/sci/ - Science & Math

Hi, brainlet here.

Prove that [math]|\sin(t)|^{-1/p}[/math] is of weak [math]L^p(\mathbb{T})[/math]-type. Definition: [eqn]|\{t:|\sin(t)|^{-1/p}\leq \lambda\}|\geq 2\pi -C\lambda^{-1/p}[/eqn] for some [math]C[/math] and all [math]\lambda>0[/math], or equivalently (the one that I tried to use):
[eqn]|\{t:|\sin(t)|^{-1/p}\geq \lambda\}|\leq C\lambda^{-1/p}[/eqn]
I tried: if [math]|t|\leq \lambda^{-p}[/math], then
[eqn]|\sin(t)|^{-1/p}\geq |t|^{-1/p}\geq \lambda[/eqn]But this only shows that [math]|\{t:|t|^{-1/p}\geq \lambda\}|\leq |\{t:|\sin(t)|^{-1/p}\geq \lambda\}|[/math], but I want the reverse inequality.
I also tried [math]\frac{2}{\pi}|t|\leq |\sin(t)|[/math] to obtain [math]|\{t:|\sin(t)|^{-1/p}\geq \lambda\}|\leq |\{t:K|t|^{-1/p}\geq \lambda\}|[/math] with [math]K[/math] some constant, but this only holds for [math]|t|\leq \frac{\pi}{2}[/math], so I cannot prove anything for the other [math]t[/math].
Chebyshev/Markov doesn't work either, since you need it to be in [math]L^p(\mathbb{T})[/math], while it's not.

Please help me out. Thanks

>>9780218
for some reason tex broke for me weird

>>9780227
Did you let it load long enough? It may differ for different deviced I believe. Else you could try if it works on some other device.

Should I do a major in Math with a compsci minor, or a joint compSci-math degree?

>>9780309
the latter obviously.

Are the molten forms of metal like iron reflective like the solid forms are? If you could somehow strip away the blackbody radiation and just look for reflected light, could you see a mirror-like surface like you sometimes get with mercury?

How much physics is there in a chemistry degree? Could I practice physics after a chemistry degree? UK, btw.

>>9780405
Thermodynamics, electromagnetism, and some basic quantum mechanics. But ot depends on what kind of chemistry you're doing. My research lab involves semiconductors and catalysis, and we coordinate with the physics department to study the magnetic properties on our lettuce structures.

>>9780474
*Lattice structures

How am I supposed to determine the potential here?

>>9780526
C=e*A/d=Q/dV

>>9780541
I know, but how do you find Q? Also isn't it Q=CV?

>>9780526
I think you have to consider x as the separation distance and then let z,y be the area.

>>9780541
wait, I think I got it. I take the negative gradient of V, and then since D dot n = surface charge density, and the surface area of the charge is given as 80 cm^2, I can get Q on each plate, right?

Is it possible there are statements which are true but cannot be proven? I have some inequalities and numerically they're obvious, but they involve some nasty equations so I don't think they are possible analytically.

>>9780779
>Is it possible there are statements which are true but cannot be proven?
https://en.wikipedia.org/wiki/G%C3%B6del's_incompleteness_theorems

>>9780786
This was disproved already. Stop baiting, assclown.

>>9780216
Neat pic

I guess thats what it would look like if today if there were still other hominids hanging around

test

What are the best resources for a beginner learning Anatomy/Physiology?

I'll be taking an analysis midterm in a couple of hours. It is about differentiability in finite dimensioned normed vector spaces. Anything I should know? Any neat exercises you can suggest? I'll be reading my textbook.

I've been working on this for quite a while, and I realize we can find an a such that f(a) < c and a b such that c < f(b), but I don't know how to show that a is less than b to construct a closed set to use the intermediate value theorem on.

Any hints?

>>9781180
Use your hypothesis of both L's being limits.

Is there any way to increase the quality of my reading? At this point I have to read a chapter 2 or 3 times before I can do the exercises.

>>9781194
I used that hypothesis and set the epsilon = L^+ - c, and the other epsilon to c - L- or something like that

Not sure where to go from there

Have our assholes grown dependent on toilet paper over time, or did people just have to deal with constant rashes before it was invented? What about apes and monkeys and such? Do they need to wipe?

>>9781180
Notice that all you are being asked to do is extend the intermediate value theorem to the extended reals.

I would proceed by taking any sequence [math] p_n [/math] that converges to infinity and [math] s_n [/math] that converges to negative infinity. This is so that [math] f(p_n) [/math] gets arbitrarily close to [math]L^{+}[/math] and [math]f(s_n)[/math] approaches [math] L^{-} [/math]

Now you need to consider some cases. I will just consider the cases [math] L^{-} < c < L^{+} [/math]. Now all you have to do is find a way to bound [math] f(s_{k}) < c < g(p_{n}) [/math] and then apply the usual intermediate value theorem.

To do this, you may proceed by contradiction. Suppose that for all [math] k, f(s_k) \geq c[/math] . Then taking the limit as [math] k [/math] goes to infinity, [math] L^{-} \geq c [/math] which contradicts our original inequality. The same happens with [math]p[/math].

To have a full proof you have to actually argue all the cases (or sufficiently argue for a WLOG free pass). And at the end of the day you will learn a valuable lesson in analysis: Everytime you are asked to extend a finite theorem to an infinite context, it will 99.9% of the time follow from taking some kind of limit and applying the finite cases simultaneously.

>>9781201
Not really, you’re already doing the right thing by going over it until you get it. It will get easier as your understanding increases, but then it will get harder as the material becomes more difficult. Stick with your work ethic and you’ll rise quickly. Maybe try writing down your thoughts as you read or mentally summarizing after each paragraph.

>>9781238
I'm a little confused how to formalize the first part of this.

Here's what I currently have:

We know that [math] \forall \epsilon > 0 \exists \exists N a > N \rightarrow |f(a)-L^+| < \epsilon [/math] so I plugged in epsilon = L+ - c, and therefore, c < f(a). I did something similar with f(b) < c, and now I'm a little unsure what to do.

I was thinking of using the definition of (epsilon-delta) continuity and I showed that there's some x and some delta such that if |x-a| < delta, then f(x) < epsilon + c, but that doesn't help with anything yet.

>>9781296
>>9781238
>>9781208
>>9781194
>>9781180

I think I figured it out now.

I set a = max (N1 + 1, N2)
and b = min(N2 - 1, N1)

where N1 is the N1 from the definition of the limit with the L+ (i.e., the one with x > N1 --> |x - L+| < epsilon) and N2 from the negative infinity one.

Then, a < b, and f(a) < c < f(b)

I believe this should be valid enough to use IVT on

I read about chemistry mistakes and found this.
>Condensed liquid oxygen or solid argon with liquid nitrogen. (A mistake you only make once.)

What do they mean? I tought oxygen and nitrogen are condensed both out of air?

