Stupid Questions Thread

>>8032038
Your compiler is GHC, GHCi is an interactive environment to load and execute haskell code (primarily used for debugging and to help understand your code).
If you want to have syntax highlighting within ghci, I don't think that's possible.
If you just want haskell syntax highlighting in your text editor, it depends on your text editor how you do that. Most good ones do that by default though

>>8032044
Thanks for the answer.
I am using Notepad++ as a text editor which fortunately does have syntax highlighting.
Apparently, highlighting within ghci is possible, see http://learnyouahaskell.com/starting-out

Do you think it's necessary to get a good grasp of the language?

how big of a deal is GPA as a Computer Science major? Specifically in elective or non-major related courses? Accounting has just fucked my shit up.

>>8032055
My CS department has a minimum gpa requirement of 2.5 before they drop you from the major. That's always seemed lenient to me.

Good question OP. I wanted the same when I started with haskell. I think emacs and vi may have haskell highlight, but I didn't want to learn these bigger tools for it.
I ended up installing textwrangler as editor, but its haskell highlighting is actually quite bad and I don"t recommend it.

Btw., the freenode irc channels on haskell are good, go there

>>8032055
If you want to get hired you want your GPA as high as possible. Too low and you just get filtered out. Even though CS is a pretty modern field and some companies don't give a shot about your degree as long as you can do their work, GPA is still a measurement of the overall quality of your work as a student.

If you want to go to graduate school, you need a high GPA.

If you want to transfer into a good CS or engineering program, you need a high GPA.

You can't really game the system because bigger is always better.

>>8032084
It's the same for my school.

>>8032106
I have an extremely high GPA in the these courses. Like 3.85. However, I've gotten a B in a history course and looks like a C in accounting. Would trying to differentiate that on a resume really make much sense or would it just come off as sort of dumb?

>>8032052
>http://learnyouahaskell.com/starting-out
Not sure, I think it's just the website, not ghci itself.
I don't think it's necessary, most stuff you type into ghci will be short and readable anyway.
Of course having it would be nice, but you can do without it.

Can something be very dense but also not very heavy? My first guess is no but I am probably wrong.

>>8032373
If you speak of atom density (or, since the strong forces keeping atoms together are short range: volume dentity), then at the same density, using Helium will give you a lighter collection than using Uranium.

In the unlikely case you speak of proton density, then no.

This isn't the stupid questions thread btw.

>>8032331
Thanks a lot!

>>8032446
When you finish it, be sure to follow along with Real World Haskell.
>http://book.realworldhaskell.org/read/why-functional-programming-why-haskell.html

Do I have to eventually pay back IEHP insurance? I'm 27 years old and was wondering if I should apply to get health coverage.

>>8032052
>Do you think it's necessary to get a good grasp of the language?
Yes

>>8032446
>>8033553

There is a new book (being written, but you can buy it in advance and get chapters), that's supposed to blow all others out of the water

http://haskellbook.com/

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/sci/, I have these red spots on my crotch. Should I be worried/

How does proving the base case(mathematical induction) imply that the cases for the succeeding elements will also be true?

>>8034502
Bretty Normal, just give them a few days to improve before you worry

>>8034502
Do they become whiteheads? If so then not really. If they don't then maybe.

Should I take modafinil while I'm taking isotretinoin 20mg/day?
(this is for you, med/biofags, or anyone who has experience)

Is the inverse Laplace transform linear in the sense of [math]\mathscr{L}^{-1}(af(s)+bg(s)) = a\mathscr{L}^{-1}(f(s))+b\mathscr{L}^{-1}(g(s))[/math]?

yo, whats the min gpa requirement for cal poly school of engineering? srs q

>>8035583
to transfer btw

Can a regular language have uncountably many strings? My intuition says no but I'm not 100% sure.

>>8035143
Here's how induction works:

Show P(n) is true for 1, or whatever your base case is.

Then in the inductive step, you show that if there is some number for which P is true, it is also true for that number + 1. Since you already showed it's true for 1, it follows that it's true for 2. And because it's true for 2, it must be true for 3. And so on.

X2=2
I'm dumb, what is X?

>>8035597
1

>>8035597

[eqn]-e^{i\pi}+\frac{1}{12}+\sum_{n=1}^\infty n[/eqn]

>>8034502
These pops here sometimes, usually it's the hair's root fucking shit up, if you see one right in the center, I think you should pull it out.Works fine here.

>>8035578
yes, because the non-inverse Laplace transform is linear in precisely that sense.

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Is there any way to analytically solve this problem I'm having?

