/sqt/ Stupid Questions Thread

Whats the physical measure of mass floating within a star system beyond the star itself called? Do astronomers index that or is it too early to estimate?

What are some good stars in our neighborhood to turn into matryoshka brains?

What are some good books to learn electronics?

There aren't any. To learn electronics you have to do electronics projects.

Veeky Forums-science.wikia.com/wiki/Electrical_and_Electronics_Engineering#Circuit_Analysis
Veeky Forums-science.wikia.com/wiki/Electrical_and_Electronics_Engineering#Electronics
Veeky Forums-science.wikia.com/wiki/Electrical_and_Electronics_Engineering#Bible
Veeky Forums-science.wikia.com/wiki/Electrical_and_Electronics_Engineering#Analog_Electronics

Veeky Forums-science.wikia.com/wiki/Biology_Textbook_Recommendations#Physiology

Thanks!

How did u get that answer

Interested in Tesla. Don't understand fuck all I'm reading. 3 6 9 explains the universe? Wut? Where do I start? And I mean Start.
Is there even any chance for a brainlet to grasp this shit?

Explain MCMC to me like I'm retarded

What's MCMC?

markov chain monte carlo

Construct a Markov chain whose stationary distribution is the posterior of your model given data and iterate it until the desired number of samples are obtained.

Math retard here. Can I get an explanation why Zd = Za + Zb means d is gcd(a,b). I can follow thr proofs and see that they aren't wrong but i cannot get that intuitive understanding. Btw Z is the integers

cmon guys

Hint: [math]d\,\in\,a\,\mathbf Z\,+\,b\,\mathbf Z[/math]

This a total brainlet question, butI'm teaching myself some basic programming in Python and I'm stuck on printing this table correctly.

Here's my the current output:
n Triangular Numbers
--- --------------
5 15.0
5 15.0
5 15.0
5 15.0
5 15.0
Here's what I'm trying to do:

n Triangular Numbers
--- --------------
1 1
2 3
3 6
4 10
5 15

Can anyone help me out here?
Pic related

i is the variable that changes during each iteration of the loop, not n

you never use i in the loop, change
n *(n + 1) / 2 too i*(i +1) / 2

Let [math] x,y,n [/math] be integers. Is it true that [math] n^4 + \frac{4n^3 x}{y} + \frac{6n^2 x^2}{y^2} + \frac{4nx^3}{y^3} [/math] is an integer if and only if [math] \frac{4nx^3}{y^3} [/math] is an integer?

I have to find a vector which is not an element in the Span{V1,V2} where V1 and V2 are:
[math]\begin{bmatrix}1\\1\end{bmatrix}\begin{bmatrix}2\\-1\end{bmatrix}[/math]

So I tried just solving this system where the last column is the right hand side of the equations:
[math]\begin{bmatrix}1&2&a\\1&-1&b\end{bmatrix}[/math]
Which gives me:
[math]\begin{bmatrix}1&0&a-\frac{2(a-b)}{3}\\0&1&\frac{b-a}{3}\end{bmatrix}[/math]

Since there's no row with [0...0 | b], I assume no such vector can be found?

But clearly I'm an idiot and must have done everything wrong somehow.

Why is it that sometimes after I fuck a girl my cock still smells like her pussy up to a week after fucking her? I take showers and shit. Clean STD panel.

This is more of a career question. I did my undergrad in engineering and am currently serving in the military. In the military I've become fairly interested in pure maths and have gone through a few books on analysis (I had some brief exposure to complex analysis as an undergrad but that's it). If I wanted to pursue maths further after the military, I think I'd be locked out of any graduate prorgam since my undergraduate coursework wouldn't be sufficient background. Would it be worth it to get a second BSc level degree in maths or should I just fuck off and keep it as a hobby?

Those two vectors form a basis of R^2 so you won’t find any vector of the form [a,b], a,b in R that is not in the span.
Though I suppose you could say [a,b,c] is technically an answer

Why the buoyancy force on free body diagrams aren't in center of mass of the object?

any vector with more components than the rank of the matrix will do

>Why is it that sometimes after I fuck a girl my cock still smells like her pussy up to a week after fucking her? I take showers and shit.
Do you use soap?

Yes

Congratulations, you are now the proud owner of an STD!

Uhh... did you read the last part? I had a panel run and nothing came up.

It can take up to 6 months for some STI's to show up on tests

So my shitty, human excuse for an olfactory system can detect things that a medical test can't?

Thanks!

If your dick smells like the a plague-infected rat despite using soap, I suppose some test is gonna detect something.

>a plague-infected rat
Does pussy really smell that bad?