>>9781345
http://chemistry.mit.edu/department-resources/environmental-health-safety/safety-notes/liquid-nitrogen

apparently it explodes (oxygen) or explodes in a different way (argon)
which is in line with everything i've heard from chemists because most chemistry stories end with either a huge cloud of something bad or an explosion

When a bottle of ice water accumulates condensation, is it actually dehumidifying your room?

Can I get some help on this, /sci/?
So I'm pondering bullets. From what I'm reading, the mass of bullets is so low, what really counts is muzzle velocity/the energy of the shot.

I would've thought that the weight/composition of the bullet was more important than just the power behind it. The tendency for the object in motion to stay in motion. A weightier projectile should be harder to make fuck off and go richochette over there.

Is this true? Are modern bullets so light that it's really more damaging to just make them move fast as possible?

And, I was reading wiki. About launch velocity to get things into space. What they effectively did to get something the size of a bullet to escape velocity was fill a bag with hydrogen and ignite it to make it punch an object like a hammer, with enough force that it could conceivably escape earth's gravity and go into space.

Have we reached some sort of physical ceiling as to how powerful we can make standard sized bullets? Where we either need to make them full of more powder, or full of a new more powerful kind of powder?

Should I pick a STEM major even when I’m not smart or interested in particular anything?

https://www.wolframalpha.com/input/?i=Piecewise[{{1,+-3+<%3D+x+<%3D+-1},+{x^2,+-1+<+x+<%3D+2},+{2x%2B2,+2+<+x+<+4+}}]

Function anon from yesterday you here?

When I'm describing this function and describing the range y > 0 would it be correct to say

y > 0 when X ∈ [-3;0) and (0; 4)
OR because the function is not continuous, I have to define the range separately i.e.
y > 0 when X ∈ [-3;0) and (0; 2] and (2; 4) since we technically do not have y = 5

Its really hot. Can I freeze water bottles and put them in my room to cool it? Keep in mind the freezer is in another building.

How do I know if I did well in interview?

>>9781840
>Its really hot. Can I freeze water bottles and put them in my room to cool it? Keep in mind the freezer is in another building.
Yes
Another cheap method is get steel buckets and fill them with cold water and place around in the room.

This will cool things down and make air moister

>>9781842
>How do I know if I did well in interview?
They will actually call you back.

>>9781849
I can't wait that long, man. I'm getting anxious about the results.

>>9781817
There's nothing wrong with the first statement. Clearly [math]y>0[/math] when [math]x \in [-3,0)[/math] and [math](0,4)[/math]. It doesn't matter that the function doesn't get the value 5 in these intervals since you're only looking at whether it has value greater than zero.

Also that graph is slightly misleading. It suggests the function has value 0 outside of the interval [math][-3,4)[/math], when the function isn't even defined outside this interval.

>>9781858
Okay, thanks!

As for:
> Also that graph is slightly misleading. It suggests the function has value 0 outside of the interval [math][-3,4)[/math], when the function isn't even defined outside this interval.

beats me, man, wolfram is weird

I'm trying to make an AM radio receiver circuit that's fairly similar in principle to pic related. I've constructed the circuit but the sound being produced isn't audibile unless I hold my ear to the speaker and even then I can't make out what is being produced. You're meant to be able to hear the sound clearly and loudly.

Does this indicate a problem with the values I've chosen for the resistors and the capacitors, or does it indicate some other problem with the circuit? I'm not sure but I would imagine that a problem with the resistor and capacitor values (which produced the desired result when simulated in LTspice) would produce a loud sound but static instead of clear audio, which leads me to believe that it's something fundamentally wrong with the circuit I made.

Are LED's safe for health? I find studies with contrasting results and many of the people who made them seem like they could have some conflict of interests.

>>9782374
What amplifier is the circuit using? Is it capable of driving the speaker? Most of the other common mistakes would show up in the SPICE simulation.

>>9782765
It turned out to just be an issue with the audio jack adaptor. I used a different one and now I'm getting loud static but I guess that just means there's a problem with the values I've chosen.

Prove -a = (-1)*a

?

Can someone explain when I'm allowed to use Gauss's law, and Ampere's law, and when I'm not.

How do I tell if I'm Jewish with science?

>>9780216
I got a question relating newtons third law. if I pick up an item with a specific weight, am I exerting 9.8 acceleration* mass on that item so that it will counteract gravity?

So if x-rays are barely attenuated by air, doesn't that mean that if one pointed a powerful x-ray tube into the distance people 1km away could still receive a (very small) dose?

If you pick up an object, you are exerting the objects mass*g ONLY if that object is at rest in your hand, I.e. your applied resisting force would have to be constant (in acceleration). In reality, your applied acceleration would vary since your hand is constantly in motion. An appropriate example for this concept is the block resting on a desk. The desk is exerting an equal and opposite force (in magnitude and direction) aka the normal force to the object's applied force on the table (weight (m*g)). Since the table, and the the block on the table are both at rest, the table is "exerting" a force equivalent to the acceleration due to gravity (in the direction opposite to weight) * the mass of the object.

>>9783355
thanks a lot for the explanation, so from my understanding the table is moving -9.8 acceleration specific to the mass, to counteract the 9.8 acceleration that gravity is exerting on to it.

>>9783144
Not possible

I realized that something I typed up should really be done in set notation, can someone link me to a quick resource so I know what professional notation should look like

I'm basically handling things within certain boundaries but I realize it's really stupid to keep referring to larger set/physical set etc, help a brainlet

Why do people hate real analysis but like complex analysis

>>9783422
What did you type up?
>>9783167
haplogroups

We can't truly understand how quantum mechanics work, right? But then how are quantum computers made?

>>9783490
basically just optimizing a sort of nasty function on a weird boundary, it turned up in my undergrad project and I presented a solution but the language is really clunky

Trying to calculate the angle with tan(ima/real)
And I get two different angles because of the "-".
Can you tell me which one of these is correct?

Does any complex genius know why for any holomorphic function [math]f[/math] with [math]f\neq 0[/math] in the simply connected domain [math]D[/math] has that (any branch of) [math]\log(f)[/math] is holomorphic?

Some guy tells one needs to use the Monodromy Theorem, but does this mean that [math]\log(f)[/math] is single-valued on [math]D[/math]? And how do we even know that we can analytically continuate [math]\log(f)[/math] to all of [math]D[/math] only by means of a small disk?

>>9781783
yes

>>9783498
badly
they are made badly and have many problems
they are not ready for prime time usage

Is a quantitative analyst's job (I know there are different kinds) more exciting than an actuaries? Or are they both equally boring? I know this can be very subjective.

Is there any video or article or something that manages to describe something advanced in mathematics in a way that a non-mathematician could understand?
Some grad school stuff or maybe late undergrad. It's in order to help me figure out if I really want to do mathematics, I like early university level stuff but I can't really imagine doing the advanced stuff.

