SQT

[Anonymous No.7512608]

StupidQuestionsThread! Get in Here and ask all stupid questions.
I'll start: My homework says that glucose, when metabolized, contains 17.2kJ/mol, which is obviously bullshit, right? (Same goes for Stearic acid @ 38.9kJ/mol and Alanine @ 17.2kJ/mol.) So, how many mol of Glucose, Alanine and Stearic acids do humans need to cover 7560kJ/day (17% Proteins, 30% Fat, 53% Carbs)? Thanks.

[Anonymous No.7512622]

how did it take time for time to come into existence without time?

[Anonymous No.7512625]

I wanna check if I've understood a question properly.

"Which three-digit number has three different primes as digits and is a multiple of all of these three primes? Factors may be repeated in the multiplication."

I said 735, because all the digits are prime and 5*147=735, 245*3=735, and 7*105=735.

Am I right, or did I misunderstand? With this sort of question, I would've thought they wanted something like a "and these three numbers are the entire prime factorisation of the three digit number"... so am I right or is my vocab fucked?

[Anonymous No.7512628]

>>7512608
not per mole, per gram

[Anonymous No.7512637]

0, 5, 17, 31, 49, 69, 93, what is the logic ?

[Anonymous No.7512638]

>>7512628
that's what i'm thinking too.
and do you possibly have an accurate source on metabolisis of Glucose? i found anywhere between 12kJ/g and 20kJ/g, do you have a more accurate range?

[Anonymous No.7512642]

Why don't girls like me?

[Anonymous No.7512644]

>>7512642
You're either ugly, incompetent, unintuitive, inexperienced or any combination of those.

[Anonymous No.7512662]

>>7512642
>>>/r9k/ to cry to
>>>/soc/ to also cry to but pretend you're attractive so you can fuck a lot of also ugly girls

[Anonymous No.7512663]

Are black holes tiny solid objects as i always imagined them?

Or are they gates to another dimension as Hollywood always imagined them?

[Anonymous No.7512669]

>>7512663
Black holes are tiny solid objects with a massive gravity. They bend light and spaghettify (yeah that's the real term) anything that comes close to them.

[Anonymous No.7512671]

What the cuck why isn't the answer 100

[Anonymous No.7512680]

>>7512669
Few days ago i heard somewhere that black holes are something like anti-matter particles, basically holes into the no-matter void that sucks in everything nearby.

[Anonymous No.7512719]

>>7512671
Look up how a cello works I guess.

[Anonymous No.7512722]

>>7512608
I'm starting my maths degree soon, how do I not get fucked into becoming a teacher?

Related, what the fuck is the different between finance, accounting and actuary?

[Anonymous No.7512775]

>>7512671
You wrongly assumed that the wavelength is 1m. If a standing wave is set up along the cello, this only constitutes half a wavelength (draw a picture to convince yourself). Thus, the wavelength is 2m, and the answer should be 50Hz.

[Anonymous No.7512866]

Change of base or something? (Need log form, no decimals)

[Anonymous No.7512890]

>>7512625
you're correct

[Anonymous No.7512894]

>>7512866
remember that <span class="math">log_b(x) = ln(x)/ln(b) [/spoiler]

this has to become a reflex.
any other weird manipulation is stupid and vain.

[Anonymous No.7512914]

I got given this question in an online tutoring session:

"solve for x and y;

2x + y - 3 + sqrt(4x -3y) = 19 + 2*sqrt(6)"

The answers were: x = 9, y = 4.

I couldn't solve it and got told that I wasted some kids precious time, even though we explored a different option. Oh well.

[Anonymous No.7512933]

why don't electrons fall into the nucleus? what keeps them in orbit around protons and neutrons?

[Anonymous No.7512942]

Is there any good article explaining the heat death of the universe in details? I can understand that <span class="math">\mathrm dU = 0[/spoiler] and <span class="math">\mathrm dS > 0[/spoiler] but not why it means that less and less things may happen.

[Anonymous No.7512967]

>>7512933
https://physics.stackexchange.com/questions/88441/what-prevents-an-atoms-electrons-from-collapsing-onto-its-protons
Tl;dr quantum physics.
http://education.jlab.org/qa/atomicstructure_08.html

Tl;dr we don't completely know

[Anonymous No.7512975]

>>7512933
also this:
In Modern Quantum Mechanics, however, the electron does not orbit the nucleus.

It is a standing wave (the wavefunction/state vector) around the nucleus; and it's energy levels are given by the Eigenvalues of the Hamiltonian:

Eψ= Hψ= iℏ*(∂ψ/∂t)

In QFT, again the same thing, the electron does not orbit; it's an excitation of the electron field determined by the Dirac Equation. The energy levels are given by:

E=√(1−α2Z2)
sorry, no idea how to use jsMath

sauce https://physics.stackexchange.com/questions/75225/what-causes-electron-to-orbit-the-nucleus-in-an-atom

[Anonymous No.7512995]

>>7512967
>>7512975
thanks darlings

[Anonymous No.7513009]

>>7512914
had a similar question in an oral exam a few years back, trying to remember how I solved it

[Anonymous No.7513039]

>>7512995
I was samefagging
:^)

[Anonymous No.7513077]

>>7512914
sorry but that solution isn't unique, is it ?
Are there any other constraints on x and y ? (as in they have to be integers or sth)

[Anonymous No.7513156]

>>7512914
for every variable you use, there has to be at least 1 equation to solve it uniquely(sry for shitty english). for this i have split it into 2equations, since there are 2 variables.
pic related

[Anonymous No.7513178]

Any medical technologists or clinical lab scientists? I got a degree in microbio and was wondering if I had a chance applying at hospitals. I understand there are specific degrees for technologists and you need to be certified or at least be able to become certified so I'm not sure

[Anonymous No.7513237]

Why does /sci/ hate string theory?

[Anonymous No.7513273]

when a current carrying wire induces a current on a nearby parallel wire, why does the current on the second wire go the other way as the current on the first wire decreases?

[Anonymous No.7513302]

>>7513156
you can't just separate terms like that...
>>7513237
because it's untestable

[Anonymous No.7513331]

>>7513237
They don't understand it, and probably never will.

[Anonymous No.7513336]

>>7513302
>untestable
Yet.

[Anonymous No.7513340]

>>7513302
sure, you can't do this, but why does it works perfectly in this case and what would be the appropriate solution?

[Anonymous No.7513341]

>my homework

Me: instantly reported for homework thread

[Anonymous No.7513349]

>>7513341
my textbook
better? it's not a hw thread.

[Anonymous No.7513352]

What weighs more? A kilogram of steel, or a kilogram of feathers?

[Anonymous No.7513360]

>>7513352
i dun ge' er?

[Anonymous No.7513363]

>>7513352
you're mother

[Anonymous No.7513372]

(3z)^2(6z^2)^−3 I need to simplify that and eliminate any negative exponents

I get stuck at this part

(3z^2)(6z^-6)

what do do after that.

[Anonymous No.7513392]

>>7513340
because you already know the expected solution so you just said "ok if we identify both parts it works"
But the solution is not unique, so the guy asking the question has ommited at least one condition on x and y.

[Anonymous No.7513401]

>>7512608
Is there a secret to infinite series and sequences... or do you just have to not be retarded? Because I can't figure this shit out and it's making me depressed

[Anonymous No.7513407]

>>7513392
>>7513340
to be more explicit, you can check that x= (3/10)(22+2sqrt(6)) and y=(2/5)(22+2sqrt(6)) is also a solution

[Anonymous No.7513432]

How was coulomb's law derived and confirmed?
Also, sources to experiments would be nice

[Anonymous No.7513455]

Why can't a set be a member of itself?

[Anonymous No.7513459]

>>7512975
Is this something taught in p chem? I'm taking p chem soon and can't wait

[Anonymous No.7513468]

>>7512622
>how did it take time for time to come into existence without time?

We honestly don't know, but as far as explanations go, there are only two possible scenarios with what we know now.

Whether the big bang started from colliding Branes, or whether the nature of the existence is a form of binary white noise that given an infinite amount of time produces the big bang and all the laws of physics as we know them, the process must take time outside of our spacetime. It may be that our spacetime is a bleed-through effect of that process, or a different kind of time entirely. But either way, nothing can happen, if no time can pass (as in, no movement of any particle, energy, or other variables, occurs).