For 25, write out what the factorials actually mean and cancel things out of the fraction, then notice a regularity in the remaining numbers.

What is a good book on sequences and series? One that'll teach me convergence tests and theorems in general with detailed proofs (basically looking for a rigorous book on the subject)

Please, I really want to study that

It can. The only reason for suspecting STD here though is the persistence of the smell regardless of how pleasant/unpleasant it is found.

It's either that or the person in question is simply confusing smells.

from Zd ⊆ Za+Zb
Let X = (Za+Zb)∖Zd
Let x be an arbitrary element of X

Since x∈ X ⊆ Za+Zb, x=n*a+m*b for some n,m∈Z
Therefore d|x so x = k*d for some k∈Z
Hence x∈Zd.
But this contradicts the construction of X
So there can be no such x
Since x was arbitrary, X must be empty
Therefore (Za+Zb)⊆Zd
And (Za+Zb) = Zd
QED

>butI'm teaching myself some basic programming in Python

Learn C++14

>trisum = n*(n+1)/2
>15.0

You're using python 3 which made python even more autistic. In python 2, that would have been integer/integer = integer like every other language under the sun. But python 3 though that was "too confusing for the normies" so they made it integer/integer = floating point. Now you're stuck with floats even if you don't write "i*(i+1)/2.0".

Write "print(i, '\t', int(trisum))" to lob off the decimal point.

Also range(a,b) is from [a,b) so you want range(n+1)

>Let x be an arbitrary element
>Since x was arbitrary
This is engineer level garbage writing.

>This is engineer level garbage writing.
What's wrong with it?

>But python 3 though that was "too confusing for the normies" so they made it integer/integer = floating point.
jesus

Guido is proof that the brainlet continuum is only satisfied in a nonstandard model.

u can just wiki that user

newton's method is for women, real men use the secant method

whats the difference between electricity and magnetism? Why are magnet poles labeled north and south if they are just positive and negative charges that attract/repel kind of like a voltage causes electrical current flow? I am aware this is definitely a stupid question....

>whats the difference between electricity and magnetism?
about 90 degrees

(n+nx/y)^4

Nobody (except engineers) writes like that. When you say "let [math]x \in X[/math]" in a proof, it's clear that you are proving something of the form [math]\forall x \in X : P(x)[/math], so x is arbitrary.

Magnetism is just a relativistic illusion of electricity.

>I'm using logical quantifiers!
>It's now 1000 times more rigorous!

Brainlet cs majors belong in

>whats the difference between electricity and magnetism?
Only one of them exists physically.

You appear to be a brainlet C"S" major yourself if you think anyone actually writes quantifiers in papers outside of logic. You are proving a universally quantified statement though, so writing the garbage you did is redundant.
>rigorous
I said nothing about "rigor". It's simply a bad writing style.

So basically, what he typed wasn't wrong, you just don't like it.

I didn't claim anything was wrong. You will simply be laughed at for writing that in anything serious, just giving you a heads up.

Is there a definition of eigenvectors in a group theory or topology sense?

In the sense that the direction or span of the vector remains unchanged during a transformation, I'd like to think you can discuss properties of symmetry belonging to this eigenvector from a point of view of group theory and maybe topology.

Can you please help me on this? I'm getting stuck

Why is it that, given that the maximum of a subset of R exists, it is ALWAYS equal to the least upper bound of that same subset?

And, for example, considering the set of all real numbers such that x > 4, is 4 the least upper bound? How can I prove that?

Also I'd really appreciate any source of info (books, videos, anything really) regarding the bounding of R subsets. My calculus course will be very heavy on this and most books I've looked for tend to skip this subject.

>Why is it that, given that the maximum of a subset of R exists, it is ALWAYS equal to the least upper bound of that same subset?
Look at the definition of least upper bound and then try to prove that the maximum fits this definition.

>And, for example, considering the set of all real numbers such that x > 4, is 4 the least upper bound?
No, but if you meant x

en.wikipedia.org/wiki/Group_action#Orbits_and_stabilizers

thanks i'll give it a read.

>Write "print(i, '\t', int(trisum))" to lob off the decimal point.

After my original post I totally realized that I neglected to write it as an int. I wasn't too concerned whether or not it was a float or an int, I was more focused on the logic. But definitely noted.

>Also range(a,b) is from [a,b) so you want range(n+1)

Just noticed and corrected that before I read this post. Thanks for pointing that out though! I've written some babby tier scripts in R and got used to the whole "not starting with 0" thing.

>Learn C++14
This is definitely a total brainlet question, but I'm not familiar with lower level languages, mainly the whole deal with compilers. Is a compiler available for free or is it something which I would need to pay for?