>>9784089
do you know the chain rule?

>>9784158
I would guess that it's more fun but it also seems to vary too much to say.
From what I read in job ads, I think it could be fun to be a quantitative analyst.

>>9784331
exciting yeah
very stressful though, and not because the work itself is particularly hard

>>9784357
If it's not stressful because of the difficulty then what makes it stressful? I am assuming hours, deadlines and expectations although I think the last one would translate into the job being more difficult at least in terms of logistics. I know you can't really just choose but in an ideal world I would like to be a quantitative researcher or work in model validation.

I hope finance isn't as boring as I think it will be, I just want to get into this since I have connections in the financial world (+ I live in NYC) and because the only thing I am good at is applied math.

>>9783373
Really? Is the prove not possible?
>>9783144

so gravity varies depending on height, what's gravity like at the deep of the ocean? does it ever get to 10 m/s^2?

>>9784879
Gravitational force depends on how far you are from the center of the mass, the further the less power it has however, it also depends on density.

>>9784911
Yes, i'm asking how strong is gravity's acceleration at the bottom of the ocean

>>9784917
pick a weight to calculate

>>9784917
Not much stronger.
Pressure differs from gravity btw

>>9784326
Hell yes: [math]\frac{f'}{f}[/math] is holomorphic and so is its primitive. I already know how to analytically continue the thing thanks to the dude.

Can we conclude now that [math]f(D)[/math] does not circle around [math]0[/math]? (Else [math]\log[/math] would not be continuous/holomorphic)

>>9783487
It's a meme. But it is true that both have different flavors, with complex analysis being very rigid and in a sense a lot more "algebraic" than real analysis. Basically, being holomorphic is a lot more restrictive than being R-differentiable, hence holomorphic functions have spectacular properties that are not shared by typical differentiable functions (fundamentally analyticity).
That being said, it makes no sense to hate one or the other since they are both, at least at a basic level, necessary for a well-rounded mathematical education, and are both interesting and fun in their own right.

>>9783487
>>9785233
Well, I would say that real analysis is rather analysis of spaces of functions (usually metric spaces), while complex analysis is more focuses on the functions themselves and their properties (like holomorphic etc.).

The first is something that doesn't scare True Mathematicians at all, while brainlets get more easily BTFOd by those kind of more abstract things, while complex stuff may be more intuitive.

>>9782498
No, you should not eat any LEDs

>>9783183
Hi, OP here.

Not a physicist, but I can reason. You are talking about weight (mass measured on Earth): if you are on Earth, then yes. Draw a hand stretching out with a block of lead and draw the arrow pointing down with mass x 9.8 Newton next to it. You hold it still, which means that you exercise exactly that amount of Newton. If you do it in space, then no, because the acceleration is not 9.8.

If you change the formula to "Newton exercised = weight x 9.8", then it's a yes on Earth and a yes in space (because there the weight is somewhat 0).

>>9783183
>>9785296
I should also add that you exert more force when you lift it up than when you pick it up sideways (ignoring the energy from regular arm movements), since in the first case you give the object more gravitational potential energy.

>>9784588
it's not NOT difficult, but it doesn't stand from any other mentally engaging job in a significant way. that's fine, you should be over the "what i do is important because it's difficult" delusion by now.
my friend is/was a quant trader. he loved the job and the work itself, and his coworkers were pretty great too. he also loved loving in the city. however, he told me that you only get time off when the markets are closed.

yeah, that's what makes it stressful. some people love it. my friend quit his job and is now traveling and trading on his own time. personally, i prefer my job where i'm allowed a little more time off and i can think about a much larger swathe of things during the workday.

>>9781799
What you mean to say is that the force which stops a bullet is predominately air resistance rather than gravity, meaning that the shape of the bullet is a greater indicator of its trajectory rather than its mass.

>>9784917
g = G*M / r2

>>9784917
[math]
g = \dfrac{G \cdot M}{r^2}

you need to estimate what portion of earth's mass is left, when reducing r

>>9784917
[math]
g = \dfrac{G \cdot M}{r^2}
[/math]

you need to estimate what portion of earth's mass is left, when reducing r

>>9785313
Thanks a lot anon. And I don't buy into that delusion, I just wanted to know what made it stressful.

I'm trying to learn type theory, so first I'm trying to understand the differences between ZFC and ETCS. So I stumbled across the definition of the natural set. ZFC looks very straight-forward but ETCS looks like I'm missing something. They define [math]\mathbb{N}[/math] as having an element 0 and a function [math]s: \mathbb{N} \rightarrow \mathbb{N} [/math]. It is trivial that s has closure, but what in the name of fuck does it do?

I want to learn python.

Please give me good tutorials. Preferably without all the BS about "how to download and install durr". I'm not a complete retard.

>>9785577
https://docs.python.org/

>>9785577
>>>/g/

>>9785583
Thank you.

>>9785564
Anyone. I'm too dumb to understand it. And I don't want to look like an idiot asking this to a professor. I only want to harass them when I have a better more complex question.

>>9785602
post on stackexchange

How do I stop being a NEET? How do I find motivation to search a job?

>>9785603
Just asked, if anyone is interested in the answers: https://math.stackexchange.com/questions/2806118/natural-set-construction-with-elementary-theory-of-the-category-of-sets

I made a chart on excel with the x axis on log 10 scale, but when i get an equation of the line of best, the x term is in fucking natural log. Why???

>>9785644
>how do I stop being lazy and do productive things?

Start small. Set a really small goal for yourself and just do it. Your body will release dopamine afterwards and you'll feel good. Keep doing it every day and eventually you'll be addicted. It's not even being productive anymore, it's just another drug addiction, and those are easy to acquire!

ANSWER MY QUESTION

>>9785731
Because 10-log is for fags and natural log is Real Mathematics. All fag-logs need to be eradicated from our planet.

What is /sci/‘s favorite si unit?

I'm never doing a group assignment again. What are some ways I can get out of them?

>>9785872
Im measuring on the x axis the 10 fold difference in molarity of chloride on a pH meter, i cannot have the linear trendline tell me the equation of the line be y = m ln(x) + b

>>9786066
surely you know that [eqn] m\ln(x) + b = \frac{m}{\log_{10}(e)}\log_{10}(x)+b [/eqn]

mathematica is a joke, don't fall for the hype
you have to google everything and hope you're not doing anything out of the norm so you can find examples
very poor documentation

how the fuck do you get a list of vertex coordinates of some shape, for example how would you make a box/rectangle and get {{-1, -1}, {1, -1}, {1, 1}, {-1, 1}} without having to type the coordinates manually

Is the [center of mass] of an object defined as the point where the average distance from every other point of the object is the lowest?

>>9786305
No.