I'm trying to find the equation of an ellipse whose closest point to P is 5m away from it. P is known - (60, 25) - and the rectangle and ellipse are centered on the plane. Ignore the outer, grey ellipse.

I've just been trying to figure it out through trial and error and it's annoying. Can it be analytically solved?

>>8035690

Thanks

>>8035740

Are you in intro calc? From looking at it, I think you can solve it like an optimization problem and then, in a way, reverse-engineer the required ellipse

What is the best book to learn to prove?
I have no prior knowledge of uni math besides selftaught calculus and lin alg

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Where did all the ice water on comets come from?

I'm too dumb to get a degree in anything stem related, so I'm thinking a major in Finance with a minor in Accounting. Is this good?

>>8035832
stem encompasses a wide variety of majors,

and you dont even have to be "smart" to be a stem major

>>8035798
Book of Proof.

It's gratis.

>>8035586
Countably infinite number of strings.

>>8035590
I know, read my question again

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Why is [math]x_{i}^{T}x_{j} = x_{i} . x_{j}[/math]? My linear algebra is kinda shit, but the left hand side seems to result in a matrix, while the right hand side seems to result in a scalar. What am I missing

>>8035809
Jesus christ our lord and saviour.

>>8035770
Nah, no intro calc. High school mate. Aussie mathematics.

The main problem I'm having is how do I find the point on the ellipse that is closest to the corner P? I was thinking that maybe the point on the ellipse that is closest to P would be the point that intersects with the line going through the centre and P. Or perhaps optimisation is the best way to go?

>>8035950
If j were transposed instead of i then it would be a matrix.

>>8035994
Oh I see, thanks anon

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What's this formula about?

>>8036143
Transformers

>>8036150
Oh yeah it's fourier transform

I remember years ago when I was learning Physics at school, one of the formulas for the straight line motion with constant velocity was:
X = Xo + Vt.Now, I'm relearning physics using the book University Physics with Modern Physics and one the second chapter, the one about straight-line motion, there is only straight-line motion with constant acceleration and there's not a single instance of said formula in that whole chapter. Is there any reason why such formula/concept is not taught on the book? Is such formula irrelevant?

>>8035896
He answered your question exactly.

>>8032106
>Even though CS is a pretty modern field and some companies don't give a shot about your degree as long as you can do their work

That's not CS, that's software development/engineering. And that's true, most software companies care more about your github than your gpa. If you do solid on the interview and demonstrate knowledge, they won't even care about your degree.

I've read a statement in a quantuminfo book that is supposed to be a triviality, but i still can't see why it is true, maybe some mathfag can help:

Suppose you have the (bounded), hermitian linear operators over the finite dimensional Hilbert space [math]\mathcal{H}=\mathbb{C}^d[/math],equipped with the standard operator ordering [math]A\ge B\Leftrightarrow\langle\psi|A|\psi\rangle\ge\langle\psi|B|\psi\rangle\forall|\psi\rangle\in\mathcal{H}[/math] .Than you take the convex set [math]\mathcal{E}=\left{A\in\mathcal{B(H)}|A\ge 0, A\le\mathbb{1}\right}[/math].
The statement is that the extremal elements of [math]\mathcal{E}[/math], the ones that don't admit a convex decomposition ([math]A=\lambda B+(1-\lambda) C, 0\le\lambda\le 1 \Rightarrow \lambda\in\left{0,1\right}[/math]), are projectors.

I belive that i need to start out from the spectral theorem: All [math]A\in\mathcal{E}[/math] can be written as [math]A=\sum\limits_i\lambda_iP_i[/math] where [math]P_i[/math] are orthogonal projectors and [math]0\le\lambda_i\le 1[/math], the problem is that this is still not a proper convex composition, because the sum of [math]\lambda_i[/math] is not necessarily 1, and if i try to normalize A in a way that i get [math]\sum\limits_i\lambda_i=1[/math], than it is impossible that the normalized A is an extremal element.

>>8036297
\mathbb{1} doesn't work out of the box, which is annoying.

>>8036297
>>8036303
Fuck this board, it just doesn't seem to register half my math tags.

>>8032038
>>8032044

Haskell or LISP?

>>8036304
There's a preview button for a reason

Is Haskell really worth the awkward framing of every problem in terms of Category Theory?

This is what finally made me put it down.

I'd like to see something like Oz or Mercury become popular tho

>>8036343
There is? Are you sure it's not a browser extension you use?

Here's the fix for >>8036312. As a bonus I've fixed your typos too.

