Curio

general recent conversations

$Mathematics$ Mathematics

Associated with Math.SE; for both general discussion & math qu...

Curio

Nov 24, 2024 10:55

Could anyone be so kind to explain me how to reach the final expression in here?

https://math.stackexchange.com/questions/4059325/how-to-understand-the-reduced-cost-in-simplex-method#:~:text=This%20has%20a,).

In pariticular, I'm referring to "We might as well extend the variable component to..."
Thanks in advance!

Curio

Apr 13, 2024 18:22

@Jakobian They're "easy" integrals, i.e. for computing the momentum of inertia of some objects. So I think we don't have any kind of problem

Curio

Apr 13, 2024 17:27

Is it true for linearity?

Curio

Apr 13, 2024 17:27

Is it always true that the integral over a surface omega of f(x,y) + g(x,y) is always the integral over omega of f(x,y) PLUS the integral over omega of g(x,y)?
Regardless of the extreme of integrations

Curio

Feb 20, 2024 18:58

@TedShifrin Yes, your hint put me on the right path, thank you so much

Curio

Feb 20, 2024 17:12

Do you mean PP'C?

Curio

Feb 20, 2024 17:11

What is the proof for alpha + dAlpha in the picture above?

Curio

Feb 20, 2024 17:11

Curio

Feb 20, 2024 16:30

I mean, it's ds but s = s(t)

Curio

Feb 20, 2024 16:29

@Jakobian What do you mean?

Curio

Feb 20, 2024 16:28

Most of all I need to understand it, as he always uses leibnitz notation

Curio

Feb 20, 2024 16:28

Well, it's the one used by the professor

Curio

Feb 20, 2024 16:27

I'm having a bad time switching from f'(x) to leibnitz notation for differentation.
For example to solve (d/dt)(dP(s(t))/ds(t)) I need to switch to the f'(x) notation, otherwise I don't know how to apply the chain rule here. It sounds really odd, but that's it

Curio

Jun 7, 2023 08:28

What is the laplace transform of x(t)*step(t)? Is it X(s)/s ?

Curio

Jun 2, 2023 12:48

<<The unbiased sample variance is an unbiased estimator of the variance EVEN when mean is unknown>>
Of course it is when mean is unknown...but what if mean is known?
For "unbiased sample variance" I mean the first estimator in this answer: https://stats.stackexchange.com/a/162844

Curio

May 21, 2023 08:41

if (X1, Y1) and (X2, Y2) are indepedent random vectors, is it true that X1 and X2 are independent and Y1 and Y2 are independent?

Curio

Apr 14, 2023 14:03

@shintuku Thank you for your responses. Could we state that f(X) is absolutely continuous if X is absolutely continuous? Or that f(X) is discrete if X is discrete? Or that X is discrete if f(X) is discrete? Or that X is absolutely continuous if f(X) is absolutely continuous?

Curio

Apr 14, 2023 07:13

@shintuku How do the questions change if the image of X is a probability space?

Curio

Apr 13, 2023 16:39

@shintuku A generic function

Curio

Apr 13, 2023 16:27

If X is a discrete random variable, is f(X) a discrete random variable?
And viceversa?

If X is an absolutely continuous random variable, is f(X) an absolutely continuous random variable?
And viceversa?

Curio

Apr 10, 2023 15:50

Ok I found a way for the second problem, but I'm still confused about why cov(X,Y)=-1

Curio

Apr 10, 2023 15:39

And why 0.2*(2Y-X)^2 is a chi squared distribution with 1 degree of freedom

Curio

Apr 10, 2023 15:37

I'm wondering why the answer is -1 according to the solution :/

Curio

Apr 10, 2023 15:31

X and Y are 2 random variables that are not necessarily independent. Both have standard normal distribution. Can you evaluate Cov(X,Y) without knowing anything else?

Curio

Apr 8, 2023 17:21

How do you obtain the first blue dot in this slide?

Curio

Apr 8, 2023 17:21

Curio

Feb 23, 2023 16:40

John put 26 right and 26 left socks in a drawer belonging to 26 equal pairs. In the dark he draws 26 random socks from the drawer.
Determine the probability that he succeeds in forming thirteen pairs

My attempt:
1) All possible cases: all strings composed by 26 digits. These digits can be 0 or 1. So we have 2^26 cases.
2) Right cases: all strings with exactly 13 "1" and 13 "0". So we have 26! / (13! * 13!) cases.

Where is the mistake?

Electrical Engineering

A place to talk with friends from the EE community about vacuu...

Curio

Dec 7, 2023 11:25

I obtain G(s) = 1/(1-s/GBWP)

Curio

Dec 7, 2023 11:24

Let's consider an opamp voltage follower like the one in the photo: https://electronics.stackexchange.com/questions/593953/how-does-this-op-amp-config-work-as-a-voltage-follower
Is it correct to say that the opamp is instable if we switch the + and - terminals? I obtain that the transfer function has a positive pole (assuming A(s) = GBWP/s).