>the point where the average distance from every other point of the object is the lowest?
Maybe, that is true if the object as a constant density, but this is a very vague definition, you can define it purely mathematically.

>>9786308
But wouldn't [higher density] just mean that there are more points in that area, though?

>>9786312
>But wouldn't [higher density] just mean that there are more points in that area, though?
You generally do not model a large objects in that way, at least mathematically that is nonsense.
If you are talking about atoms, you still need to weight, so No.

should i study maths or physics? (at ntnu in trondhjem)

maths is more interesting imo but physics feels safer regarding future employment

>>9786719
>future employment
>maths or physics
shiggy

i need an acoustic signal that covers the range from ~100kHz to 1MHz and is reproducible, any ideas?
i was looking at some piezo elements but they have a pretty small frequency range and i would need at least 100kHz steps, but finding those turned out to be not so easy.
around 1 Mhz you can find some mass produced chinese stuff but they want to sell in large quantities which i do not need.
could a mechanical impact work? like dropping a ball bearing onto a steel plate?

>>9786719
no offense but what are you planning to do with either of those besides becoming a teacher

>>9781853
Build a time machine then.

I need eigenvectors and values for this matrix.

Now in mathematica when I input it using wolfram language it gives out what I ellipsed in the top.

But in the same fucking notebook using wolfram alpha input it gives a completely different result!

What the fuck?

And my result is different from both of them:
Eigenvalue being quadruple 1 and vectors being:
{1, 0, -2, -4} (actually same as the upper wolfram result multiplied by -1) and {0, 1, 1, 2} - which you cannot get by multiplying the wolfram vector.

So what the fuck is going on here? Can anybody help me out here?

>>9780216
Where can I watch a good lecture on Euclidean algorithm?

>>9780216
Whats the best resource to learn the equivalent of a math degree assuming they don't even know Calc 1? Online resource that is.

>>9786986
some sort of research, development or something like that

>>9787099
you could look into computer science, computer engineering, mechanical engineering

>Prove that any timelike vecor U for which U^0>0 and U*U=-1 is the four velocity of SOME worldline

What the fuck does this even mean? Jesus I can understand not putting emphasis in mathematical rigor, but what the fuck is this shit? Sorry, having problems with latex.

>>9787062
look at what you entered

>>9787200
nvm iuno

How do i develop the habit of studying?

a short backstory: i only studied on the days before tests at school and it worked most of the time (except for mathematics and physics), but now that i'm in college that doesn't work anymore so i'm doing terribly bad in every single course. When i try to study i get easily distracted and 5 minutes of studying feels like forever. So i want to know if there is a method for studying or something that will help me develop the habit of studying.

I'm about to fail an upper division course

How absolutely and utterly fucked am I for grad school

>>9787519
Take a W

>>9787297
Sit in the library. Turn off your phone. After a few hours go smoke some weed and chill out for half an hour. Go back in and study more. Works for me.

Cramming only gets you so far and even if you CAN study the night before and pull an 80, you can be pulling all As with dedicated daily studying.

>>9787581
I can't
I have one more week in the quarter and I'm gonna fail because it's an EE course, and my parts for my final project got delayed in their arrival
i should have placed the order a week beforehand, fucking hell

>>9787595
You still can. Ask the professor to give you a WU grade. Take the GPA hit temporarily, then write an appeal letter saying you were depressed so they change the WU to a W. Theres always recourse

>>9787599
We genuinely don't have WUs, though the next best thing would be an incomplete, which I know the professor won't give me since he's failed students who have been in the same scenario as me.

I just don't think that F is unavoidable. My other 7 upper div classes are As, except for one C+ which I got my first quarter, and I'm probably gonna keep getting As, save for this blunder. Am I basically fucked, then?

>>9780309
The latter

>>9781201
Take notes as you read, do it sectionally, IE. Read the part of the chapter regarding one type of problem, practise that problem, then go one with the chapter.

Highlighters are bullshit and don't help you any more than just a reread, anything done by highlighting is done x1000 by note taking

Can someone tell me how to solve this with the method of Newton-Raphson?

>>9787621
An F is pretty bad, so is a C for grad school. I would bust ass and do everything you can to finish the project and try to get a C

How do you prove the second part of this? Analysis genius required

>>9787708
Well I'm fucked
goodbye academia
at least I might still be able to find work.

>>9787881
Honestly what do you even need to go to grad school for? A bachelors in engineering is sufficient. I know people who had 2. somethings get hired. Maybe you wont get into grad school right away, but industry experience can make up for past poor performance.

>>9787879
From 1 you know the function is bounded outside [-a,a], so you just need to check for that inteval, which is closed, so the function obtains a maximum in this interval cause the function is continuous.

When did we figure out planets were worlds? Like when was it discovered that those little dots in the sky were actual tangible places? I'm pretty sure the question is poorly formulated, but I hope you guys get the idea.

Can a source/collector of solar energy in space send energy to something else in space? Google only gives me sites about through the atmosphere which is retarded

>>9787958
>send energy wirelessly (is it exclusively electromagnetic?)

>>9787959

>>9787685
No

>>9787685
Do you even know what Newton-Raphson is?

You literally just fill in the function in the algorithm. What did you try?

Can someone explain this? This book fucking sucks

Can hurricanes generate a small amount of radiation under the right conditions?

>>9788383
nevermind I got it thanks to youtube, the book still fucking sucks though.

When i start reading any science book my eyes and head begin to hurt after 10-15 minutes. I can’t concentrate because of that since childhood times. Am i just vaccinated adhd retard? Does anybody know how to fix that problem?

How do I stop playing video games? I am a casual gamer who never touches video games during the academic year but during vacation I can spend up to 2 hours a day playing Gundam Breaker 3 or SRW. How do I stop playing video games altogether? I feel like I could get some work done in that time instead of building some shitty mobile suit.

>>9788479
You're probably farsighted anon, sometimes you won't notice actual blur because people with hyperopia can actually compensate for their lack of "focus". Go to a optometrist. That's how I found out I was farsighted in highschool, I thought I had ADD too. I'm a sophomore now and my vision has actually gotten much worse maybe because I still never wore my glasses because I didn't really buy the whole thing... But now everything up close is blury for me so I will probably go to the eye doctor pretty soon.

https://www.health.harvard.edu/vision/farsightedness-hyperopia

>>9788611
2 hours a day and only doing it when you're on vacation seems pretty damn healthy to me. Trying to be productive 100% of the time is just going to wear you out, having something for fun is fine as long as it's not your whole life.

If you really want to stop, just go cold turkey, sell/donate/uninstall everything. If you can go the whole academic year without playing games, you have enough self control to get rid of them if you really want to.

>>9780789
I didn’t know Godels theory of incompleteness was disproven?

If it actually was, please direct me to where I can read about it.