Suppose you have the (bounded), hermitian linear operators over the finite dimensional Hilbert space [math]\mathcal{H} = \mathbb{C}^d[/math], equipped with the standard operator ordering [math]A \ge B \Leftrightarrow \langle \psi |A| \psi \rangle \ge \langle \psi |B| \psi \rangle \forall | \psi \rangle \in \mathcal{H}[/math] . Then you take the convex set [math]\mathcal{E} = \left\lbrace A \in \mathcal{B(H)} |A \ge 0, A \le \mathbb{1} \right\rbrace[/math].
The statement is that the extremal elements of [math]\mathcal{E}[/math], the ones that don't admit a convex decomposition ([math]A= \lambda B+(1-\lambda ) C, 0 \le \lambda \le 1 \Rightarrow \lambda \in \left\lbrace 0,1 \right\rbrace[/math]), are projectors.

I belive that i need to start out from the spectral theorem: All [math]A\in\mathcal{E}[/math] can be written as [math]A= \sum \limits_i \lambda_i P_i[/math] where [math]P_i[/math] are orthogonal projectors and [math]0 \le \lambda_i \le 1[/math], the problem is that this is still not a proper convex composition, because the sum of [math]\lambda_i[/math] is not necessarily 1, and if i try to normalize A in a way that i get [math]\sum \limits_ i\lambda_i =1[/math], than it is impossible that the normalized A is an extremal element.

>>8036303
>>8036304
>the city of leltex

/sci/'s LelTeX has plenty of problems. For one, you need to put spaces in between some formulas. For example, if the formula involves {{ or }} you need to put spaces in between to make them { { or } } respectively eg. \sin{ \frac{x}{2} }. The TeX previewer won't catch stuff like this; it'll work in the previewer, but not on /sci/.

For another, if you want { or } to appear in the formula proper, you need to use \lbrace or \rbrace respectively in order for them to show.

>>8036365
>belive
Eh, I missed one. But ah well.

At least that's one of the few benefits of using mobile; you can view the entire formula and check where it went wrong, without having to change any settings. PC then allows you to proofread the formula, again without having to change settings.

>>8036365
Thank you friend, i still don't understand what i did wrong though.

>>8036377
In your particular case, there were two issues with your code. I'll put them in separate posts to avoid fucking up the formulas.

1st issue: Instead of using \left{ \right}, you should have used \left\lbrace \right\rbrace.

[math]\left{ \right}[/math]
[eqn]\left\lbrace \right\rbrace[/eqn]

See the difference?

>>8036377
>>8036397
Second issue: certain formulas need to be separated by a space, from the rest of the formula. \mathbb{1} is one of them. So
[eqn]\mathcal{H} =\mathbb{C}^d[/eqn]
[math]\mathcal{H}=\mathbb{C}^d[/math]

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>>8036397
>>8036403
>1st
>Second
Fug

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How do they keep the liquid fuel in cryogenic rockets cool? Are they just big enough that you don't need any active cooling systems as long as you fuel them right before launch?

>>8036409
yes. And they also chill the plumbing before launch and insulate the tanks.

And other rockets use storable fuels at room temperature (Proton, Long March, old Titans)

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How would I approach part d) of this question? Is there any reason to use the inverse of T in dii), for example?

>>8036606
(i) The nullity is the dimension of the kernel if i remember correctly, if that is Dim(V)-1 that means the dimension of the image of T, in other words the rank of T is 1.

(ii) No need for inverse. Whatever you put inside T gets mapped to the same one dimensional subspace, the answer follows from this.

(iii) You need to use that T(v) and T(w) are parallel and that T is linear.

>>8036702
Some quick additions:
(i) The nullity being Dim(V)-1 means that the things that don't get mapped to 0 are parallel with each other, and since T is linear, the dimension of the image also must be 1.

(ii) Since it's specified that w is part of the image and T(w)!=0, the image of T is not part if Ker(T), this means there is no problem with lambda being 0.

>>8036702
>>8036727
Thanks a lot

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>>8035809
come on can I get a legit answer for this.


like was it liquid water at some point or what

Why is
[math]
\sum_{k=1}^\infinity \frac{1}{k}
[/math]
not convergent?

How should I explain in an exam the main differences between PCA and FA?

Can someone explain rotating in FA in an understandable form? Is rotating related to EFA or CFA?

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>>8036884
Can be proved to be divergent using various convergence tests. Had to answer this question on it from when I was doing basic series in an earlier analysis course, maybe try the proof yourself?

what is the difference between [math]\cong[/math] and [math]\simeq[/math]? I'm in my first abstract algebra class right now and it seems like my professor uses them interchangeably.

like a question on an exam was, prove abelain group [math]G \simeq \mathbb{Z}_{p^{2}} [/math]. shouldn't it be [math]\cong[/math] since she wants us to show isomorphism?