The only other potential interpretation of the M-theory, then, is that there really is no time outside of our universe. Rather, if you look at a cyclic model within the M-theory, the universe (big bang and after, before everything ends) and the Branes are, have been and always will be tied to the same spacetime in a way. Basically, that theory predicts that dark energy has a function of spreading out all energy and matter to ultimately create an almost perfect uniform vacuum, and the more perfect that vacuum gets, the closer the Branes pull together. Until they collide, creating a new big bang again. In that sense, time itself is cyclic as well. And just as it's about to stop - if you will -, the church bell goes "ding" and it restarts again with a new big bang.

That's all just mumbo jumbo really, since evidently, we just don't know. But as said, time in one form or another IS a requirement for any change. So in essence those two scenarios, whether the physical reasons behind the scenarios have any reality to them or not, are the only viable explanation.

[Anonymous No.7513489]

>>7512608
If perception is limited to the physical receivers of the human body, how can a singular human being verify their surroundings, be completely certain of what is there and what is not there without the collective agreement of those around them?

I suppose its a stretched version of "If my brain is blind, how can I be sure what I am seeing is real, outside the knowledge I already have of the viewed subject?

I guess this is more of a philosophy question.

[Anonymous No.7513542]

>>7513372
You've already made an error by not taking the constants 3 and 6 to their powers.

[Anonymous No.7513560]

>>7512608
Can anyone translate/transcribe this? I got it as a congratulations card, but I can't fucking read most of it, was the guy trying to quote someone?

[OHP No.7513564]

>>7512637
Let P(n) be the nth prime, with P(0):=0. Then your sequence is just P(n) as n ranges over N.

[Anonymous No.7513569]

>>7513560
unreadable

[Anonymous No.7513570]

>>7513564
69 is not a prime though

[Anonymous No.7513576]

>>7513273
Because the second wire creates a magnetic field that induces current in the opposite direction on the first wire, reducing current on the first wire.

[Anonymous No.7513578]

>>7513560
>arithmatics, mathamatics, rheumalics or anyother matics, are all in the past to an advancad mathation from now on everything is

Fucking wat.

[Anonymous No.7513582]

>>7513578
>Fucking wat.
My thoughts exactly, I mean, it'd make sense if I knew what rheumalics is. Would it help if I said that the guy who gave me it was Scottish?

[Anonymous No.7513584]

>>7513578
it's probably a card from Jared Barnett, Jacob's retarded little brother
pic related

[Anonymous No.7513596]

>>7513582
I think it must be rheumatics, to keep every word ending with 'matics' (see how he forgot to cross the 't' in past).

I can't really understand what the message is saying though - perhaps, as one matures as a mathematician you start to appreciate the subject as a whole, rather than looking over its individual parts...

[Anonymous No.7513599]

>>7513582
I think rheumalics is his misspelling of rheumatics.

You said it was a congratulatory letter. Was it for graduating with a math degree? If so I think he saying you won't have to worry about learning or getting wrist cramps from writing anymore.

>>7513584
Kek

[Anonymous No.7513702]

>>7513599
>Was it for graduating with a math degree?
Pretty much.

>I think rheumalics is his misspelling of rheumatics.
Hmm, seems legit.

[Anonymous No.7513710]

I don't understand how to rearrange and simplify equations with fractions and what the rules for it are.
Like this equation: 3x/4=5(x+1/2).
I'm trying to solve this shit so I don't lose face while helping my brother but I have no idea. Can I get a pointer to the first step?

[Anonymous No.7513730]

>>7513710
>3x/4=5(x+1/2).
What is done to one side, must be done to another, or else the "equation" isn't "equal".
Multiple both sides by 4
3x=20(x+1/2)
Expand the bracket.
3x=20x + 10
Subtract 3x from both sides.
0=17x+10
Subtract 10 from both sides
-10=17x
Divide both sides by 17
x=-10/17
Hope that helps.

[Anonymous No.7513741]

>>7513730
The answer should be x=-5/7

[Anonymous No.7513747]

>>7513741
>The answer should be x=-5/7
It isn't, seriously, sub -5/7 in.

[Anonymous No.7513760]

>>7513730
It helps immensely and it checks out with the result of x = 0.588 I was stumped by the 4 and the parentheses and which one I should attend to first. Sincerely thank you.

[Anonymous No.7513770]

>>7513747
Did I enter the equation wrong? Or is the calculator wrong? Or me?

[Anonymous No.7513773]

>>7513760
>Sincerely thank you.
...I've done a good deed today. Fuck.

> I was stumped by the 4 and the parentheses and which one I should attend to first
There's no reason to attend to it in the order I've done, I just did that out of habit, I mean - you're gonna have to get rid of the 4 sometime, might as well do it first. "Fractions can go fuck themselves" is a good guideline.

[Anonymous No.7513782]

>>7513770
You've divided the right side by 2 for no reason.

[Anonymous No.7513796]

>>7513773
>Fuck
You can say that again because that's a great guideline to remember and I'll pass it on the next generation.

[Anonymous No.7513798]

What's the recommended chemistry software that can draw 2D molecules and export them as a vector format for linux? Pic related. The one I've found so far is BKChem.

[Anonymous No.7513799]

>>7513782
Plug them in and -10/7 gets two different numbers, while -5/7 make both sides equal to -.5357

[Anonymous No.7513860]

How do I deal with philosophy fags who think thier words can prove shit like platonic objects,God, dualism,etc

[Anonymous No.7513867]

>>7512625
They meant the number should be a product of its digits, so ABC = xA * yB * zC

Your numer is still right though, as 3 * 5 * 7 * 7 = 735

[Anonymous No.7513876]

>>7513860
You don’t. Philosophers are right indeed and you are just jealous because you are a fat lazy bastard who doesn’t want to read fascinating books that will make you smarter but prefer watching retarded popsci shows narrated by Morgan Freeman and calling it education.

[Anonymous No.7513907]

>>7513876
Found the philosopher

[Anonymous No.7513953]

What's on the go here? I've covered MVT a little (had to self learn) but this just looks fucked. What's it mean?

It's a step in proof of FTC1.

[Anonymous No.7513971]

>>7513953
> Curve F(x) passes through x_1 and x_2.
> There is a special point in between these, x_c.
> At this point the gradient is F'(x_c)=f(x_c) (f is just the derivative of F)
> The gradient is such that if you started from (x_1, F(x_1)) and moved away at a gradient f(x_c), you would hit (x_2, F(x_2))

[Anonymous No.7513976]

Is there any advice for anyone who was working through a maths book, had to drop it for a month and has now come back? I want to start where I left off, but I wonder if that's a bad idea.

[Anonymous No.7513982]

Could I kill my gut bacteria by drinking alcohol?

[Anonymous No.7513989]

>>7513971

Gradient?

[Anonymous No.7513994]

>>7513989
slope, steepness, dy/dx

[Anonymous No.7514299]

what do you recommend for a first course on linear algebra starting from vector/planes till eigenvalues and eigenvectos?

[Anonymous No.7514619]

very sure /SCI/ isnt for your home work b/c your to fuking stupid or lazy to do it yourself.

[Anonymous No.7514628]

>>7514299
"Matrices and Linear Algebra" by Schneider and Barker or "Matrices and Linear Transformations" by Cullen

[Anonymous No.7514711]

im going back to college for my second degree, and this time i need to take calc 2.

it's been over 4 years since i took calc 1 in my first degree. i remember how to find derivatives, and somewhat remember my trig functions. what else should i review? any good resources for a crash course on calc 1???

thanks and god bless.

[Anonymous No.7514748]

>>7513576
that doesnt really answer my question

[Anonymous No.7515169]

I'm trying to find c

a=b/(c/d)

Do I multiply d by (b/(c/d)) to cancel the d and the multiply d by a to get ad
OR
Do I multiply c/d by (b/(c/d)) to cancel out c/d then multiply it by a to get a(c/d)?

I'm confused.
If I did the first way, I feel I would get a negative or something.

[Anonymous No.7515221]

on my resume, under relevant coursework, should i specify whether or not a course was taken at the graduate level? seems like it would take up too much space/be too gaudy, but i've got a few grad courses on there and it might be helpful if employers new that

[Anonymous No.7515231]

>>7515169
your first attempt will fail because it won't cancel d.

You have trouble with b/(c/d).
what is 1/(1/2) anon ?

[Anonymous No.7515262]

>>7515231
2
I went for the second and got d.