>>9783144
I can’t

>>9783144
follows trivially from the uniqueness of additive inverses

>>9786164
s = []
v = [-1, 1]
for i in v:
for j in v:
s += (i, j)

Alternatively, a mapping of {0, 1, 2, 3} to what you want, is
f(n) = {(n % 2) * 2 - 1, (((floor(n / 2)) % 2) * 2 - 1)}

>>9783144
Add a to both sides.
LHS:
-a + a = a - a = 0
RHS:
(-1) * a + a = a + (-1 ) * a = (1) * a + (-1) * a = a * (1) + a * (-1) = a * (1 + (-1)) = a * 0 = 0

>>9788777
>mathematica

>>9788832
and mathematica is supposed to be more expressive and intuitive than normal programming languages. it would be something like Rectangle[1] // List or whatever but there doesn't seem to be anything, no one at wolfram research thought of such a use case, even though you need to specify texture coordinates to overlay a plot over an image for example

>>9787906
The magic word the professor is looking for here is “compact”

kinda /sci/&/his/ here.
Does anyone know how constellations are described on this ?
Like Ursa maior 2
Or Aquila
It seems to have a link with ptolomean classification but I'm not sure.

I’m having such a hard time deciding what major I should study
I was honestly never good at any science subject at school, if not for he security of jobs I’d choose something like history and literature

>>9780216
how do billionaires having publicly known email addresses get to read their email messages? They are supposed to get a lot more shit messages from real people than normal people get spam

So I was given these two questions for my discrete math class

1) How many Boolean functions that are total are possible?
2) How many Boolean functions are possible?

I answered 2^2^n to the second question, because the domain of the function counts 2^n combinations of the input variables, and for every combination you can freely assign 0 or 1.

But according to my professor that's the answer to the first question, not the second one. I still have to answer the second one and not sure what to do.

Please help.

>>9789280
If you're not interested you will be miserable and fail. I was more interested in history/humanities too, but i ended up liking some math, and am now i math major. a lot of science is hard work - you need to be able to memorise loads and think hard about problems (some majors have more to be memorised). If you are interested, but just not good, you can kind of easily make it, but you really have to be interested. I know lots of people who aren't super talented but still do well- but people who don't give a hoot generally fail.

Your interest is not completely determined. It's not like you will never like science - if you keep an open mind you might get interested. So if you want a degree in STEM, get interested in stem. just look at pop sci shit and if you think you could see yourself doing this, then consider getting a degree. you could check out youtube channels like infinite series(math), numberphile (math), spacetime(physics), or computerphile(cs) and if any of these consistently interest you, it could be good to do a degree in these fields.

If you're not interested at all, just do what you like - you can generally still get an allright job with any university degree - if you do well.

Is learning by osmosis possible? Will I become smarter just by hanging in here?

Okay, I'm a total idiot, but I've been at this for half an hour and even with a solution I have no clue how you're supposed to do it.

How do they go from:
sin(x + 1) − sin(3x + 3) to -2sin(x + 1) cos 2(x + 1)
I thought sin3A was 3sinA - 4sin^3(A), so how do they get the cos2A?

>>9789392
> I thought sin3A was 3sinA - 4sin^3(A)
= sin(A)(3 - 4sin^2(A))
= sin(A)(3 - 4(1-cos^2(A)))
= sin(A)(3 - 4 + 4cos^2(A))
= sin(A)(4cos^2(A) - 1)
= 4sin(A)cos^2(A) - sin(A)
IOW, factoring and unit-circle identity.

>>9789452
Ah, it's supposed to be cos(2a), not cos^2(a), but I think I get the idea now, thanks.

Is getting a Chem minor as an applied math major a waste of time?
>inb4 do a CS double major or minor

>>9789383
I'm trying to do that to my mom so she won't feel like she missed us when she gets out of her coma.

I have just proven a magnificent theorem:
[eqn]\begin{bmatrix}
0 & 1 \\ 0 & 1
\end{bmatrix}\begin{bmatrix}
2 & 0 \\ 2 & 1
\end{bmatrix} = \\ \begin{bmatrix}
1 & 1 \\ 1 & 1
\end{bmatrix} \begin{bmatrix}
1 & 0 \\ 1 & 1
\end{bmatrix} [/eqn]

>>9790047

Can someone post the PHENOTYPE ed witten youtube poem thing link?. Want to show a friend.

>>9790080
Evermind, finely found it https://youtu.be/3nJBF_H56Oc

>>9790047
What's your theorem?

>>9780216
Gravitation powered device is perpetuum mobile as long as object it is attached to have mass. Prove me wrong.

What actually is the difference between continuity and uniform continuity? Apart from their different epsilon-delta definitions, what is the significance of uniform continuity?

>>9790255
uniform limit of continuous functions is continuous and there are similar theorems about derivatives and integrals. in other words, uniform convergence usually preserves structure in some sense, pointwise convergence doesn't preserve shit.

>>9790271
nevermind, different question

>>9790255
Continuity is a local property while uniform continuity is a global property. You should look up theorems that depend on uniform continuity but to make it quick, the actual important thing is that while continuity can help you establish local inequalities, uniform continuity can help you establish global inequalities. As in, inequalities that hold in the entire space. This is highly non-trivial and is the entire reason we care.

What course should I take If I'm interested in Evolutionary Biology?

>>9790572
>What course should I take If I'm interested in Evolutionary Biology?
evolutionary biology

>>9790572
>>>/pol/
>>>/x/

Is there a rigorous analytic definition for the centroid of a given region in space?

A while back somebody posted some papers on how forcing yourself to recall information is better for retention than just rereading it. Does anybody remember who did that or have a link?

When I tried looking I just kept getting self help books, but I know that one of the guys who worked on the study hosted the papers they wrote on the experiment for free somewhere.

>oscillate in two mutually perpendicular plane
What do they mean by this?

>>9780216
Did anyone here read the whole Principia of Newton, or partially?
What will I gain if I read it?
what do you think of the very geometric reasoning he uses in the book versus the now modern symbolic algebraic reasoning, which reasoning do you like more?
Pic related, it is his proof for Kepler's 2nd law

Please recommend me a book to learn Laplace Transform. I'm a brainlet btw.
Also what book would you recommend for learning differential Equations in general, I've been using Ross but the section on Laplace transform is confusing.

Why was I born now? Why? Why not in 300 years when we made Mars habitable and have convenient methods of travelling to Mars?

I wanted to be the first one to establish a nudist colony on Mars, but my dream will never be fulfilled.

>>9791074
>I wanted to be the first one to establish a nudist colony on Mars, but my dream will never be fulfilled.
Not with that attitude.

>>9790894
I've read parts of it and its really cool, but functionally unless today. It's a piece of science history and a fascinating on at that, but everything in there has been replaced my modern physics. But reading AND understanding it fully will probably make you an expert in classical mechanics tho.