In predicate logic, when saying something like:
[math]\exists x Px \wedge \exists Qx[/math]
Does the object x have to be the same object? I.e. does this say that some object exist in both P and Q, or is it simply saying that an object exists in P, and an object exists in Q, and they are not necessarily the same (but can be)?

>>8037752
Fucked up the latex, forgot the x on the second existential quantifier.
[math]\exists x Px \wedge \exists x Qx[/math]

>>8037393
Same shit.

>>8035809
Hydrogen and oxygen in relatively (300 K) hot molecular clouds formed water over long (hundreds of millions of years) and these lumped into bigger particles, together with other stuff during comet creation.

>>8036165
>I was learning Physics
learn form this
http://www.motionmountain.net/

>>8036297
get this book from libgen
Spectral Theory and Quantum Mechanics: With an Introduction to the Algebraic Formulation
Valter Moretti

it does not answer your question directly, but it is a nice book for aqft

>>8037752
no, the two x are not the same, because the ''and'' separate the quantifiers ''there is''

Someone please explain the difference between closed and compact supports. They both seem like the same thing to me.

>>8038080
I´ll take a look.
I managed to work out an answer today, still i wouldn´t dare to say it´s trivial when it took more than a page to prove. You can basically divide [math]\mathcal{ E }[/math] into convex subspaces of matrices that commute with eachother and construct linear bijections between the d-dimensional cube and each of these subspaces which map extremal points into extremal points.

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>>8038744
This is the page.

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>tfw accidentally posted this in another thread
How am I meant to solve for R?

/sci/ this is somewhat unrelated but how do I find out what period a particular transition metal belongs to?

How do I get a basic grasp of physics and chemistry (Up to 1st year college level) in a month and a half?
Math is easy as fuck, but physics and chemistry are a pain.

>>8039138
Feynman for physics

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How do I into categorical logic and Grothendieck toposes?

>>8032164

Some people put separate GPAs on, one for total and one for major specific. I think that's kind of lame unless there's a huge disparity. If you're still >3.6 I wouldn't worry about it for sure.

>>8033553
RWH is kinda shit desu.
>>8034413
This. I have a pdf of it if anyone wants, but chris is pretty reasonable if you email him.

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>>8032038

why doesn't this series converge

also is [math] 1-i>1[/math]

>>8035626
underrated

>>8039163
I can't tell you abt logic, but to into grothendieck topologies, best thing to do is to just start using them. Pick up a copy of Milne's étale cohomology. I hear a paperback version is coming out soon (like, any minute now), so maybe wait for that.

>>8039074
182.3 ohms

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>>8039074
For this particular circuit you could just eyeball it and say "Oh, there's 12 volts across the resistor R, and it needs to be 0.1 A. 12 = 0.1 * R", but you won't always know that. So here's how to solve using KVL.

First simplify the circuit as much as possible. But for this one it's already simplified, since you can't really combine the 200 ohm and 2 ohm resistors because of the other voltage source. Then, I usually just start doing KVL and KCL for all of the loops/nodes until I have enough shit to solve for the variable(s). I cbf to do latex right now, so have a shitty pic of my mongoloid handwriting. Also circuit simulators are your friend. http://www.falstad.com/circuit/

>>8039598
How did you get that? That makes no sense.

>>8032038
I'VE GOT A FEW STUPID QUESTIONS

>1)
What's the difference between a stupid question thread and a QTDDTOTT (questions that don't deserve their own thread thread)

>2)
Why is computer science a meme if AI is completely valid? Are you nerds really trying to imply math is a better route to AI than CS?

>3)
What can a non academic do to prove any math credentials? How far can one go in self studying pure math, and would anything produced (likely very small) ever be respected?

>>8039604
Also, will community college grades be required when I fill out an application to a job? When they ask for GPA, will it include community college, or only be uni?

>>8039604
>1)
They're pretty much the same.
>2)
I don't know how you go from "AI is completely valid" to "CS is not a meme".
CS is just a specialization inside of math, just like any science. Machine learning, the most popular application of "AI" these days, is essentially just statistics, but it is considered CS since you'd be retarded not to implement it with a computer. This is, indeed, a stupid question.
>3)
Assuming it's for the purpose of getting a job, just make something that requires the knowledge you want to demonstrate. Depending on the employer, that will show them that you actually know the shit and can actually apply it. If they want a degree period then you're obviously fucked.
>>8039612
Do you seriously expect a definite answer to that? Depends on the employer. If you're applying to fucking McDonald's, they probably don't give a shit. For a law firm, yeah I'd think so. If they don't specify, you can just ask them.

