STUPID QUESTIONS THREAD

I don't have general physics courses, but for some reason the okder profs meme this into existence.

In Taylor's Inequality, what is the M supposed to represent? How do you arrive at M?

It just means the derivative is bounded.

Am I supposed to find the smallest M can be on the interval?

That looks like a Calculus book from Stewart. Am I right?

Comes complete with a very poor online reader.

just read the inequality, it says nothing about smallest, any upper bound M will do

What's a good way to deal with odd terms in the derivation for a dispersion relation?

The standard approach to doing EM dispersion relations is to linearize all the equations and (hopefully) put everything in terms of some first-order wave potential that then cancels out of Poisson's equation at the end... but what if you have a first-order term that isn't dependent on the wave potential? Is there still a way to get a linear wave solution out of this or do you need to do a full, non-linear dispersion?

Can someone give a good description on what a quantum dicking would be? Is screwing around in the 4th diminution count as a quantum dicking or something?

Given a right triangle with a certain perimeter, p, (and the side lengths are all integers), can we assume that the perimeter will be a multiple of one of the sides?

All I'm given is that a triangle has p = 120, and the three answers (with only integers in them) are as follows:
{20,48,52}, {24,45,51}, {30,40,50}
I noticed that the smallest number always divides evenly into p, and was wondering if this was pure coincidence or not.

no

consider the (88, 105, 137) triangle which has perimeter 330

epin

With that said, I think there is something to be said about the factors of the perimeter being involved in the answer, because 88 is a multiple of a factor of 330 (the gcd of 88 and 330 is 22, and 88/22 == 4)

So I think a *possible* angle of attack would be to get the factors of a number, and test possible sides that are multiples of the factors (but less than the perimeter and/or fulfill a+ b > c)

Thoughts?

If x = (x_0, x_1, x_2, ...) and y = (y_0, y_1, y_2, ...) are in [math]\ell^2[/math], does it follow their "Cauchy product" is in [math]\ell^2[/math]. By this I mean the following: define z = (z_0, z_1, z_2, ...), where [math]z_n = \sum_{k=0}^n x_ky_{n-k}[/math]. Is z an element of [math]\ell^2[/math]?

find p

P^(-3/2)=1/27 therfore p^3/2 = 27 now cube root of both sides so p^1/2 = 3 so p =9

log_a(b) = x if and only if a^x = b. So then your problem is equivalent to solving p^(-3/2) = 1/27, so p = (1/27)^(-2/3) = (27)^(2/3) = 3^2 = 9.

thanks lads

God fucking damn it.... I just remembered Pythagorean triples are a thing

>Carefully add 100 mL of concentrated sulfuric acid to 5 mL of 40 percent
formaldehyde (v:v, formaldehyde:water)
>v:v, formaldehyde:water

does this mean 40% formaldehyde to 60% water or a 1:1 ratio of water and 40% formaldehyde?

what does the v:v mean?

G is a group, a and b are elements of G with finite order s.t: ab=ba. For all integers m, a^m is not a power of b, and for all non-zero integers k, b^k is not a power of a. Observe that this ensures that a^nb^n=e implies means that both a and b are e (e is the identity). Show that the order of ab is the lcm of the order of a and b.

What I did:
Noticing ab=ba, I used induction to prove that (ab)^k = a^kb^k. We want the identity of (ab), so setting (ab)^k=e, which would (from what the problem stated) imply that both a and b are the identity. This would complete it all (a = e, b = e, both have order 1, lcm(1,1) is just 1, blabla). This sounds wrong, kinda. Where did I fuck up?

>imply that both a and b are the identity

You mean [math]a^k[/math] and [math]b^k[/math]. You want to show [math]k=\lcm(|a|,|b|)[/math]. To complete your argument, what can we say about [math]k[/math] if [math]a^k=e[/math] and [math]b^k=e[/math]?

But the problem states this. So if I have (ab)^k=e, we must have a^kb^k = e, which would imply a=b=e, no? Also, |a| denotes the order of a, right? Like, I understand that if a^k=e, and b^k=e then k must be a common multiple of both a and b (then lcm = order follows etc), but my first point is really making me consider suicide.

but didn't you say for all integers k a^k is not a power of b? we have a problem here. Post the whole image if you got it digitally already

...

it should say a^nb^n=e implies a^n=e and b^n=e

reeeeeeeeeeeeeee
fucking TA

aite, then it's pretty simple, ty homie.

Well your book is straight-up lying to you. Let [math]G=\mathbb{Z}_6 \times \mathbb{Z}_8[/math], [math]a=(1,0)[/math], and [math]b=(0,1)[/math].