Also I respect the geometrical model of proof. Its gorgeous but very very impractical

halfway through mechanic assignment and suddenly i can't access wolframalpha.com anymore
cmon man i can't solve all this fucking shit alone

what is [math]\text{Axiom of choice}[/math]?

>>9791239
>what is Axiom of choice?
a spook

Does anybody know of a book explaining the origin of homo sapiens, the geogrphic distribution of other homos and ho was evolution made from neanderthal/cromagnon to sapiens? You are allways talking about this but never seem to link sources. I dont want to think you are saying bullshit you read in some popsci, right? ORIGINALDESU

>>9787189
Do you know what each of the components in a 4-vector means? v0 > 0 means that the particle is traveling towards the future.

>>9791347
Its a direct quote from Shchutz book.

>>9791149
torrent mathematica

>>9791239
A meme that keeps set theorists from losing their job.

Is it possible for water to get attracted and go towards a bullet? Say you shoot a sniper bullet, or even a tank shell. Can the high number of rotations create enough static electricity to actually "lift" water from a surface, like a lake?

>>9791240
>>9791997
can you be more specific pls?

>>9792246
>>9791239
if a function has more than one inverse, you can pick one of those inverse functions to be the inverse of that function

>>9780405
Quite some:

mechanics, thermodynamics, electricity and magnetism, quantum mechanics, etc.

Relative to studying physics, it is a bit more simplified, but you still need a good understanding of basic physics in order to be a good chemist. If you want to do something like biochemistry, than physics is less important, but for things like physical chemistry, it is quite important. (Duh)

>>9781803
No, STEM majors require dedication. It's not something you can just do on a blue Monday.

>>9792114
I'm not an expert, but I think not. You would need a LOT of static electricity to cancel the downward force on the water even before it can be lifted.

I'm interesting in looking up statistics about human body proportions, but I have no idea where to start. I could only find basic height and weight from CDC, but I'm more interested in random small stuff, like facial stuff, digit ratios, etc, and how it all relates to each other.
Can some one point me in the right direction, or give me some search terms to get started on google scholar?

Stupid question here but how viable of plan is it to pick a job in industry (let's say finance) and study math (non-applied stuff) in your free time? Will you even have any free time if you go into industry?

would YOU approximate this to linear? (trendline)

what's a good resource to grok what p-values are. like a textbook or a lecture

>>9780218

what do you not understand? by systematic about your ignorance.

Not a question but both me and my enemy are quite retarded in this situation

>uni makes me take a placement math test
>have to get 76%+ to be able to take calc
>expected to remember shit from courses I took literally 3-5 years ago
>get a 60% and have to retake it after several hours in their stupid ass training module
I should have just copied and pasted every god damn question into google. I aced all the classes the content was from. I don't see why I have to remember all this prereq shit when they could just give me a little review booklet over the summer before I take calc and everything would be fine with none of my time wasted on this.

the electric field when r<a and r>c is 0, right? And the field when a<r<b is p(r^3 -a^3)/3er^2, and when b<r<c it's Q/4(pi)er^2, right?

>>9793161
>what do you not understand?
I don't understand what [math]C[/math] we need to choose such that [math]|\{t:|\sin(t)|^{-1/p}\geq \lambda\}|\leq C\lambda^{-1/p}[/math] for all [math]\lambda>0[/math]. As you can see, all my efforts have been fruitless.

>by systematic about your ignorance.
Please construct a proper English sentence, you brainlet.

>>9793375
Correction: I meant [math]|\{t:|\sin(t)|^{-1/p}\geq \lambda\}|\leq C\lambda^{-p}[/math].

>>9780216
Was prescribed an SSRI by my pysch, and picked up my first prescription this afternoon. I'm supposed to take it in the morning. Should I take it now, or should I wait until the morning to take it for the first time?

>>9793384
/sci/ is not a place for medical advice.

But still I suggest you take it in the morning, just so you don't directly fuck up the new cycle that your body needs to get used to (I have no idea how strong SSRI is, but in any case this advice works).

I need help understanding where a proof went wrong.

Suppose that [math] f(x) [/math] is a smooth function such that [math] \int_0^{\infty} f(x) dx = C [/math] (it exists and is a constant. By the definition of improper integral, this just means that if [math] F(x) = \int_0^x f(t)dt [/math] then [math] \lim_{x \to \infty} F(x) = C [/math].

Then [math] \lim_{x \to \infty} f(x) = \lim_{x \to \infty} \frac{d}{dx} F(x) = \frac{d}{dx} \lim_{x \to \infty} F(x) = \frac{d}{dx}(C) = 0[/math].

However, I was told this is wrong. At what step did I fuck it up? I assume that it is when I interchange the limit with the derivative but I thought you could do this with smooth functions (infinitely differentiable) so what's the problem?

>>9793464
>However, I was told this is wrong.
Why?

>>9793469
I don't know, see https://brilliant.org/problems/breathing-implies-alive/

There is one guy who claims there exists an infinitely differentiable function with finite integral in [math] (0, \infty ) [/math] but with non-zero limit. Note, he is not constructing it. He just says "We use it in functional analysis".

I tried googling it and found nothing relevant. I really just want to know why my argument is wrong.

Hey guys, I'm a senior (18, of course) and I've been having some serious health problems for the past year so I'm currently very behind in Chemistry and desperately need help with this question:

"Before you are two clear, colorless solutions of ionic compounds. one is a solution of sodium chloride, the other is of a nitrate compound with an unknown cation. Using a spot plate and pipette, combine the chemicals and observe the resultant reaction. If the resultant precipitate dissolves in hot water, what must the unknown cation be?"

I don't even necessarily want an answer, just anything that can help direct me in the right path will be appreciated.

Only asking here because I wouldn't be surprised if a lot of you wear glasses. I've had a weak prescription since high school and never wear glasses but my vision has some how gotten really bad in the past month. Is this normal? I basically have slightly drunk vision 24/7 now.

>>9793525
Look up precipitation reactions. This one is a very common one.

NaCl + ?NO3 -> NaNO3 + ?Cl

The ?NO3 is a clear colourless solution and the ?Cl is insoluble in water.

>>9793621
Would the unknown element be silver by any chance?

>>9792628
>Will you even have any free time if you go into industry?
I work a pretty intense full-time job. 50 hours a week usually. I also usually spend 10-20 hours a week playing video games. You'll have free time.

>>9785908
My favourite is the kilogram because it's the only base SI unit that comes with a prefix and the history behind that is interesting too.

During the French Revolution, getting rid of the old aristocratic measurements and replacing them with more "grass-roots" standards was hip. But when they wanted to replace the old stuffy measurement of mass, the grave, they decided it was actually well defined. So instead they made a new unit, the gram, and set it equal to 1/1000 of a grave, then made the base unit 1000 grams. In essence they continued to use the grave but under a different name and acted like it was a completely new unit of measurement they came up with on their own.