Thanks

[Anonymous No.7515496]

How do I solve the following quadratic equation in <span class="math">\mathbb{R}[/spoiler] for <span class="math">x[/spoiler]?
<div class="math">x^2\cos\alpha - 2x\sin\alpha - \cos\alpha = 0</div>
The answer is supposed to be <span class="math">\frac{\sin\alpha \pm 1}{\cos\alpha}[/spoiler]

Thanks in advance.

[Anonymous No.7515514]

>>7515496
Never mind, I got it. The first few attempts I didn't pay proper attention to the quadratic formula.

[Anonymous No.7515588]

Hey /sci/, what are some good references for studying computational geometry? I'm reading de Berg et al, but some of the stuff just kind of goes over my head after a bit of reading. Specifically, interval trees and segment trees.

Also, I feel like I'm missing something when I read the book. What prerequisites should I have had to understand the concepts?

[Anonymous No.7516031]

>>7515221
bump

[Anonymous No.7516053]

I'm just throwing out my old college notes and I've noticed a question that I never got an answer to.

Excuse me if my question is imprecise, it's been years since I've even thought about this stuff...

Do we know that there's no algorithm that will always solve the Travelling Salesman Problem? Or is it just the case that we haven't found one? (i.e. is there a proof?)

[Anonymous No.7516874]

Help with trig. Replace cos^2 with 1-sin^2 or?

[Anonymous No.7516882]

>>7516874
<div class="math"> 3\sin^{2}(x)=1-\sin^{2}(x) \rightarrow 4\sin^{2} (x) = 1 \rightarrow \sin(x)=\frac{1}{2} </div>

I think that's what you want, but you've not actually asked a question.

[Anonymous No.7516893]

>>7516882
Solving for x.

[Anonymous No.7516900]

>>7516893
Then that's exactly what you want.

[Anonymous No.7516904]

Real quick guys, what is THE BEST most comprehensive textbook for P. Chem?

[Anonymous No.7516942]

>>7516053
bruteforce always works.
just take all possible paths and choose the shortest.
the problem is, that we don't have a good algorithm yet, that solves it for example in polynomial time

[Anonymous No.7516949]

>>7516882
you eliminated one solution in the last step
should be sin(x) = +-1/2

[Anonymous No.7517068]

100kPa - 27C
90kPa- C?

hELP

[Anonymous No.7517085]

>>7515514
>asks how to solve the thing
>solves the thing
>doesn't post way how the thing was done

[Anonymous No.7517086]

>>7517068
https://en.wikipedia.org/wiki/Ideal_gas_law

[Anonymous No.7517090]

>>7517085
>treat alpha as a constant.
>use quadratic formula
>solve for x

[Anonymous No.7517358]

>>7512642
>Why don't girls like me?

How many girls have you asked out?

[Anonymous No.7517362]

>>7512722
>I'm starting my maths degree soon, how do I not get fucked into becoming a teacher?
>Related, what the fuck is the different between finance, accounting and actuary?

Nobody wants to be an actuary + it is a very necessary job + it is very hard = makes Bank.

Many more people want to be in finance + it's not actually THAT hard, so they don't make a lot of money if employed, but can make MAD bank if running their own company.

Accounting is anywhere from meh-tier ("Accountant") to Bank ("External Consulting Auditor").

So:

If you want to start your own thing and are willing to accept a 90% chance of bankruptcy in return for a 10% chance of being Mr. Millions, go into the investment business.

If you want a guaranteed large paycheck, and you think you can hack it, become an actuary.

If you want a guaranteed OK paycheck with potential for doing your own thing later, become an accountant.

[Anonymous No.7517743]

So I moved to CU, and I'm working through the homework on masteringphysics for Physics II. Was a mathfag at my old university.

Is it common at these bigger name universities to feel grossly fucking underprepared for the homework? I've always been a pretty solid student. I usually keep up with everything. The examples were clear and concise, they didn't baby you so you still had to do work on the homework but it was more than reasonable, and it just worked.

I don't have this problem in any one of my other classes. (calc III for engineers is BS though because they don't prove shit) How do I combat this? I'm sick of having to internet my way through understanding on every problem. I briefly flipped through the textbook (which we are told we don't even need lmao) and it doesn't do much better of a job.

[Anonymous No.7517763]

>>7517743
As a mathfag myself I can tell you that it's pretty normal.
I usually sat around 5 hours on most of my classes per week with a couple of friends.
When I was TA for engineering and CS there was a lot of whining from the students about the workload even though they had to do less than the math students for the same credits.

[Anonymous No.7517787]

>>7517763
Any tips for working past this kinda thing then? I'm used to a mathematical approach on things. I had similar problems in physics I, but it seemed to me that everything was easily solved by a simple mistake in the middle of my work.

I don't think there's been a single question so far that I knew how to start. I can't keep this up the whole semester, I'll flunk the class. I don't mind workloads, I Just mind not being able to solve problems by myself. (shitty feeling) Only option to go in to the TA's hours pretty much all of the time?

[Anonymous No.7517808]

>>7517787
unfortunately I can't really help you much, since I'm also only used to the mathematical approach.
I minored in physics though but was never really good at it since I got lost in minor mathematical details that the professor just handwaved away or not even covered in the homework solutions.
Shit was infuriating.
But yeah. Going to office hours works. Working in groups also works, since you get a lot of different approaches / learn from others

[Anonymous No.7517946]

The really awful video lectures in my online Engineering Statistics class completely destroy my confidence in material I've just read in the book. How do I feel sure that I'm doing things right?

[Anonymous No.7517948]

>>7515221
come on nothing? i just want to know if i should make note of the grad courses i've taken on my resume

[Anonymous No.7517951]

Did the man who invented college go to college?

[Anonymous No.7517952]

>>7517946
Don't you guys have homework problems or something where you can check your level of understanding?

[Anonymous No.7517955]

>>7517951
https://en.wikipedia.org/wiki/Platonic_Academy
I guess...

[Anonymous No.7517956]

>>7517952
The thing about the homework is that you have to get 100% on an assignment to demonstrate competency. You have to enter them all and submit, and then you know if you got any of them wrong. If you didn't get them all right, you didn't demonstrate competency. You only get 2 or 3 chances per assignment.

[Anonymous No.7517963]

>>7517956
wow that sounds pretty shit.
homework should be there for people to get an understanding for the material and not to test knowledge

[Anonymous No.7517984]

>>7512608
glucose is 180.16 g·mol−1, so it's a decent amount of glucose we're talking about here. Your body isn't perfect at metabolizing it. I'm 100% sure nutrition isn't as simple as that.

[Anonymous No.7517989]

>>7517963
I agree. My vector calculus class has a much nicer setup. WebWork gives you unlimited tries on each problem, and is very good at parsing proper mathematical notation so you never get bullshit markdowns. The class also has access to Piazza, where students can ask and answer questions, and any professor teaching the class anywhere using piazza can also contribute.

[Anonymous No.7518000]

>>7517787

In physics you'll inevitably be faced with problems that you can't brute force through with the power of logic. Reality is complicated and the mathematics involved can be really esoteric even for some first year classical problems. The math that a first year physics student faces is something that mathematicians see at the master's degree level. This is why physicists have the 'mathematical methods of physics' -courses (at least in my uni). The proofs are largely left for the mathematics' department simply, because otherwise you'd major in math before physics.

You're supposed to get stumped on some problems. An average problem set for me so far has been 6-8 problems, out of which half are basic, 2-3 difficult and possibly one that requires what we refer to as 'the third eye'. This problem might hinge on some mathematical gimmick or approximation. The point is that you'll have to spend a few hours on the problem, discuss with a friend, ask for a hint or all of the above. This way when you finally get it, you're sure to remember it when you are eventually faced with a similar problem.

The third eye gets the sharper the more problems you work through.

[Anonymous No.7518013]

>>7518000 here

Just noticed >>7517956
My post is relevant only for sane universities, where the homework is returned in a group session, and checking the solution is a learning process just as much as doing it at home.

[Anonymous No.7518020]

Not the anon who posted >>7512914 but damn, I'd like to see an answer. I've been looking for an excuse to learn more stuff like that... does that even qualify as linear algebra?

Speaking of linear algebra, is it worth getting good at stuff like row operations? Or is it always better to just learn how to invert the relevant matrix? I remember that once I learned how to invert a 3x3 matrix, I quickly forgot how to solve equivalent things with row operations.