Sorry for the n00b question, I've only used Python and a little bit of R so anything C related is a mystery to me at the moment. I'm an economics/statistics undergrad so R and Python are the main languages used at my uni.

>After my original post I totally realized that I neglected to write it as an int.

Shit I meant float.

Let S⊆R and assume max(S) exits. By definition:
max(S) = x∈S s.t. (∀s∈S) s≤x
sup(S) = z∈R s.t. (∀s∈S) s≤z & (∀r∈R) if (∀s∈S) s≤r, then z≤r

If x

>This is definitely a total brainlet question, but I'm not familiar with lower level languages, mainly the whole deal with compilers. Is a compiler available for free or is it something which I would need to pay for?

visualstudio.com/downloads/
clang.llvm.org/

>visualstudio.com/downloads/
Well fuck me. Thanks for the links!

I've studied a lot of proofs, that's not really the problem. I couldn't get good maximum and supreme definitions to work with though. That's a really good book your recced me, it helped me a lot.

helped me a lot in the past, that's what I tried to mean lol,

the last version of this was too trivial

you were very kind to answer without being patronising

how many gets should a thread with n replies have for it to have a significantly low number of gets

You can get this dick n your ass

(Alpha must be an integer btw)

So the integral is equal to 1,234,567! - 999,999!

I have to find a number to subtract from (1,234,567! - 999,999!) to make it a perfect square.

Anyone have any ideas?

Yes, I know...
the integral is equal to 1,234,567! - 999,999!

But those are really big numbers.

The problem I am having is finding an integer to subtract from the integral to make it a perfect square.

Never mind, I may have figured it out

s=round(sqrt(1234567!-999999!))
-alpha = s^2-1234567!+999999!

I studied Biomedical Engineering with a focus in computational modeling and we ALWAYS used Matlab in both undergrad and grad at 2 different schools. Yet none of the job postings I look at want Matlab. Should I learn another language? R and Python seem to be requested frequently

can anyone shed some light on this

There's no such thing as 'real contact', if by contact we mean our human perception of touch. Energies perturbing fields is all there are.

"When you press on something... it's not the atoms touching each other". Even if atoms were 'touching each other', considering that subatomic particles are composed of quarks, it would still be just energies perturbing each other.

I'm self-studying Basic Mathematics by Serge Lang. His exercises are straightforward for the most part, but any questions involving proofs are completely lost on me and I end up referring to the back of the book.

Are there any good guides to constructing algebraic proofs on a basic level?

Lang is a meme.

so what you're really saying also is that the concept of things physically existing is misled? everything is just energy?

Ah really? How so? Are there any better I should start out with?

zeno's paradox at the atomic level

I gave in and installed Matlab to do some problems for my modern physics course, anything I should know off the bat? I'm just using it right now for some integrals that are a pain in the ass

Python. If you know Matlab it will be a pretty quick learn.

Employed BME w/ more than a Bachelors

Skim a book to get an idea of what functions are available and how to do stuff:
Veeky Forums-science.wikia.com/wiki/Programming_Textbook_Recommendations#Matlab

Always google first to see if there's a built in method that can do what you want or a subpart of it

Vectorize your code whenever possible. E.g. don't write:
>for i=1:length(A)
>>if(A(i)>>A(i)=0;
>>end %if
>end %for
But write
>A(A

Read Book of Proof (people.vcu.edu/~rhammack/BookOfProof/)

Give an example question of what you're struggling on.

Proofs are hard and not really that important if you simply want to understand and solve problems, some people here actually have classes on nothing but proving Theorems. But if you are motivated to prove them, the right way to go is to cover the whole subject and then try to attack the proofs once you get the WHOLE idea.

This is """fine""" only for engineers and their ilk, and the book isn't titled "Basic Engineering".

>engineers
>engineers
>engineers

Did your engineer roommate rape your ass in your sleep or something?

So I had pic related, the question was what is the value of integral from 1/2 to 3 of f(x)dx.
I tried to change bounds but it lead no where, so I simply replace the bounds of 1/2 and 3 bc I ran out of ideas, to get this answer : 1/2-(1/2)/3^2.
whats the real answer here, thanks.

integral from 1/2 to 3 =
integral from 1/2 to 1 + integral from 1 to 3 =
-(integral from 1 to 1/2) + integral from 1 to 3

ah I see it, Im an idiot but then why state 1-1/b^2 though?
The answer could have very well been given without that info. It seems to hold true even if the -a- bound is lower than 1.
Or is it bc I have to replace the bounds in here 1-1/b^2 for the two integrals in your answer?

This is a serious question. How do I stop getting angry at people I perceive as brainlets? I don't really care about being right and wrong, I just want to not get angry at them.