Obviously neither [math]a[/math] nor [math]b[/math] are the identity, but [math]24(a+b)=(0,0)[/math].

I'm guessing that's just a typo. And yes, [math]|a|[/math] means the order of [math]a[/math].

Yeah, got it, thanks dude.

Are there... courses on atomic physics an undergrad can take?
And would it make sense to learn atomic physics before taking chemistry?
I want to know if it would make chemistry easier if you knew very well what was going on in the atoms and molecules from the physical standpoint.

Right now my main issue with chemistry is it's so much memorization and none of it makes intuitive sense. My physics courses are super easy because you can visualize what's happening very well, draw some flow charts, maybe a free body diagram, etc. I want to be able approach chemistry like this. Could I do it if I knew atomic physics?

Silly question: Are "transcendentals" shit like e or what?

Does "Early transcendentals" mean they cover logs, ln, e, etc in the derivative portions instead of saving them until halfway through the integral chapters?

transcendental numbers are numbers that aren't roots of integer polynomials, e and pi are examples

but early and late transcendentals is explained here
math.stackexchange.com/questions/535283/whats-the-difference-between-early-transcendentals-and-late-transcendentals

That was great. Thanks.

(Regarding atomic physics)

Well, all other things being equal, it couldn't hurt. But I think that the time investment might be quite large.

I'm a physicist, but my understanding is that chemistry courses (on atoms) focus heavily on bonding, electron shells and energy levels, at least until you take specific courses on physical chemistry or even just straight physics.

Physics courses tend to take a slightly different approach. They deal with the exact physics of easily understood atoms. You learn about hydrogen, then helium, then alkali metals. Usually, the student has taken quantum mechanics and relativity; atomic physics is a nice way to show some applications and demonstrate it all in action.

But concepts like bonding, reactions etc. are not really covered. It's a lot of quantum mechanics, and I don't know how much detail you do on that at undergrad level. What's more, physics courses like to stick with simple elements (because they can be solved relatively easily) and then just hand-wave the rest of the periodic table with 'we need computers'. Indeed, it's always 'atoms', never 'molecules'.

Nonetheless, if you are reasonably motivated and want some physical understanding, at least of the hydrogen and helium atoms, then I can recommend a couple of books.

Atomic Physics by C.J. Foot - This is a classic book on atomic physics. It's very clear and follows a sensible route. It probably assumes a little bit of QM.

The Physics of Atoms and Quanta by Haken - This has introductory chapters on quantum physics and might be more suitable if you haven't seen much.

Lets say I have a function f(x0,y0) = k and another function f(x1,y1) = k .
Implying I know k how do I get x0,y0 and x1,y1 ?

Thanks for the recommendations. I'll give them a look.

You can't

One of the most interesting questions I always wanted to solve was this: what is the analytic form of the eigenstates of the fermionic spin Hamiltonian?

I was also interested in how stochasticism can arise from determinism. Nature has these deterministic laws that somehow yield stochastic processes, and Nature is also telling us that, due to the expectation that correct mathematical formulae are beautiful, we should have analytical functions to use in representation of spin that doesn't ``cheat'' by using spinors.

1st Year EE major, the only class that I have above 90s on all assignments is in Calc II. Am I a brainlet?

AutoCorrelation

What is this?

Glucose

Best biology book?

A glucose disaccharide

Fuck you

If I am trying to determine proliferation of cells over time with the addition of drugs, can I work out the cell density by creating a standard curve? For example reading plates via MTT assay in 24, 48 and 72 hour periods with 50k Cells/mL, then use these values to determine cell density increase after the specified time periods

A Standard curve made from from 10x6 - 0 cells/mL/Abs 570nm

Microwaveable burritos that you microwave in the wrapper: will the BPA kill me?

Not at all...EE's pretty hard. Keep trying!

T-thanks.

>Get the factor in the root
WTF? If p > 0 it's completely fucking wrong.

campbell or brooker

maltose maybe

math is not my field

but 2p = sqrt(4p^2)

sqrt(4p^2)*sqrt(-p)=sqrt(4p^2*-p)=sqrt(-4p^3)

>but 2p = sqrt(4p^2)
only if p>=0

if p

n = k = 0

I don't see a problem?

Well that maybe means you have good mathematical foundation but require more learning and understanding of electric theory

Well as you can CLEARLY FUCKING SEE there's no answer with +/-, just one or the other.

like I said, math is not my field, so take what I write with a pinch of salt

I'm just thinking if that is an e-test, and they gave you no conditions (as in you can't add "p>=0"), then why bother

again, don't trust me, so look at pic related

how do i make selenious acid?

how did post eukaryotic cells acquire energy before engulfing mitochondrial and chloroplastic prokaryotes in the endosymbiont theory?

whoops i mean 'pre-eukaryotes' not post lol

what

Is there a reason planets in our solar system rotate around the sun in the same direction?