[Anonymous No.7518029]

>>7512642
There are billions of them out there, you haven't met the right one yet.
>>7512663
A black hole is the area around a singularity, which has a massive mass, density, and generates a massive gravitational force.
>>7512680
Nobody is sure really.
>>7513178
A lot of people from my environmental biology / ecology undergrad who did a lot of microscopy (TEM mostly) are working in hospitals now. I would think that if you have any sort of molecular experience you would have a chance. They will probably give you some kind of orientation for a while if you get a job in a hospital lab.
>>7513489
We simply can't be sure. Like every other living thing, human senses and the human mind are limited by biological constraints. We know our senses are based on some kind of real and pretty consistent physical phenomena, but once we look at what happens to those signals in the brain, we really have no idea.
>>7513798
I know there is a linux distro specifically for molecular biology and informatics, but I can't remember the name. If you look into that they probably have a list of the packages it comes with. One of them might be helpful.
>>7513982
I don't think it would be that dramatic, but it I'm sure a lot of it would change the community. The human microbiome is a hot subject right now so I'm sure someone has looked at it if you search enough.
>>7514711
khanacademy has calc 1 I think
>>7515221
If you give it the course number like XYZ 600 or whatever, the 600 (or whatever it is at your school) would probably let them know. I'm not actually sure if it's the same everywhere but I don't think its a bad idea to make clear that it was a graduate course.
>>7517956
That's sadistic I feel for you anon.

[Anonymous No.7518030]

>>7516942
>the problem is, that we don't have a good algorithm yet, that solves it for example in polynomial time
But do we know if such an algorithm exists? Or have we proved that it can't be done in polynomial time?

...have I just stumbled on P=NP?

[Anonymous No.7518033]

>>7517362
>If you want to start your own thing and are willing to accept a 90% chance of bankruptcy in return for a 10% chance of being Mr. Millions, go into the investment business.
>If you want a guaranteed large paycheck, and you think you can hack it, become an actuary.
>If you want a guaranteed OK paycheck with potential for doing your own thing later, become an accountant.
Seems legit, but what actually is the difference between those jobs?

[Anonymous No.7518037]

>>7518020
its not linear algebra since you have terms like sqrt(4x -3y) that make it nonlinear

here's your solution if you're still interested
http://www.wolframalpha.com/input/?i=2x+%2B+y+-+3+%2B+sqrt%284x+-3y%29+%3D+19+%2B+2*sqrt%286%29
shit get's messy
as for your question, I guess for inverting a matrix you need to use row operations.
I'm not really a fan of mindless calculations though, linear algebra is a nice starter for some higher level mathematics though with some really easy yet beautiful proofs

[Anonymous No.7518039]

>>7518029
>If you give it the course number like XYZ 600 or whatever, the 600
i just have it listed out like this currently. also might have a few too many listed, may take some out

[Anonymous No.7518044]

How do you remove glucosepane from collagen without damaging the collagen?

[Anonymous No.7518051]

>>7518030
Traveling salesman is proven to be NP-hard, so if P =/= NP there just can't be a polynomial algorithm.
For more you can just look up the wikipedia page

[Anonymous No.7518064]

>>7513860
>(dis)proving concepts as intractable as god
dude, just reverse troll them if you find them irritating and insert god into the question for them.

e.g. is the ideal god vishnu looking or does he resemble a greek philosopher
e.g. does the brain consider dualism, or dualisms in general, in two separate portions of the brain - what about the space the sends the signal between those two portions?

God. Sorry you're fucked. People who are 100% in their believe in god don't believe in objective thought, soooo.

[Anonymous No.7518065]

>>7518039
Hmm, maybe you can mention it in your cv? Or you could add a * next to the graduate courses and do a footnote, but I'm not so sure about that.

[Anonymous No.7518067]

>>7518065
>maybe you can mention it in your cv
im in US so we dont really do CVs
>you could add a * next to the graduate courses and do a footnote, but I'm not so sure about that
i thought about that but figured it would look a bit tacky

[Anonymous No.7518095]

How did you guys in your undergrad get involved with a professor's project/work?

I'm taking a data mining class and I want to do a lot more in the class, but I don't know how to approach this situation without seeming weird or something. On one hand, I understand if my professor would think of me as weird and tell me to sit down cause it's still the first week of classes. But at the same time I don't just want to be a student that comfortably sits in his chair for this class -- I want to be proactive with this course. But is it too soon, seeing as it's still the first week of classes for this class?

[Anonymous No.7518106]

>>7518095
You have to appear weird because only weird people will be willing to throw a bunch of time away for free ( where weird is abnormal not creepy ). Approach him with an email first regarding your interest in the class and your interest in his extra work. Take the extra time to craft a few buzzwords of interesting CONCEPTS relating to explicit areas of work he has been in. Defer to his knowledge in placing you ( i'm happy to help any way i can) but specify that you'd like to be a part of the process direclty if possible ( because of interest).

[Anonymous No.7518109]

>>7518095
It's honestly pretty informal in most places; try chatting with him about his work/projects in office hours or send an email showing your interest. Professors are at a University instead of a national lab to teach as a large part of their work--much of this includes teaching undergrads as well as grads/post-docs.

[Anonymous No.7518117]

>>7518109
I think you want to be formal from first reception just so they get a good impression. Meet when he responds positively to the email.

[Anonymous No.7518118]

>>7518095
http://colinpurrington.com/tips/lab-weasel
I was in the biological sciences, but I just was just sure to do well in this professors class and I talked to her after class one day and I went from their. Don't assume the professor will think you're a shitty undergrad or something, because that is absolutely not the case. Most likely they will be super excited that another person in the world thinks their work is cool. Even if you feel like you don't know how you could contribute, still make it known that you want to work with them.

[Anonymous No.7518119]

I tried making a thread for this but it didn't work.

I'm reading Probability Theory: The Logic of Science. It's kicking my ass. I could hardly follow the proof of Cox's theorems. Is this normal?

Also, the first real exercise asks: provide a formula for p(C|A+B) analogous to p(A+B|C) using the product rule and the sum rule. Is it possible?

I'm thinking it is, and the formula would be p(C|A+B) = p(C|A) + p(C|B) - p(C|AB), but I have NO idea how to prove this. Am I missing something? Shoulud this be intuitive?

Are there any rigorous but "slower" probability theory books out there?

>tl;dr I'm stupid pls halp

[Anonymous No.7518141]

Got some Malachite Green dye on my thumb in lab
Is there anything to help get this off faster or do I have to wait it out?

[Anonymous No.7518173]

>>7518141
It will come off eventually. Wear gloves next time.

[Anonymous No.7518238]

>>7512608
How much longer does the kid have to sit in the corner?

[Anonymous No.7518659]

Help with trig graphing. Starting with y=sin(x), what can I do to stretch or compress the line? Make the peaks and troughs higher/lower? Shifting left/right and up/down?

[Anonymous No.7518669]

>>7518659
when you have y=asin(b(x-PS))+VS

a is the amplitude, or the distance of the peaks/troughs from the zeros

2pi/b tells you the period
so if it was sin(2x), then the period is 2pi/2=pi, and you're compressing the graph horizontally, hitting the zeroes and peaks/troughs twice as fast

ps is how much left or right you're shifting it

vs is how much up/down you're shifting it

[Anonymous No.7518694]

>>7512608
This is as common mistake. Calories on your cereal box are 1000x less that the actual calorie used in measurement. We need a lot more than 7560 kJ a day...

[Anonymous No.7518707]

I'll fucking try this again.
does p(C|A+B) = p(C|A) + p(C|B) - p(C|AB)?
If so, what's a paraphrased version of how to prove it?
pls halp?

[Anonymous No.7518912]

>>7518707
if you wanna try again, why don't you tell us what the fuck A B and C are (random numbers ? sets ?)

[Anonymous No.7518919]

What is a solid and preferably objective website(s) that lists college graduate programs by rank in the U.S.?

[Anonymous No.7518947]

>>7518919
I wouldn't trust any of those websites to be honest.

You can use them as a starting point to filter out some unis, but you should always check out the website of their faculties.

For example a university might be ranked highly in mathematics, but then all they do is statistics, while you want to get involved in abstract algebra - so this would not be a good solution for you.

University rankings are mostly an indicator for how many papers a university publishes and not really for the teaching they offer.

[Anonymous No.7518951]

>>7518707
If this is just simple probability (which I'm pretty sure it is, from what I remember), then that seems right to me.
Might want someone who's done probability within the last ~3 years to help you with proof, though.