>>8039628
>CS is just a specialization inside of math, just like any science. Machine learning, the most popular application of "AI" these days, is essentially just statistics, but it is considered CS since you'd be retarded not to implement it with a computer. This is, indeed, a stupid question.

Bullshit, gl with implementing anything serious knowing only math/statistic behind it.

>>8039638
Yeah no shit, you need to know CS to do the CS part of it (implementing it on a computing device). You also need to know the actual math if you want to implement it to begin with. I think you missed the point.

>>8039138
These are actually pretty good, I think I'll drop my universityphysics book.

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Im finding linearly spaced arcs along a fuction using the standard forumla
definite_integral of sqrt ( 1 + (dy/dx)^2)

where y = A * sin ( (2 PI / lambda) * x)
however im getting an error around the part of
the function at quater wavelengths.

Im using simpsons rule to find the integrals.

Can anyone see what the problem might be?

>>8039787
by find the integrals i mean i search for the upper limit which gives a set value for linear spaces along the x - direction.

first stupid question:
how do you guys insert math equations ?

Secondly, how do I solve this trig identity problem:

cos(theta)+sin(theta)/cos(theta)-sin(theta) - cos(theta)-sin(theta)/cos(theta)+sin(theta)

>>8039855
oh shit, sorry. it equals 2tan(theta).

Rewritten:
cos(theta)+sin(theta)/cos(theta)-sin(theta) - cos(theta)-sin(theta)/cos(theta)+sin(theta) = 2tan(theta)

pls spoonfeed me daddy

>>8039860
>>8039855
Ok, it'd actually be PROPERLY rewritten as:
(cos(theta)+sin(theta))/(cos(theta)-sin(theta)) - (cos(theta)-sin(theta))/(cos(theta)+sin(theta)) = 2tan(theta)

>>8039604
All SQTs are QTDDTOTTs but not all QTDDTOTTs are SQTs.

>>8039878
*=2tan(2theta)

For the last time:
(cos(theta)+sin(theta))/(cos(theta)-sin(theta)) - (cos(theta)-sin(theta))/(cos(theta)+sin(theta)) = 2tan(2theta)

>>8039855
>how do you guys insert math equations ?
Read the fucking sticky.

>>8039886
i will if you answer my second question

>>8039894
It should be the other way round. You need to be able to present your answer in a readable manner.

>>8039911
Fuck
your question*

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Finished Calculus 2 this semester. What should I autodidact this summer while I'm studying abroad, /sci/?

>Linear Algebra

>Haskell

>Multivariable Calculus

>Differential Equations

I'd rather pick one and actually make progress instead of floundering around trying to learn a couple.

Currently undecided between a physics or applied math+statistics major, for reference.

>>8039915
>>8039911
[math]\frac{cos(\texttheta)+sin(\texttheta)}{cos(\texttheta)-sin(\texttheta)} - \frac{cos(\texttheta)-sin(\texttheta)}{cos(\texttheta)+sin(\texttheta)}

pls help now wise sensai

>>8039926
[math]\frac{cos(\texttheta)+sin(\texttheta)}{cos(\texttheta)-sin(\texttheta)} - \frac{cos(\texttheta)-sin(\texttheta)}{cos(\texttheta)+sin(\texttheta)}[/math]
>pls help now wise sensai
:3

>>8039927
FUCK. Theta didn't work, and it all equals 2tan(2theta), but come on I jumped through your hoops wise one, I need some halp

I know that
[math]2tan(\theta) = 2(\frac{2tan(\theta)}{1-tan^{2}(\theta)}[/math]

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>>8039926
>>8039927
>>8039932
Well it's a start. At least you tried.

[eqn]\frac{\cos{\theta}+\sin{\theta} }{\cos{\theta}-\sin{\theta} }-\frac{\cos{\theta}-\sin{\theta} }{\cos{\theta}+\sin{\theta} } \\
=\frac{(\cos{\theta}+\sin{\theta})(\cos{\theta}+\sin{\theta})}{(\cos{\theta}-\sin{\theta})(\cos{\theta}+\sin{\theta})}-\frac{(\cos{\theta}-\sin{\theta})(\cos{\theta}-\sin{\theta})}{(\cos{\theta}+\sin{\theta})(\cos{\theta}-\sin{\theta})} \\
=\frac{(\cos^2{\theta}+2\cos{\theta}\sin{\theta}+\sin^2{\theta})-(\cos^2{\theta}-2\cos{\theta}\sin{\theta}+\sin^2{\theta})}{(\cos{\theta}-\sin{\theta})(\cos{\theta}+\sin{\theta})} \\
=\frac{4\cos{\theta}\sin{\theta} }{\cos^2{\theta}-\sin^2{\theta} } \\
=\frac{2\sin{2\theta} }{\cos{2\theta} } = 2\tan{2\theta}[/eqn]

>>8039927
>>8039932
starting to piece it together. Getting a common denominator by squaring both sides.