Do unis ever give refunds for shit units? The unit I've just had taught us nothing and was obviously just a front to get us to participate in the coordinator's shitty PhD experiment.

>>9781180
Just assign the discrete topology on R and you can prove almost anything you want about f being continuous
That'll impress your professor for sure

>>9793464
see https://math.stackexchange.com/questions/15240/when-can-you-switch-the-order-of-limits
I don't have the time to think through the specific conditions required for your switching of limits to work (remember that the derivative is defined as a limit itself, so you're working with two limits there), but it's pretty clear that just being smooth is insufficient and someone could construct a counterexample to your proof pretty simply.

>>9793464
anon think about it, if your limit wasn't to infinity but some arbitrary real number instead then what you have proved is that 0 is the only smooth function

as for a counterexample consider x*sin(x^3) or if you find it hard to convince yourself that integrates to a finite number consider the derivative of sin(x^3)/x

>>9792865
no

>>9793691
just get your piece of paper like a good goy

>>9793811
>if your limit wasn't to infinity but some arbitrary real number instead then what you have proved is that 0 is the only smooth function

Damn, shove a stick in my ass and call me a popsicle.

>x*sin(x^3)
Nice counter example. Thank you.

This is wrong, right?

>>9794738
It's a little hard for me to understand what you're trying to calcute and whether some are equations or just new defined variables.

What would happen if a 20-ish year old girl had her spine severed with a scalpel and alcohol by someone with a decent knowledge of surgery, around L2 verterbrae or so? What kind of spinal infection would she die from and how long would it take to kill her? Would there be any drugs that could save her life? Also, I assume her legs would be paralyzed but what about bowel/bladder function? Would she still be able to feel things sexually? This is for a TTRPG campaign I run, one of the players did some edgy shit so now I want to punish him by making her death as graphic and realistic as possible so he stops being a sadistic nutcase to imaginary NPCs.

>>9795194
What the fuck

Need basic maths help, making a raised bed for vegtables and need to figure out the volume in litres, I worked it out as 1639.4ltr but that seems too high

dimensions of bed 01
h 16in x w 3ft x L 3ft

bed 02
h 12in x w 3ft x L 10ft

what would the combined volume in litres be? did I get it right?

>>9795207
>foot & inch
You're doomed, brother. This ain't gonna work out as long as Americancer tries to force retarded metrics down children's troats hoping to keep it alive.

Is undergrad research valuable when applying for a job? Or is it only useful if you want to get into grad school?

Asking from a EE undergrad perspective.

I am looking for algebraic solutions for the problem of maximizing [math] 2(a+b+c) - abc [/math] given that [math] a^2 + b^2 + c^2 = 9 [/math].

I have already solved the problem (if you want to know the solution just ask me, I won't put it here in case someone wants to go in blind) but I used Lagrange Multipliers because no direct algebraic route worked for me. I am looking for a purely algebraic solution to know what I missed when attempting the problem without calculus.

>>9795380
Literally, anything you do besides jerking off in class is valuable when applying for a job. Doing research is obviously good, especially if you manage to participate in a conference because of it as then you can put a second bullet point in your curriculum. But being real, if what you want is just getting a job then an internship will be the best option.

And don't quote me on this, but if you already have an internship in your curriculum then maybe then the research is more valuable as it will make your record have more variety.

>>9795398
At least two internships are required for graduating in my country, so yeah that'll be covered. Research would just be a plus (and also helpful if I end up wanting to go to grad school).

>>9793627
Yup, that would be my guess.

>>9795387
I am just guessing, but maybe you could try spherical coordinates and find its maximum by equating derivates to zero, or probably. Another thought is that the AM–GM inequality trick might work somehow.

>>9795607
>try spherical coordinates and find its maximum by equating derivates to zero
This is a calculus proof, which I already have.

>Another thought is that the AM–GM inequality trick might work somehow

Well this is the kind of proof I am looking for but obviously I already tried AM-GM, Cauchy-Schwarz and even Power mean inequality. There seems to be no easy way of linking [math] a + b + c [/math] and [math] abc [/math] with the given condition. And it is also worth mentioning that AM-GM would not completely solve the problem because the variables are allowed to be negative. (In fact, the maximum occurs at a point where one of the variables equals -1).

I'm starting uni in August at a mid tier state school. My major is biological sciences. What can I expect my weekly workload to be like? I plan on working full time because I need to support myself and save up for my wedding next year. Is it possible to work full time while studying a science full time?

>>9795611
This is second-hand information but most biology professors hate their life and take it out on their students. Get ready for that. Also, if you are getting married I really hope you are like 30

>>9795619
I've heard something like that before. My first year at community college (lol) was very hit or miss. First semester biology prof was a really loathsome prick while the second semester prof was an extremely cheery lady. I'm expecting more of the former.

And I'm 25 now. I'm marrying my high school sweetheart.

>>9795611
Depends on the prof and course I suppose, but for myself I found most classes had very few assignments, except for courses with a lab component. You might feel like you have a lot of free time but make sure you're studying and reading texts. It's very easy to find yourself trying to memorize the 20 amino acids and the steps in the electron transport chain the night before a midterm.

That's another thing, early on things are heavy on the memorization part of things. Later on I did an honour's thesis and that took all of my time.

>>9795115
center or mass(centroid)

>>9795202
I wish there was a way to make the question more palatable but there really isn't.

>>9795194
looks like bowel/bladder function would be unaffected, just motor function in her legs judging from this chart
https://en.wikipedia.org/wiki/Spinal_cord#Function

>>9796002
Oh so she'd still be able to control herself? That's.... really nice actually. Like, that really makes her less of a burden. Because it's a post-apocalyptic world they are in so a girl who just needs to be pushed around in a wheelchair is less likely to get put down than a girl who needs to also have her shit and piss cleaned up after. I was pretty sure this girl was gonna be left to die pretty quickly. Of course she is still dying from spinal infection so she is still probabyl fucked.

Hey, in statics, why don't we consider force due to atmospheric pressure? If a 1m side cube is laying on a surface, what balances the atmospheric pressure?

Can anyone point me to some good free resources for bio-electric engineering?

>>9796198
It is not significant enough in the general case

>>9795387
Can no one solve this without using calculus? I'm asking because some fucker posted this problem in the algebra section, not in the calculus section. But there is currently no algebraic solution there.

>>9796227
Might one of these help?

>>9796471
ops
https://www.lifehack.org/articles/money/25-killer-sites-for-free-online-education.html

I have an exam coming up on Dynamical System, Jordan cannonical and phase portraits, can someone link me some good resources i.e. books or videos since the professor is shit?

>>9780216

Is there something I'm not seeing or is this unsolvable? I really feel like a brainlet

>>9796512
So what the issue, you have half of the circle?