[Anonymous No.7518953]

>>7518947
Hm alright. Was mainly trying to obtain some form of metric to judge potential places I would like to apply to in the future. Thanks for the feedback, anon.

[Anonymous No.7518976]

Should I use tert-butyllithium to light a Bunsen burner?

[Anonymous No.7519008]

>>7518976
>Search it ti look at properties
>Links for several pages are already purple
That was... disconcerting.

I don't have an answer, it just scared me enough to post.

[Anonymous No.7519098]

Whenever i rotate my foot my ankle/heel cracks, it is painful when it happens, why?

[Anonymous No.7519222]

>>7519098

Consult an orthopedist.

[Anonymous No.7519235]

>>7519098
Is it time to list all joints you can crack?

>All finger joints (3 for each finger, including thumbs)
>Both ankles
>Jaw very occasionally
>Spine slightly more often
>Neck
>Middle three toes, sometimes big toes
>Knees
>Elbows
>Wrists

[Anonymous No.7519341]

Can a Wilcoxon sum rank test be used on data sets that are "tied".

e.g. survey scored from the same individuals at two separate times. So the people in sample one are the same people in sample 2 but with different survey scores.

Does this violate the independence assumption of this test?

[Anonymous No.7519371]

>>7519341
Also I'm not sure if tied is the correct term here. I'm not talking about when the data have ties in determining greater than/less than; rather, the two samples are the same sample but at different time points, so each data point in one sample is linked to another point in the other sample.

[Anonymous No.7519530]

I have a question about notation.

When I'm doing integrals, I write the original problem, then I write my substitutions or by-parts info, then when I go back to rewrite the integral I'm putting an arrow ----> before it to say "which implies" or "which leads to".

Is this correct use of the right-pointing arrow in this context?

[Anonymous No.7519550]

>>7519530
pic please, maybe we can give you more advice than you think :)

[Anonymous No.7519551]

Self studying QM, I covered the intro stuff (dirac notation, operators etc.), now I'd like to see it applied on something. I've seen that the "must do" examples are the 1-D quantum harmonic oscillator, the infinite potential well and finite potential well.

If you guys have some resource (books/notes) to suggest me for studying these topics, I'd appreciate it a lot.

[Anonymous No.7519557]

>>7519530
Just write it out.
"Here I use the substitution
_____
which leads to
_____"

A single lined arrow can have different meanings depending on context (for example in a function definition) so if you want to use it you should define what it means first.

I've seen some people use it in the way you want to, but never a professor

[Anonymous No.7519575]

>>7519557
The problem is I don't want to put an = sign because what proceeds it on the page is not equal to it.

If I had to use a symbol, what should it be?

[Anonymous No.7519577]

>>7519557
The problem is I don't want to put an = sign because what precedes it on the page is not equal to it.

If I had to use a symbol, what should it be?

[Anonymous No.7519579]

>>7519575
now I'm not even sure if I understand your problem correctly
do as >>7519550 says please

[Anonymous No.7519581]

>>7518912
They're logical propositions to which a certain degree of "plausibility" can be assigned. So...neither?
>>7518951
It is simple probability, but I'm a simple idiot.

[Anonymous No.7519590]

>>7512608
/fit/ here

>(17% Proteins, 30% Fat, 53% Carbs)

1990 called, they want their meme dieting back

>not 70% proteins, 20% fat and 10% carbs

[Anonymous No.7519610]

>>7519577
POST PIC FFS, WE DON'T UNDERSTAND WHAT YOU WANT TO SAY.

[Anonymous No.7519660]

>>7519590
>not 50% protein, 30% fat, 20% carbs
your brain needs energy you dumb faggot

[Anonymous No.7519878]

Chances of transferring to UC San Diego or Irvine as a Computer Engineer without doing the Physics courses? I'm a Mexican.

[Anonymous No.7519888]

>be me
>have a hard on and penis starts to hurt
>had to go in the college bathroom just to masturbate
>20 minutes after fapping and penis doesn't hurt anymore

What happen to me, /sci/?

[Anonymous No.7519909]

>>7519888
You're the protagonist of the source to this image

[Anonymous No.7519913]

What about the CYP enzymes cause them to mutate at a higher rate than other enzymes in the body

[Anonymous No.7519923]

im an idiot, pls go easy on me

if I let S_k be the kth partial sum 1+1/2+...1/k, how would i prove with induction that
S_(2^i) < 1+ i for all i >=1?

[Anonymous No.7519936]

>>7519878
I'm a San Diegan, UCSD is pretty prestiguous but it's definitely easier to transfer than get in normally (I don't go there but I got accepted for EE). Fuck UC Irvine you go there if you're an autist who doesn't want to talk to anybody.

And idk, physics is pretty fucking important for computer engineering so you best hope you get it done.

[Anonymous No.7519992]

I have two columns of data in a csv.

Is there a way to use excel, libreoffice, or some other tool to take the derivative of one with respect to the other?

[Anonymous No.7519996]

>>7519992
that makes no sense at all

[Anonymous No.7520000]

Is the NoFap method actually backed by science? Does it have a plausible explanation?

[Anonymous No.7520001]

>>7519992
>>7519996
One of the columns records pressure, the other temperature. I would like to be able to graph the derivative of one with respect to the other against other quantities.

[Anonymous No.7520004]

>>7519923
Assume true for n:
<span class="math">S(2^n)<1+n[/spoiler]

Consider n+1:
<span class="math">S(2^{n+1})=S(2^n)+\frac{1}{2^n+1}+\frac{1}{2^n+2}+...+\frac{1}{2^n}[/spoiler]

Now,
<span class="math">\frac{1}{2^n+1}+\frac{1}{2^n+2}+...+\frac{1}{2^n}<\frac{2n}{2^n+1}[/spoiler]

i.e. the first term is the largest and there are 2n terms. This will satisfy the weaker, but still true, inequality that:

<span class="math">\frac{1}{2^n+1}+\frac{1}{2^n+2}+...+\frac{1}{2^n}<1[/spoiler]

Thus, if the first equation is true, then:
<span class="math">S(2^{n+1})<S(2^n)+1[/spoiler]
<span class="math">S(2^{n+1})<(n+1)+1[/spoiler]

And so, if it is true for n, then it has been shown to be true for n+1. Finally we must test this for n=1:

<span class="math">S(2^n)=1+\frac{1}{2}=\frac{3}{2}<1+1[/spoiler]

Thus, since it is true for 1, it is true for 2, 3, 4, 5, 6....

[Anonymous No.7520009]

>>7520001
(p2-p1)/(T2-T2)

[Anonymous No.7520018]

>>7519996
Can you read?

>>7520001
I'm sure there are pre-existing derivative functions in excel, but it's not difficult to code it yourself if you're happy with small error:

> Start a new column, C, to keep the derivative values for your variables stored in columns A and B
> Select the first cell in C (say row 1).
> Enter the function "=(A2-A1)/(B2-B1)"
> Drag this function across all of column C

It is possible to reduce error by taking more clever combinations of your A and B cells, but this should do for now.

[Anonymous No.7520019]

>>7520000
>Is the NoFap method
What method?

[Anonymous No.7520026]

>>7520004
how are there 2n terms? and also why does S(2^n) + 1 become (n+1)+1?

[Anonymous No.7520042]

>>7520026
Sorry, there should be <span class="math">\frac{2^{n}}{2}[/spoiler] terms. This would make:

<span class="math">\frac{1}{2^n+1}+\frac{1}{2^n+2}+...+\frac{1}{2^n}<\frac{2^n}{2(2^n+1)}[/spoiler]
and so:
<span class="math">\frac{1}{2^n+1}+\frac{1}{2^n+2}+...+\frac{1}{2^n}<\frac{1}{2(1+2^{-n})}<\frac{1}{2}<1[/spoiler]
...a bit untidy, I suppose.

S(2^n)+1 becomes LESS THAN (n+1)+1 because we have assumed to start with that S(2^n)<1.

[Anonymous No.7520043]

How do I calculate the 4,000,000th Fibonacci number without crashing my computer?

[Anonymous No.7520047]

>>7520043
Courtesy of based Stephen Wolfram:
http://www.wolframalpha.com/input/?i=4000000th+fibonacci+number

[Anonymous No.7520051]

>>7520009
>>7520018
Thanks. I was hoping there might be a lower-error method, but this should be good enough.

[Anonymous No.7520054]

>>7520051
Argh! In my previous post, I should have said:
S(2^n)<n+1

Anyway, no worries, give it a solid read through, I guarantee errors...