>>8039936
i love you

but hey why didn't you just square both denominators to get a common D?

>>8032038
https://tryhaskell.org/

>>8039936
And yes, sorry to ask such a basic question without even knowing how to format. These past couple weeks have incredibly chaotic, zero time to catch up on studies and this problem is due tonight so thx anon I won't be such a pleb again I promise

>>8039943
Because squaring both denominators won't get you a common denominator?

>>8039952
duh, nvm. I was thinking the whole denominator on the left was negative, not just sin

>>8039954
>>8039952
what kind of gypsy magic happened just before you got
[math]\frac{4cos(\theta)sin(\theta)}{cos^{2}(\theta)-sin^{2}(\theta)}[/math]

>>8039952
Ignore the retard post. What is it called when you find a common denominator by doing what you did, multiplying each fraction by the other fractions denominator?

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>>8039956
holy fuck your LaTeX syntax is autistic...[eqn]\frac{4 \cos (\theta) \sin (\theta)}{\cos^{2} (\theta) - sin^{2} (\theta)}[/eqn]

>>8039963
>(\theta)
I doubt it.

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>>8039163
the typical books are

>>8039163
maria_pedicchio_&_walter_tholen_-_categorical_foundations_special_topics_in_order_topology_algebra_and_sheaf_theory_[cambridge_university_press_2004_9780521834148]

bart_jacobs_-_categorical_logic_and_type_theory_[elsevier_science_1999_9780444501707]

joachim_lambek_&_scott_-_introduction_to_higher_order_categorical_logic_[cambridge_university_press_1988_9780521356534]

I manage to install texlive 2016 and my documents compile fine!!!!!!

>>8039575
Stop guessing and shotgunning the problem. Think about what is and isn't happening to the summand in your series.
Plot powers of (1-i)^n for different values of n.
Saying anything more would answer the whole problem for you.

>>8039517
I want to pdf. Can you PLEASE share it? Been trying multiple sources for Haskell

Why does radioactive material decay at such a fixed, predictable rate?

>>8040202
Gotchu senpai. https://mega.nz/#!C18ihCqL!cVUvUrAicn7ylpQg6FhRDlxW0FE_nQ9qLiyONnQGULo

>>8040061
Thanks, family. I'll start with this.
>>8040064
And hopefully follow up with these.

How long can sperm remain viable on an environmental surface (outside the human body) after water exposure?

>>8040481
Depends on temperature and acidity.

>>8040487
What about lukewarm water? Cold? Hot? Freshwater? Saltwater? what temp and acidity can sperm survive in?

When should I round answers if I measure something? Does it count as contriving data if I use numbers calculated to, say more than 3sf when my measuring tool only goes to, say 3sf?

>>8040489
Yes.

I want to try and get the damping constant for a noise signal, it only needs to be a rough guess as I will use that parameter to properly fit it. Any ideas bros? I'm trying to find the number of discrete values until the amplitude drops to half but it's very noisy and returns a load of bollocks

>>8040551
I should expand on this, I'm not looking for help coding I just don't know of the mathematical tools. For example I have already used a Fourier Transform to get an estimation of the frequency

>>8039603
holy shit thank you so much. I knew I had to use KIrchoff's Rules but actually figuring out the loops is so confusing

>>8040399
Thank you!

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How do you know 6, 8 cant be there?

>>8040701
Because that's the only place that 2 can go in that 3x3, desu.

>>8040399
Fuck yeah dude I am >>8040620 this is awesome. I'm reading this shit as fast as I can

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how do i modulate with a carrier wave??

i have:
radio gun
coil transformer on power line

i want to add a wave to the power lines 60hz cycle

whats the process like?

What would have happend if STS 27 lost 1 mode tile?

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>>8040701
eZ brah

Can I let a variable equal the last term in an infinite series?

>>8040709
Thank you, now I see this

I won a scholarship to study on the other side of the world from my country, I'm going next year for 5 years to do my undergraduate degree. How do I deal with homesickness? Anyone else on the same situation? I just don't want my grandparents to die while I'm overseas (I love them both more than anything)

>>8040844
Try to keep in regular contact with your family, but also enjoy yourself, whether that's through an extensive friendship group, excessive flashlight usage or extreme vigour for learning; if your family sees you happy, they won't worry about you (as much) and they'll be happy

Not really much you can do except try and make sure they're happy, it'll be a lot better if they die knowing you were enjoying and improving yourself

Phew, that was heavy, breh. What are you studying?