Since the other thread looks dead, I'll quote my question:

Ops, didn't mean to quote you.

> If p > 0
guess what

If e=mc^2, does that mean it could be possible to turn a person into a bomb? I mean, people have mass right so they have energy.

Why are there still wind tunnels for cars? Why hasn't a computer been able to simulate a wind tunnel for cars? Is fluid mechanics that difficult to model?

When you're not at a university, fuck all math

Is teleporting and time travel the same thing? If you could do one, couldnt you also, in consequence do the other as well? Is this question stupid?

Not really sorry Muhammad

What the fuck is that quotient group? R mod ? What's ?

< x> means subgroup generated by x

so is all the multiples of 2pi

so R/ are equivalence classes mod 2pi, i.e. you can take for representatives the numbers in [0,2pi)

Neither are possible so how the fuck would anyone on Veeky Forums know?

based, ty

is this a valid proof that [math] 2^{n} > n [/math]?

[math] P(1) : 2^{1} > 1 \\
P(n+1) : \\
2^{n+1} = 2^{1} \cdot 2^{n} > 2 \cdot n \\
n < \frac{2^{1} \dot 2^{n}}{2^{1}} \\
n < 2^{n+1} \cdot 2^{-1} \\
n < 2^{n} \\
Therefore, if P(n) \rightarrow P(n+1) [/math]

I think I'm being circular here, should've shown explicitly that 2^(n+1) > n+1

I'm pretty dumb. I'm currently going for Civil Engineering , but recently have been thinking about switching to computer science because I'm more interested in it.

Which is easier? It's important for me to decide now because I'm about to transfer schools, so I need to be serious about what i'm doing. I'm thinking computer science would be harder because on top of math, i'd also have to learn programming. Am I right?

So I've proved this up until the last point, about the n distinct points in {|z|

>> i can learn topology with poor base in trigonometry?
I already start read topology by munkres

Can someone explain to me why this is being marked as wrong? AFAIK this should be the correct answer, what am I missing?

Depends on the school. At my alma mater they were similar in terms of difficulty for much of the engineering department (and by that I mean it was difficult and relatively rigourous in maths). Some comp sci programs are very rigorous and focus on the actual computer science, i.e. the science of computing, i.e. what amounts to lots of applied math. Then there are some programs that do the quick and dirty emphasis on less theory, more practical; i.e. computer programming rather than computer science (I can elaborate on this significant difference if you'd like). I think the later is relatively easier because less math, but what the fuck do I know.

My alma mater was top 15 for comp sci and hard as fuck, lots of emphasis on low-level languages and assembly. You needed Calc I and II (this is almost universal), and one of either linear algebra or Calc III (multivariable) to finish math requirement. Then again my friend went to a shitty no-name school for comp sci undergrad, got a masters in cybersec from an online university and makes six figures at 27. He didn't know a fucking thing about Unix, low-level languages or assembly... he definitely took the """easier""" comp sci, software-engineering approach and makes ridiculous money.

So again, it depends on your school and where you want to go. If you want to understand the mysteries of computing you probably shouldn't go to a unranked school that teaches 99% practical skills. If you want to make money, or just get to work making programs, or God forbid to video games, the practical side of things might be your fancy (and this is not a bad thing, literally 90% of computer science majors end up in software anyway).

For example:
My school was mostly theory, we didn't even touch a GUI until 4th year, and just had to submit class/.c/.cpp files. If it needed a GUI one was usually provided. Whereas my sister went to community college and EVERY project had to have a working GUI.

another one, again I was pretty sure this is the right answer, can't see what i'm missing

Does anyone know where I can find a database for the pumping lemma for regular or context free languages? Something where it says the language and what word to pump...

>masters in cybersec

That's probably the reason why, the whole "cybersecurity" field is pretty much a money magnet now

Figured it out. This is bullshit IMO. ln(9(z-6)^5) should be exactly the same as ln(9*(z-6)^5). Who is in the wrong here?

You mean Young & Freedman?
What is your opinion on the Feynman lectures?

Ty user.
>I can elaborate on this significant difference if you'd like
Please do

>>pic related
How can i read that expression in pic.
its mean union of all element of U

this question is not for brainlets

please help brahs, I didn't buy the solution guide from the university jews

Think of it as like U_1, U_2, U_3, etc.

A is an indexing set, not necessarily the natural numbers.

How to show that

[math] \forall n. \ \forall (m