comma?

>>10172358
tfw brainlet

Why does isentropic compression of a gas lead to an increase in pressure?

>>10173937
"Hydrochloric acid, used optionally in the final reaction, has fumes that are corrosive and hazardous to human health."

"The Hydrochloric acid that is used optionally in the final reaction has fumes that are corrosive and hazardous to human health."

>>10174214
>In thermodynamics, an isentropic process is an idealized thermodynamic process that is both adiabatic and reversible.
>an adiabatic process is one that occurs without transfer of heat or mass of substances between a thermodynamic system and its surroundings

>PV=nRT
>n, R, T are constant
>V decreases
>therefore P increases

>>10174323
>n, R, T are constant

Ah, I've been considering when T wasn't constant. This makes more sense now

>>10174171
Anyone please? Don't want the full solution, just want to know what method is the appropriate one in this particular case.

I'm probably completely retarded, but how do they get the equality in pic related? I just don't see it

>>10174848
>ln(x)=-ln(1/x)
>[math] \frac{\sqrt{x^2+16}+x}{4}= \frac{4}{\sqrt{x^2+16}-x}[/math]

how long would it take a determined full time student to do all of this outside their curricula?

>>10175082
Depends a lot on the person. This is basically 60% of a maths major.
Unless you mean just the first part, that's two weeks.

>>10175082
First part, starting from Calc 1 and taking classes, probably 1.5-2 years. The rest included, probably 2.5-3 years?

>>10175112
>>10175102
thanks anons

>>10172358
>Suppose p is a prime that divides the order of a finite group G. Show that there exists an element of order p.

the order of each element divides |G|. i haven't got that far yet with groups but would i be wrong in guessing that there's a correspondence between the order of each element in G and |G|'s prime factorization?

>>10175160
https://en.wikipedia.org/wiki/Sylow_theorems#Theorems

>>10175082
>how long would it take a determined full time student to do all of this outside their curricula
>outside their curricula

Much of it is common to most STEM majors.

>>10175164

that makes sense. this is one of the more fun topics i've studied. there are a lot of familiar themes from linear algebra. for instance, identities like (AB)^(-1)=B^-1 A^-1 that i previously just had to take at face value make a lot more sense.

is a 'complete set of residues modulo [math] n [/math]' just a set formed by mapping each [math] x\in\mathbb{Z}/n\mathbb{Z} [/math] to one of its representatives?

>>10175361
basically, yes

>>10175361
>http://artofproblemsolving.com/wiki/index.php/Complete_residue_system

Yeah, also it never comes up again (or ever).

Suppose two differentiable functions [math]f, g[/math] on [math](0, \infty)[/math] such that [math]f'(x) = g'(x)[/math] for every [math]x > 0 [/math].

How can I prove that [math](f-g)(x)[/math] is a constant function without using the mean value theorem? As far as I know, I can't use it since I don't know whether the functions are continuous or not on [math]0[/math]

>>10176165
Use de Rham cohomology. [math]H^0((0,\infty))[/math] is the space of locally constant functions on [math](0,\infty)[/math] so it suffices to show [math]f-g \in H^0((0,\infty))[/math].

>>10172358
I'm the king of the brainlets and I was thinking about this on the crapper.
I have a visual aid for my stupid question that doesn't deserve its own thread.
But does entanglement survive the passage through an event horizon?

>>10176230
The quantum state [math]|X\rangle[/math] merges with the state [math]|\Psi\rangle[/math] of the blackhole and the quantum state [math]|Y\rangle[/math] is entangled with [math]|\Psi\rangle[/math].
Now the problem comes from the fact that blackholes evaporate via Hawking radiation. What happens if we keep feeding entangled particles into the blackhole so it evaporates away to the vacuum [math]|0\rangle[/math]? There's nothing in the [math]|0\rangle[/math] for [math]|Y\rangle[/math] outside of the event horizon to entangle with, so is the entanglement broken? If this were the case then we lose information about the entangled state [math]|Psi,Y\rangle[/math] we started with, since we now only have [math]|Y\rangle[/math]. This is the blackhole information paradox.
Here's a possible resolution https://arxiv.org/abs/1703.03042

I have separately that a) x is a subset of A and x is NOT a subset of C, and b) x is a subset of B.
I get that, if you went about it very formally, you would generalize a), then specialize with b), to conclude that x is a subset of (A union ~C), However, do I need to do any word trickery in a proof to conclude this? Can I not just say, Thus, we have that x is a subset of b and x is a subset of ~C, and go from there, or is it necessary to be more precise?

>>10176165
You force it from the definition.

>SIMPLE question and not stupid question thread

no nigger now i HAVE to post in the weeb thread. baka at least do it right if you're gonna btfo him for doing it wrong

>SIMPLE question and not stupid question thread

no nigger now i HAVE to post in the weeb thread. baka at least do it right if you're gonna btfo him for doing it wrong

>also mfw baka

>>10176165
>>10176165
is f' = g' then f'-g'=0 for all x, this is suficient to conclude that the function f-g is constant.

>>10176316
Thanks. It's going to take me a bit to read that.
Im trying to learn more about this stuff on my own beyond the popsci tier.

>>10177017
The canonical sqt poster also does it desu.

>>10176432
x is not necessarily a subset of ~C.

The fact that x is a subset of A is all you need, because A is a subset of A union anything.

Please help me with a. Do I just find Fg for each and then compare them?

>>10177274

>>10177290
Thank you!

>>10177290
Stay classy /sci/.

[math]\, \, \,[/math]▲
[math]\,[/math]▲▲
Guys, I figured out why Latex is /sci/ only. Turn on adblock or something.

Is there a compact subset of Rn with smooth boundary, such that the boundary has negative constant curvature?

>>10177567
>implying I've ever turned it off
I whitelisted back when moot was around.

Hey
Anyone know the best language for object oriented scientific programming?
Should I buy matlab? Or is c++ okay?

>>10172358
I write the putnam in 30 mins, any advic anons?

>>10176165
What is wrong with the mean value theorem exactly ? Just fix a point, say 1, and apply the mean value theorem between 1 and x for each x > 0. The function will be continuous on the closed interval and differentiable in the interior

>>10179756
Matlab isn't oop, scientific programming is usually procedural.

>>10179756
C++17

Is there anywhere I can find data dumps from simple experiments (bachelor level stuff) or programs to simulate them? I'm talking RLC circuits, damped oscillators etc.