>>8040844
Give destination and origin (countries), its important. In general try to stick to other foreigners. Especially if destination's lang is not your mother tongue.

>>8040857
ME, yeah, I appreciate your advice anon. Made me feel better.
>>8040876
Japan, Paraguay.

What is the actual difference between science and religion? They seem like the same thing to me.

>>8041188

Science uses logic and experiments to prove their theories. Religion yells "You're the devil" if you don't believe in God and that "you must have faith" to the ones who question if there is a God.

>>8041228
But doesn't science also ask that you have faith? Yeah, they try to shower you with evidence or proof, but at the very core of all of their proofs there is always some initial starting premise that you are expected to take on faith alone. How is this any different from religion then?

How come Medi-Cal wants the income of both my parents when I am the only one who is applying for IEHP? I'm over 25 and live in California.

>>8032038
if you mean in your editor, it's
:syntax on
in Vim and
M-x haskell-mode
in Emacs

But you're probably talking about the REPL.
Well, sorry, that kind of behaviour doesn't ship with a repl. If you use emacs it MIGHT do it if you start the repl inside emacs itself through M-x run-haskell but otherwise you'd need an external program that either acts on top of your repl or somehow enhances your repl. I don't know i haskell has such a thing though, most languages don't

>>8041228
Yeah, nice undergraduate studies here.
Scientists demand to be paid in exchange of creating formal systems that they claim model something, and since they cannot show the something, they claim that the something is reality.

Planning to transfer into an engineering program. I can easily finish a couple courses and get a compsci associate before doing so. Should I bother?

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>>8036362

>>8041239
Give an example

>>8042048
>we can't know nuffink

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I'm making a custom bluetooth speaker from a 4inch coaxial car speaker, a TDA7492P 50W+50W Amplifier and a 12V Lithium-Ion battery.

My problem is that I'm getting too much distortion long before I reach the maximum volume level permitted, even at the lowest gain setting.

Is there a way to reduce this distortion? I can't use a ground loop isolator since the bluetooth chip is the only interface and it's soldered to the board.

>>8042562
Well for example, a lot of the mechanics we "know" about how the universe works require that we take on faith alone that certain concepts such as gravity exist. Can we prove that gravity exists? We can demonstrate that gravity could potentially explain certain physical phenomena, but that is not the same thing as proving that it is actually the thing responsible for those phenomena. It's like a creationist saying "look, the Bible provides a perfectly valid explanation for how things coming to be" and then expecting you to accept that this must be the valid explanation simply because it fits the facts as we currently know them.

>>8042748
What the fuck are you even saying

There is evidence that objects with mass attract other objects with mass, and the attractions follow the inverse square law. It's empirical and very easily reproducibie

>>8042756
No, "objects with mass attracting other objects with mass" is just a convenient explanation for people to explain physical phenomena. There is no way of proving that it is indeed the correct explanation. For example what if rather than "attraction" it is simply that the objects are expanding at a constant rate, and will eventually move out to "catch" other nearby objects? We think that we are "attracted" to the surface of the Earth but in fact it is just that we are incapable of perceiving that we are just being swept along with its constantly expanding surface, because we are expanding at the same rate.

Can you really prove that your explanation is correct and mine is wrong? Or is it simply your faith in the concept of gravity that leads you to believe that it must be true?

>>8042761
It's not an explanation it's a description you pleb

>>8042764
But you still can't prove it beyond the subjective level, anymore than you can prove that the sky is blue or the grass is green. Those kinds of descriptions are relevant only to our own sensory system and don't give any information about how the universe actually works.

>>8042769
>using the word prove outside of maths

The description is not only relevant to us, all of the observable universe follows the law of gravity and there's no reason to believe the universe is different, and it can be used to make predictions . And the theory of gravity does give us more info about how the universe works

What are you studying, you don't sound like you're in STEM at all desu

>>8034502
ingrown hairs, nothing more.

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>>8042756
>There is evidence that objects with mass attract other objects with mass, and the attractions follow the inverse square law. It's empirical and very easily reproducible
This is all very fuzzy from a fundamental standpoint.
Of course, nobody will really argue that the theory with the inverse square law is extremely useful, and "right" in the sense that we can use electrodynamics and gravity to build stuff.
But even uttering the phrase "objects with mass" relies on a preliminary physical theory - and the convention to act as if we knew "mass" is physical reality. Or "object", for that matter.