[Anonymous No.7520063]

>>7520042
thank you for clearing this up for me :D

[Anonymous No.7520067]

Sorry
>>7520051

But
>>7520054

Was meant for
>>7520063

[Anonymous No.7520072]

>>7520051
To reduce error, use: https://en.wikipedia.org/wiki/Finite_difference_coefficient

[Anonymous No.7520079]

>>7520042
wait, in the second inequality, is it meant to be ( 1 / (2(1+2^(-n)) ?

[Anonymous No.7520083]

>>7520079
seems fine to me, just divided top and bottom by the numerator

[Anonymous No.7520087]

>>7520083
yes, i am an idiot

[Anonymous No.7520088]

I want to work with hardware like robots/metal gear. Is computer engineering the way to go?

[Anonymous No.7520104]

How long should it take you to read and understand a ~100 page long scientific paper with some math? Like for example a computer science one.

[Anonymous No.7520263]

Following pemdas or bedmas the following:
7-3+2
Should equal 2 right?
Why the heck is it 6?

[Anonymous No.7520267]

>>7520263
ayy lmao

[Anonymous No.7520281]

This was taking from wolframalpha. It shows it equalling six.

The only possible explanation I can come up with is that addition and subtraction are applied at the same time. Left to right.

[Anonymous No.7520285]

>>7520104
one or two or three weeks

[Anonymous No.7520311]

>>7520263
BO(DM)(AS), as in the brackets you just do whatever comes first in the equation.

[Anonymous No.7520335]

>>7513468
>The only other potential interpretation of the M-theory, then, is that there really is no time outside of our universe. Rather, if you look at a cyclic model within the M-theory, the universe (big bang and after, before everything ends) and the Branes are, have been and always will be tied to the same spacetime in a way. Basically, that theory predicts that dark energy has a function of spreading out all energy and matter to ultimately create an almost perfect uniform vacuum, and the more perfect that vacuum gets, the closer the Branes pull together. Until they collide, creating a new big bang again. In that sense, time itself is cyclic as well. And just as it's about to stop - if you will -, the church bell goes "ding" and it restarts again with a new big bang.
not the anon you were addressing, but 10/10 for the post.

>almost perfect uniform vacuum
there is a different level of vacuum at different parts of the universe? this is the first i've heard of this, but i bet gravity is involved somehow. i'd appreciate any knowledge you have of this matter - in return; pic related, which i hope pleases your autism, as it does mine.

[Anonymous No.7520470]

>>7518119
Your stupid you need halp

[Anonymous No.7520472]

>>7519878
Orange countyan here. UC Irvine is indeed trash and for fucking autists or people who just want to party with daddy's money

[Anonymous No.7520480]

>>7520335
>there is a different level of vacuum at different parts of the universe?

What the fuck is matter

[Anonymous No.7520571]

Best scientific calculator on osx?

[Anonymous No.7520663]

How can you prove if your solution to a logic problem is the optimal?(e.g. the secretary problem)
Is there an algorithm that can definitively prove it?

[Anonymous No.7520710]

Ideas for a bachelor project?
Team consists of an energy engineer and a programmer.

[Anonymous No.7520854]

Should I go for IT or physics engineering?

[Anonymous No.7521218]

I have a professor who's test is mostly just homework problems for Math. Is this good or bad?

[Anonymous No.7521334]

>>7520004
>>7520042
I think you have a mistake in both of these.

There should be 2^n terms but the last term should be 1/2^(n+1), the way you wrote it it's larger than the first one

[Anonymous No.7521387]

I asked a question in a new thread. I am not sure how stupid it is but I will link to it from here just in case.

>>7521369

[Anonymous No.7521458]

I have a degree in microbio and I'm looking for jobs in hospitals. Some of the jobs say


"Bachelors degree in Medical Technology or Clinical Lab Science or equivalent Science"

I know med tech/clinical lab have their own degrees but does "equivalent science" include micro or does it mean something completely different?

[Anonymous No.7521461]

What is the difference between singular homology and simplicial homology?

[Anonymous No.7521872]

dP/dt = kP-C
I'm working through homework for Diff Eq, and I'm supposed to answer a) does a bifurcation occur as the parameter C varies? and b) Describe the long-term behavior of the population P(t) if P(0)>0.

I've decided there is no bifurcation, by saying that the graph of F(x) = kP is just a line, so moving it up and down (-C) won't add or remove any equilibria.

The second part is bugging me. Wolfram says the solution is P(t) = ce^kt + C/k
This makes no sense to me. If C >= kP, shouldn't the population decline or (in C = kP) stay constant?

If I put in kP for C in the previous equation, I would get P(t) = e^kt + P, which doesn't make any sense at all. I've been doing great in this class until this section, and it seems like something I'm going to have to deal with a lot, so if someone could explain it to me, that would be great.

[Anonymous No.7521906]

>>7521872
C is a constant, so you writing C >=kP or C = kP (where P is a fucking variable function) is a little weird.

[Anonymous No.7522013]

hey /sci/ real quick

Can I pull a negative out of the cross product on the right? I can't find anywhere that says i cant, but im not good enough with vectors to be sure

These are standard basis vectors

[Anonymous No.7522060]

Trying to solve this minimum spanning tree for Op Research class.
Easily solvable thrugh algorithms, but I can't think of the linear restrictions to solve it in excel.

halp?

[Anonymous No.7522081]

>>7522013
yes you can pull any number out except 0

[Anonymous No.7522104]

>>7521906
I mean, if C ever happened to be greater than kP (like if a pond had ten fish, but you took fifty out), then you would have a negative P, which would change the direction of the graph, right?

[Anonymous No.7522109]

>>7522081
thanks

[Anonymous No.7522157]

If the universe is billions of years old and everything interesting is light years away, does that mean the chance of us (the human race) EVER finding life outside earth is insanely small?

[Anonymous No.7522169]

>>7522013
no, but you can remove the negatives, imagine it with the right hand rule: when you point in front of you and to the left, the cross product is up. When you point behind you and right the cross is also up

[Homeostasis No.7522192]

Hey /sci/, got a problem that I don't quite understand how to solve. So for Calc 2, I'm required to do homework on MyMathLab and I came across a problem on Total Distance traveled.

Lemme give you the important shit.

v(t) = 4cos(2t) on the interval [0, 2π]

Positive on: [0, π/4], [3π/4, 5π/4], and [7π/4, 2π]

Negative on: [π/4, 3π/4] and [5π/4, 7π/4]

So, I already know that I need to use absolute values in order to find the total distance for ∫ |v(t) dt on [0, 2π] BUT, that will take up too much time to calculate and too much space. Couldn't I just integrate v(t) from [0, π/4] and then multiply the result 5 times as opposed to calculating the whole damn thing?

[Anonymous No.7522231]

>>7522192
Yes, you could

[Anonymous No.7522295]

>>7522104
C can never be greater than kP because :
kP = c*exp(kt) + C

that would mean c*exp(kt)<=0
which is not possible if you want the population to not be negative forever.

[Anonymous No.7522316]

>>7513468
this and all of science is moot because there can be no objectivity without at least some subjectivity for conscious beings, thereby creating an impenetrable wall of understanding.

in other words, we can never know the answer.

maybe skynet will

[Anonymous No.7522317]

help pls

[Homeostasis No.7522320]

>>7522231

Hey anon.

I did that but my answer was 10 whereas the answer for MyMathLab was 16. I spent like a good 30 minutes trying to figure it out and it didn't really work at all.

I'm most likely doing something wrong but I don't know what.

[Anonymous No.7522385]

>>7512608
what's powering atoms? What makes electrons constantly orbit them?

[Anonymous No.7522757]

Inverse help. Need x^2 +2x -1 for when x> 0.

[Anonymous No.7522871]

>>7522385
The nucleus has a positive charge, electrons have a negative charge. This keeps the electrons near the nucleus.

You're under the misconception that electrons orbit atoms like planets orbit the sun. This used to be what everybody thought, and is still a good way to describe it to people new to the subject. However, this would mean the electrons would have to lose energy to stay away from the nucleus, and every atom would be emitting radiation. Quantum mechanics explains it better. Electrons are attracted to the nucleus, but they tend to be found in specific orbital shells: http://physics.stackexchange.com/questions/9415/why-do-electrons-occupy-the-space-around-nuclei-and-not-collide-with-them

[Anonymous No.7522872]

>>7522157
No, but we don't know the probability that life exists yet. The light years shouldn't hold us back

[Anonymous No.7522882]

>>7522295
I think I got it, thanks. As long as P(0) > C/k, the population will increase.