Curio

Oct 5, 2023 13:45

Same thing when V_gate = V_dd

Curio

Oct 5, 2023 13:43

I have a question about nMos transistors. According to what my professor says, if the potential of the gate of an NMOS is zero, then the NMOS is off. But I know that an NMOS is off just when V_gate - V_source < V_threashold. Hence, if V_source is negative, then the NMOS could be on even if V_gate = 0.

English Language & Usage: Multi-Layer…

Not for the faint of heart or those easily triggered by Englis...

Curio

Sep 6, 2023 15:39

Guys, I'm writing some lines for my game, but as a non-native speaker, I don't know if they sound natural or weird. Would you give me a hand? I'll be really grateful to you. Many thanks for considering my request.
Here are the lines:
"It’s such a joy for me to find you here. You are the only being on Earth who decided to attend this Gay Pride at the North Pole. What a devotion. What respect towards the LGBT+ community. What an activist you are. I’m so impressed. But above all… I’m really surprised! I didn’t know you were gay!"

Curio

Sep 3, 2023 08:40

Thanks!

Curio

Sep 3, 2023 08:33

The funniest one?

Curio

Sep 3, 2023 08:33

LOL

Curio

Sep 3, 2023 08:25

Hi, I'm trying to choose the most suitable sentence for my game, but I'm struggling to take this decision. Could you help me, please?

You eat a whole Pie. But your immune defense is so low that you gain 0 HP
You devour an entire pie, but with your weakened immune defenses, it doesn't restore any HP.
You consume a whole pie, but due to your compromised immune system, it fails to replenish any HP.
You consume a whole pie, but due to your severely weakened immune system, you don't regain any HP.

Curio

Jun 30, 2023 15:55

What does this sentence mean?

Curio

Jun 30, 2023 15:55

<<All those journals I filled with an eye towards stand-up comedy...but you were telling the truth!>>

Ten fold

CrossValidated's general room for gossip, grumbles, and idle c...

Curio

Jun 3, 2023 08:38

Is it true that the power of a test is always an increasing function or always a decreasing function?

Computer Science

General discussion for cs.stackexchange.com

Curio

Mar 23, 2023 17:48

Consider this function: g(x) = 1 if you can find x 5 in a row in the decimal expansion of pi. Otherwise, g(x) = 0.
Is g semi-decidable? If I'm able to find x 5 in a row, then g returns 1, but we'll never know if it returns 0, so in my opinion g is semi-decidable. Is it correct?

Game Development

Game development and other polite discussion. Game development...

Curio

Feb 16, 2023 10:44

Hi all, I have a question about audio import settings.
According to what I read, it's obvious that Compressed In Memory / Vorbis is the best set for music files. On the other hand, I don't know what to do with all the other sounds. These sounds are lines of dialogue and they all last between 1 and 3 seconds. There is never an audio that I need to play twice, because they are all part of dialogues. Moreover, I wanted to optimize the game for my pc (because I need to record a gameplay of the game on my pc, then the frame rate must be as high as possible). Here are the main specs:

Curio

Feb 12, 2023 15:14

Thank you for your super detailed answer :)

Curio

Feb 12, 2023 08:45

I'm wondering if it's good practice to use "static" in this way:
I have some classes that need to be called in a lot of scripts. For example, I have a DialogueManager that makes appear dialogues on the screen. So I just have to write DialogueManager.instance.MyFunction();, where instance is a static variable, whereas MyFunction is a non-static function of DialogueManager. I used the same approach for MouseCursor and in general for every one-instance gameobjects in my scene. Is that correct?

Curio

Feb 10, 2023 16:18

I mean, there is no node graph in Unity for materials, unlike Unreal

Curio

Feb 10, 2023 16:18

Basically, there is no direct way to convert a Blender material (the one you edit with the node graph) to a Unity material, right?

Curio

Feb 10, 2023 16:11

Exactly what I was asking, thanks!

Curio

Feb 10, 2023 15:12

I mean, in Blender I can clearly see that S stands for Specular, N for roughness,... but I can't find the equivalent link in Unity

Curio

Feb 10, 2023 15:07

I have a texture ending with "D", which stands for diffuse (maybe). However, in the material tab I don't know where to put this texture. I mean, textures ending with N match the normal map checkbox and so on.

Curio

Feb 10, 2023 14:11

Found them! They had unusual names. Thank you!

Curio

Feb 10, 2023 14:00

Hi guys, I have a question for you. (Unity)
I wanted to import a 3d model into my project. It's a .blend file + a folder with all the textures. Fine. I imported both the .blend file and the textures and it seemed fine at the beginning. But then I noticed a small problem: some materials are missing and appear completely white in my scene. Well, maybe "missing" is not the most suitable word because I had those materials, but they didn't have the base map texture. I checked the Textures folder to add them manually, but I did not find them. Here comes the crazy part. If I open the .blend file i…