(For example you might take quantum mechanics seriously, where the time development of the wave function that determines probabilities of observable is given by some mathematical operator. The notion of "force" is not part of this framework and we can at best identify the some expectation value of some constructing in the operator algebra of the theory F=<F'> with "force" identify some numbers as "mass" of particles and say that the time dependent expectation value of the position <x> is behaving accordings to
m·d^2<x>/dt^2 = <F'>
But this is all just an exercise - there is no force in quantum mechanics unless you identify it there, somewhere. Masses become fuzzy if you consider Lagrangians of fundamental theories, that are renormalized (and a billion terms are potentially added) when you compute anything, and space and times are probably not to be saved either.)

My point is that if you start talking about physics, you do it in terms of some theory and all you say about the reality of things is severely circular - tbqh it feels saver to take a Mach'ian approach and view the world as an empiricist
- because realizing talking in a non-mathematical language is producing statements that have no sensible truth value ... this realization doesn't make electrodynamics any less applicable.

>>8042777
>it's a what does it even mean we can't know nuffin post
No thanks

>>8042780
The issues with the realist ideology shouldn't rustle you, imho. Sure, if you decline it with a "no, thanks", you can take a leap of faith if you don't like that insight :^)

>>8039917
You could do some Linear Algebra programming exercises, 'Coding the Matrix' will teach you some fun and practical stuff

>>8042756
mass is poorly defined in GR, so be careful with mass.

>>8042834
Mass is the property an object has if it causes spacetime distortions :^)

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how can i calculate the force applied on an object after the collision so that i can find the torque?

Should I major in chemistry or math, or double major? Which is one better kept as a hobby, not a profession? Probably chem, huh

Also, what's the consensus on double majoring? Am I dulluting myself, or am I doubling my potential job market for the same price?

>>8043921
*diluting

Anyway, if chemistry is kept as a hobby, how can I get lab skills, other than by reading? Can I just volunteer or something?

I need to be skilled chemist.

>>8043778
>force applied
>after collision
does not compute

>>8043921
You don't have to be a chemist or a mathematician if you major in either of those.

>>8043983
What's your point?

>>8044007
>>8043983
I already do low level chemistry (only synthesis really) out of hobby, and have more recently been taking up math. Other majors of interest are CS (into coding and security) and engineering, but idfk. Have to decide this fall though

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Hey mates, in which case a quadratic function graph doesn't intercept the x-axis? Thanks!

>>8044020
format this better, illegible
and ask your question better

>>8044020
B^2 -4ac must be >0. If not, you'll have imaginary intercepts not on the x-axis

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Help me with the red dot integrals, please.

can someone explain to me how
[math]\frac{sec x}{csc x} = sec x(\frac{1}{csc}[/math]

>>8044176
pls i don't get it

>>8044195
I also don't get, similarly, how
[math]\frac{sec x}{2sin x} = \frac{1}{2sin x}[/math]

>>8044203
>>8044195
>>8044176
it has to be something really obvious and dumb, pls help

>>8044176
sec/csc = sec * 1/csc for the same reason 3/5 = 3 * 1/5

>>8044203
this is just not true for obvious reasons, plug it into wolfram alpha

troll?

>>8044316
Is it really not true? No, not troll, just firmly retarded and frustrated, it was a homework problem.

>>8044316
so sec * 1/csc was basically factored from sec/csc?

I'm in trig and took some time off, having trouble with basic shit like rules for fractions.

>>8044332

You shouldn't be in trig if you're having trouble with basic algebra. Use Khan Academy or PatrickJMT on youtube to learn.

http://www.feynmanlectures.caltech.edu/I_16.html#Ch16-S4

In figure 16-3, why did the horizontal velocity u for particle 2 not undergo the Lorentz transformation?

>>8043921
Are you me, I can't decide even though I've been watching quite a few lectures, that's why I'm going with a NatSci course

I'd say chem is the one better kept as a hobby, but if you have the autism and intelligence double major

>>8040718
give this one an answer

I'm reading and intro to particle physics and I don't understand when instead of the usual notation for decays and reactions, e.g. p + p ---> K + D sometimes there are reactions written with couples of particles coupled together, like np ---> yd

What does it mean?

>>8044052
Thanks!!

>>8044797
What's a NatSci course?

If chem is better kept as a hobby, how do I git gud at chemistry without majoring in it? Seems hard without spending lots of time a lab

>>8045340
Not him but take chem as a minor, maybe?

>>8045340
Natural Sciences, I don't know if unis in burgerland have it. It's basically a pick and choose from any of the Sciences + maths and specialise or go broad
We don't have majors/minors

It is pretty hard, I'd say minor like the other guy said
If you want to do mostly theoretical though you don't need labs