[Anonymous No.7523032]

Hi.

Is there any way to factor this without using the quadratic formula?

20x^2 + 23x + 6= 0

[Anonymous No.7523091]

>>7523032
No, I don't understand why you wouldn't.

[Anonymous No.7523098]

>>7523032
notice -3/4 is a root
polynomial division
but I personnally wouldn't test -3/4 as an "obvious solution".

[Anonymous No.7523104]

Why is hydrogen peroxide unstable. as far as i can tell HOOH has sufficient bonds and electrons,
hydrogen has a valence of 1, oxygen a valence of 2, they each have that same number of bonds and as far as i know they all fill the octet rule where the O's would each have 2 lone pairs?

[Anonymous No.7523110]

>>7523104
nevermind i think i figured it out. It's technically stable, not electron deficient or anything with respect to its composition, but its MOST stable state is a spontaneous decomposition reaction into water, because H2O and O2 has more entropy than H2O2

[Anonymous No.7523118]

>>7523110
okay i'll extend this question actually, how can i look at H2O2 and know that its oxygens are not in their most stable state? something something oxidation number, i don't know how that works.

[Anonymous No.7523211]

>>7521218
>I have a professor who's test is mostly just homework problems for Math. Is this good or bad?
Depends, what are you studying?

[Anonymous No.7523223]

>>7522757
Should be easy...
Let y=x^2 + 2x -1
Complete the square
y=(x+1)^2 - 2
y+2=(x+1)^2
sqrt(y+2)=x+1
x=sqrt(y+2)-1
So,the inverse is sqrt(x+2) -1

[Anonymous No.7523226]

>>7523211
homework science

[Anonymous No.7523231]

>>7523211

Math.

[Anonymous No.7523233]

>>7523032
>Is there any way to factor this without using the quadratic formula?
>20x^2 + 23x + 6= 0
Like >>7523098 said, you'd have to notice one of the roots, which probably wouldn't occur by trial and error, unless you're using the sign change rule (or the mean value theorem or whatever it is that Americans like to call it). However, if you're familiar with iterations (if you're not, look it up - I genuinely enjoy Newton-Raphson more than porn), then you could find the root that way and continue to do long/polynomial division. However, if you are familiar with stuff like this, chances are that you know the quadratic formula by heart, so I don't know why you'd do it any other way.

[Anonymous No.7523234]

>>7523211
>>7523231

Calculus III to be specific

[Anonymous No.7523239]

What engineering degree would most likely help work on the hardware side of engineering instead of the software side? I want to work on tanks, robots, weapons, or just computer parts.

[Anonymous No.7523245]

>>7523231
>Math.
Then its fine, practice really does make perfect, and you tend not to be confident with anything mathematical until you've had some practice, so if the test is just like the homework, then you should be ok, because in theory - understanding and proficiency of/with the material is a prerequisite to do the homework, so if the test is just like the homework, then the test should succeed, because any good maths test should test proficiency and understanding which your tests are clearly doing.

[Anonymous No.7523262]

>>7523032
>>7523233
Well... actually, you could factorise it...
(ax+b)(cx+d)=20x^2+23x+6
bd=6
6=1*6 or 2*3 (since the coefficient of x is an integer, I'd be pretty confident that b and d are integers)
ac=20
20=1*20 or 2*10 or 4*5.
ad+bc=23
Good fucking luck, but it is theoretically possible and with enough experience, I'd reckon you'd be able to do it quite quickly.

(tip: don't try to solve the above algebraically, you'll just find yourself back at the original quadratic)

[Anonymous No.7523292]

>>7519888
phimosis and dry foreskin

[Anonymous No.7523294]

>>7523032
Complete the square. Which is really kind of to say learn why the quadratic equation works.

[Anonymous No.7523304]

I was thinking of applying to a CSU in October, but I don't think I have a shot since I don't have Physics I and II done. Do you guys think CC counselors would have an idea if I have a shot? I was thinking of going to one and ask, but I don't want to waste my time.

[Anonymous No.7523360]

>>7523294
>Complete the square
He said factor, not solve, but fair play I guess, since you could solve then factor it.

[Anonymous No.7523392]

>>7523360
but it literally implies factoring first...
20x^2 + 23x + 6 = 0 is equivalent to
20x^2+23x + (23/(2sqrt(20)))^2 = (23/(2sqrt(20)))^2 -6

which is the same as
20x^2 + 23x + 529/80 = 49/80
or
(sqrt(20)x + 23/sqrt(80))^2 = (7/sqrt(80))^2
you can then put everything on the same side and factor

[(sqrt(20)x + 23/sqrt(80)) - (7/sqrt(80))][(sqrt(20)x + 23/sqrt(80)) + (7/sqrt(80))] = 0

you can remove the sqrt(20) to simplify this a lot if you want

20*[x+16/40][x+30/40] = 0

[Anonymous No.7523400]

i want to find the antiderivative of f(x)=x+a using substitution. why am i fucking up this? i know i could just use linearity, but i don't get why this is wrong:

substitute u=x+a, so we have du=dx and
∫(x+a)dx = ∫udu = u^2/2+C = (x+a)^2/2+C

but if i used linearity i'd have that the antiderivative is x^2/2+ax+C. what am i doing so wrong?

[Anonymous No.7523403]

>>7523400
maybe you should look into the boundaries of the integral...
if x goes from 0 to t, u goes from a to t+a

[Anonymous No.7523444]

>>7523400
(x+a)^2/2+C
=(x^2+2ax+a^2) /2 + C
a^2 /2 is a constant
So, (x^2 + 2ax) /2 +C
Which is x^2/2+ax+C as required.

[Anonymous No.7523448]

>>7523360
If you think of solving and factoring into linear terms as two distinct things, then you need to get back to studying polynomials.

[Anonymous No.7523455]

I made an IQ test on “IQ research” online.

Got a result of only 128, and now I am feeling like a piece of crap.

Is this IQ enough for me to achieve something in life if I continue to put effort on it?

[Anonymous No.7523460]

>>7523455
>only 128
Fuck off.

[Anonymous No.7523469]

>>7523460

But isn’t this result bad for the /sci/ average? According to the site it is a very gifted result, superior to more than 96% of the population. But I keep seeing people here stating that they made serious IQ tests and got results like 145 and 150. At least people here say they have IQ’s of 135-137.

I really felt inferior compared to most guys here on /sci/. I don’t know if a) they were being insincere, b) they made bad-quality tests or c) the average intelligence of people here is actually pretty fucking great.

[Anonymous No.7523471]

>>7523455
better cut on your carbon footprint and commit suicide now you trash.

[Anonymous No.7523477]

>>7523469
>But isn’t this result bad for the /sci/ average? According to the site it is a very gifted result, superior to more than 96% of the population. But I keep seeing people here stating that they made serious IQ tests and got results like 145 and 150. At least people here say they have IQ’s of 135-137.
You must be new, /sci/ doesn't give a shit about IQ.

[Anonymous No.7523512]

>>7523477

Yes, I’m new on this board.

But I feel inferior when compared to people who are really gifted in logic, mathematics and physics.

I always had great linguistic abilities (English is not my first language, tough), and won a lot of prizes during my 28 years of life. I have published my first book last year and am now working on other projects. I was also capable of modeling, drawing and painting from an early age.

Yet I always admired the sciences, so much more because mathematics seem to me a strange dialect, untamable hieroglyphs and strange signs that my brain simply can’t chew. Verbal textures can be tamed; you can sculpt their body like clay, but mathematics… I just see the numbers and symbols as laughing crows on the page: they mock me for being unable to decipher them. My grades at school were terrible, to the point that I almost flunked on 2-3 years of high school.

That’s why an IQ score of 128 seems really low to me, especially because I see you guys discussing mathematics and proudly bellowing super-high IQ’s. I feared to take an IQ test for a long time. But well, I guess I can still write good books if I continue to devout a lot of my time to writing.

[Anonymous No.7523517]

>>7523512
Ok, please, take this from someone who's knows what they're talking about.

Practice makes perfect.

I'm not intelligent, even in my reports from school my maths teachers would say stuff like "I hope he takes no offence to this, but he's not the most gifted in the class".

All you have to do to get good at maths is practice, seriously, it's basically a language, practice it and you'll learn it.

Stop tricking yourself into thinking that it's beyond you, get a fucking textbook or website or whatever and do it.

You'll not be a Gauss, but believe me, you can get really fucking good at maths just from practising.

[Anonymous No.7523526]

>>7523517

Will do that.

I write my literature in the mornings, and work from noon to 6:00 pm.

When I got home I will start to slowly study mathematics, for myself, to satisfy my curiosity. I guess that the absence of pressure upon your shoulders makes any learning activity much more pleasurable.

[Anonymous No.7523533]

>>7523512
>mathematics… I just see the numbers and symbols as laughing crows on the page: they mock me for being unable to decipher them. My grades at school were terrible, to the point that I almost flunked on 2-3 years of high school.
math is ill-defined bullshit until you build everything from first principles. that's why high school math classes are for fags. we need kids to learn zfc in kindergarten

[Anonymous No.7523614]

>>7523460

So an IQ of 128 is actually high if you do a real test?

Lel, I wonder how fake are those websites that list the “surprisingly high IQ of celebrities”.

[Anonymous No.7523625]

>>7523614
>So an IQ of 128 is actually high if you do a real test?
I don't get how people don't understand this.

By definition 100 is average.
128 is above 100, so it's above average.

[Anonymous No.7523628]

>>7523614

The actor James Woods is supposedly the happy owner of a 180 point IQ brain, and yet what are his amazing contributions to high demanding sciences or supreme artistic achievements?

[Anonymous No.7523646]

i have basic algebra problem so you have f(x+h) -f(x)/ h you all know that newtons quotient thing and you want f(x)= 6

so 6+h-6/h so you get h/h. The book says the answer is zero but I thought it was 1. Like a number divided by same number is always 1. WHAT THE FUCK

[Anonymous No.7523651]

>>7523646
maybe because it's not 6+h-6 but 6-6.

[Anonymous No.7523718]

>>7523646
I'm going to need you to define f(x). If f(x)=6 for all x, then f(x+h)=6.

So, f(x+h)-f(x) always equals 0.

[Anonymous No.7523730]

>>7523718
I don't understand why would you ignore the h? Isn't (6+h) saying 6 plus a really small number? Its not the same as 6 by itself. Or is it?

[Anonymous No.7523741]

>>7523730
>I don't understand why would you ignore the h? Isn't (6+h) saying 6 plus a really small number? Its not the same as 6 by itself. Or is it?
Define f(x), if you've said that f(x)=6 for all x, then you're saying that for any input to the function, I'll get 6, so f(3333)=6, (f3334)=6, f(your mother)=6, so f(x+h) is no different.

[Anonymous No.7523794]

Mechanical or Electrical undergrad for Nuke graduate?

[Anonymous No.7523846]

>>7523794
Electrical

[Anonymous No.7523858]

Bowl I contains 6 red chips and 4 blue chips. Five of these 10 chips
are selected at random and without replacement and put in bowl II, which
was originally empty. One chip is then drawn at random from bowl II.
Relative to the hypothesis that this chip is blue, find the conditional
probability that 2 red chips and 3 blue chips are transferred from bowl I to
bowl II.

[Anonymous No.7523862]

Please someone help me, I don't understand how I'm doing this problem wrong.
3/5x - 2 = x - 1/2
I just don't understand how I'm doing this wrong.

[Anonymous No.7523875]

>>7523862
What exactly are you trying to do? Solve for x? Also, please reformat into a less ambiguous equation, i.e. is that (3x)/5 or 3/(5x)?

[Anonymous No.7523878]

I want to ask about a radio wave in space.
Does it go on forever if it doesn't hit anything?
Does it suffer some kind of degradation on it's own?

What about a photon?

If these things go on forever, how does entropy apply?

[Anonymous No.7523882]

>>7523875
Yeah I'm trying to solve for x, and the 3/5 and the 1/2 are fractions.

[Anonymous No.7523891]

>>7523862
>3/5x - 2 = x - 1/2
Solve?
3/5 x = x + 3/2
-2/5 x = 3/2
x=3/2 * -5/2
x= -15/4

[Anonymous No.7523990]

I feel like I don't have enough information to solve this problem, thoughts?

Show that the sequence {a(sub n)} is a solution of the recurrence relation a(sub n) = -3a(sub n-1)+4a(sub n-2) if a(sub n) = 0.

I can't even generate values since i only have a(sub n) and the recursion needs 3 elements..

[Anonymous No.7523999]

>>7523990
>Show that the sequence {a(sub n)} is a solution of the recurrence relation a(sub n) = -3a(sub n-1)+4a(sub n-2) if a(sub n) = 0.
Use fucking TEX.

[Anonymous No.7524002]

>>7523999
I couldnt find anything saying how to use tex on here, could you tell me how

[Anonymous No.7524009]

Show that the sequence
{<span class="math">a_n[\math]} is a solution of the recurrence relation <span class="math">a_n[/spoiler] = -3<span class="math">a_{n-1}+4a_{n-2} if a_n = 0.[/spoiler][/spoiler]

[Anonymous No.7524016]

Show that the sequence {<span class="math">a_n[/spoiler]} is a solution of the recurrence relation <span class="math">a_n[/spoiler] = -3<span class="math">a_{n-1}[/spoiler]+4<span class="math">a_{n-2}[/spoiler] if <span class="math">a_n[/spoiler] = 0.

[Anonymous No.7524025]

>>7523846
Would I be considerably behind if I went with Mech?

[Anonymous No.7524033]

>>7523999
I feel like I don't have enough information to solve this problem, thoughts?

Show that the sequence {<span class="math">a_n[/spoiler]} is a solution of the recurrence relation <span class="math">a_n[/spoiler] = -3<span class="math">a_{n-1}[/spoiler]+4<span class="math">a_{n-2}[/spoiler] if <span class="math">a_n[/spoiler] = 0.

I can't even generate values since i only have a(sub n) and the recursion needs 3 elements..

[Anonymous No.7524145]

>>7520019

That thing about not fapping and quitting porn for about three months, in order to regain lost sexual energy.

[Anonymous No.7524211]

>>7524145
Give this a read http://www.yourbrainrebalanced.com/index.php?topic=15558.0

[Anonymous No.7524345]

Why do some people say pure math and philosophy are closely related?

[Anonymous No.7524360]

>>7524345

Because both are completely useless.

[Anonymous No.7524509]

>>7512608
Is it true that non-Americans say Mathsematics? I think that they do because the say Maths instead of Math.

[Wikipedia.org No.7524522]

>>7524360
[Citation Needed]

[Anonymous No.7524544]

>>7524345

Pure math based on logic. Making logical and usually symbolic statements, based on axioms. Same with philosophy.

[Anonymous No.7524559]

>>7523741
this guy explain good

>>7523646

i try explain too. you have f(x) when you change f(x) to f(x+h), look at the f(x) and replace all the x's with x+h instead. if f(x) = 6, then try to do f(x+h). ok go look at all the x's in 6. replace them with x+h. well there were no x's so nothing gets replaced. it stays just as 6.

[Anonymous No.7524640]

>>7519577
=> Is what I use. Stands for implies.

[Anonymous No.7524748]

How can i become a Data Analyst?

I'm comfortable with my programming skills.

I have a dataset for 2013 and 2014. Since I'm just a noob, would it be wise to use the 2013 data to predict what would happen in 2014? So if I get it right, then I'm on the right track. But if I get it wrong, then I need to keep working on it?

Also, is there like a typical formula for analyzing data?
Like
>gather 2013 data
>clean the data
>plot the data
>apply linear regression
>plot the data along with linear regression
>???????
>u have predicted 2014

What would the ??????? be?

Thank you all.

[Anonymous No.7524962]

Is the number of roots of a polynomial function always equal to its degree (factoring in the multiplicity of each root and also considering complex roots)?

[Anonymous No.7525422]

>>7524509
>Mathsematics
I'm British, it's mathematics or maths.

[Anonymous No.7525423]

>>7524962
>Is the number of roots of a polynomial function always equal to its degree (factoring in the multiplicity of each root and also considering complex roots)?
Yes.
https://en.wikipedia.org/wiki/Fundamental_theorem_of_algebra

[Anonymous No.7525657]

What are the theological implications of evolution?

[Anonymous No.7525901]

>>7512622
Time is a phenomena caused by energy, which is movement itself.
The universe just kept being contaminated with energy since the big bang (before it was just unmoving matter )