>>9796512
>>9796555

any medfag or pharmacist here?
ive been on 3mg lorazepam for like 3-4 months now but i want to go out tonight and drink. i know that both benzos and alcohol act as a depressant. can i replace my daily benzo intake with alcohol? i dont want to get a seizure or something from withdrawal

>>9796555
Forgot to clarify sorry.
We don't know whether this part of the circle is half of it or not.

All known parameters are the measurements of the rectangle (6 base, 2 height) and that part of this circle touches the top of the rectangle and touches the bottom left and right corners.

>>9796566
Are these sides of the rectangle are proper tangent lines to the circle?
If that is not known then I dunno man

>>9796575
The top one is.
Wouldn't the other pair of lines being tangent to the circle defeat the entire purpose of the exercise? Since they'd only be tangent in the middle and thus would imply that r=2.

>>9796512
[eqn] {\color{Red} b}^2+{\color{Blue} c}^2 = r^2 \\\
{\color{Green} a}+{\color{Blue} c}=r [/eqn]

>>9796579
If the top one tangent then the side ones tangent too therefore bissetrix of the angels will meet in the center of the circle

>>9796484
nothing?

>>9796580
how do I fix TeX

>>9796631
Oh nvm it is Ublock Origin that fuck this up.

>>9796512
R=x+2
(x+2)^2=x^2+3^2
Solve for x

>>9795387
Guessing... the gradient of the first term in normal to the sphere. So you’ll need the gradient of the second term to be as well. So probably a=b=c.
If you want an algebraic solution, try changing coordinates so one points in the direction (1,1,1)

>>9796426
For area of 1m^2 F should be ~ 10^5 N, right? What's the reason it's not significant?

If I squish the end of a pipe, the velocity of water coming out seems to be increasing. But why is the massrate decreasing?

i'm on a site similar to ebay and trying to buy stamps for postage
there's me and a couple of other "bargain hunters" who try to bid near a threshold where we have a reasonable chance of winning the auction while not paying too much
then there's the "whales" who go like "fuck off i need these stamps, i don't want to play your stupid game of saving a few bucks here and there, i'll pay whatever"
over the course of a month the prices have gone up like 10%+ and i've had to raise my threshold
i'm starting to think that maybe it's better if i stop bidding for a while so others can get their demands fulfilled a bit so prices can go back down
it would probably be better if buyers could collude with each other so buyer A bids on one auction and buyer B bids on another auction so both get the stamps cheaper but that's not gonna happen
but what if i deliberately stop bidding for a while, could the price go down?
is there anything in game theory like this?

>have a bottle of water
>take one sip and close it back
>next day the water smells like shit
Is that normal? I know my mouth has bacteria in it but can it happen THAT fast ? It smells really bad

>>9796680
>a=b=c.
No, this is not the case. In the solution, only two variables are equal.

>>9780216
What's a formula for elementary work when both pressure and volume change?

Is it dA = pdV + Vdp?

>>9797084
3, 0, 0

>>9797084
a = (4.5)^0.5, b = (4.5)^0.5, c= 0 or any variation thereof

>>9797070
I don't think so, I refilled my water bottle the last few days without ever fully emptying it and it tasted completely normal

are gas giants literally made of gas? if you were to fall in there you would just float?

Is it really accurate to say that Planck meters and Planck seconds are like the pixels and frames of the universe?

What is the opposite of a theist, i.e. someone who believes there definetly is no god? Google only offers atheist as answer, but they don't belief there is no god, they just reject the faith in one.

>>9797139
I googled "do gas giants have mass", the second result was this, alas it was on reddit, I hope you can live with yourself.

>>9797134
>a = (4.5)^0.5, b = (4.5)^0.5, c= 0 or any variation thereof
This is not the solution. It is a=2, b=2, c=-1 which gives the maximum.

Also, I am asking for an algebraic proof, not the answer. I already know the answer, I am looking for a solution that does not use calculus.

>>9797146
>Non-belief is the denial of any religious or supernatural beliefs,
This is how the wiki page that might answer you begins, but I can't find the english version, there is in italian, spanish and french.

I looked for it, by looking at Foscolo a great writer and poet, but he seems to be defined as Atheist, rationalist but NOT without religion.
https://it.wikipedia.org/wiki/Noncredenza

>>9797070

Your morning breath can also smell bad after not having brushed the prior evening. Bacteria that would normally inhabit a healthy person's mouth cause this smell. I've worked in a microbiology lab and some streptococci on feeding trays produce the exact same "bottle mouth" smell.

>>9797146
Strong atheist.

I'm writing a sort of mod2 for lists, pic related. It e.g. maps

[1,2,3,4,5,3,5,6,7,7,7,8,9,11,11,12,12,12,13,13,13,14]
to
[1,2,4,6,7,8,9,12,13,14]

I wrote a straight forward Python implementation.
For efficiency sake, I'd be interested in one that doesn't create or returns another list. However, running through a list once and deleting its elements based on neighbor relations turns out to be quite tricky. Any takers?

ad, here's my code from pic related

https://pastebin.com/jDBDFbPW

Autism is on the rise. Shouldn't this be generally explained by more women being fatter and older nowadays when they have kids?

>>9797534
If you want to do it in place you can do this

L,i = sorted(L),0
while i+1 < len(L):
if L[i] == L[i+1]:
del L[i]
del L[i]
else: i+= 1

>>9797621
how does one cure autism?

>>9797621
or there are both more people in general and people are starting to diagnose autism instead of just thinking someone is "just like that"

>>9780216
retard here, can someone help answer this simple question

"A uranium undergoes radioactive decay and emits an alpha particle. What is the mass of the resultant atom?"

>>9797895
uranium mass - alpha particle mass = new mass?

>>9797905
ok so uranium mass=238.02891 and from what I've found the alpha particle mass=4, so 234.02891 or ~234? I'm really tired right now and I feel like I'm using the incorrect masses.

If radioactive decay is spontaneous how can we possibly determine half lives and rates of decay?

Like if some uranium has a certain half life, wouldn't it have to decay at a constant rate to meet that half life?

>>9797930
Never mind I'm an idiot. It decays at a regular rate but you don't know which individual atom will decay next. Right?

What's the motivation behind believing in a flat earth? I.e., for Creationism you reject science because it means Genesis isn't factual... so what's the deal with flat earth?

>>9798013
brainlets want to feel like they're smarter than everyone else by unraveling some grand conspiracy so they look for ridiculous "evidence" like pic rel to convince themselves while lacking any self-awareness because brainlet

How do I show
[math] \delta (x) = \lim_{\epsilon \rightarrow 0^+} \frac{1}{2} \epsilon |x|^{\epsilon - 1} [/math]
(equation (35) on http://mathworld.wolfram.com/DeltaFunction.html)?
I tried Fourier Transform and [math]\int \delta (x) f(x) dx = f(0) [/math] but I couldn't do it with either...

>>9797621
It's on the rise because it's the next step of evolution
Sorry, neurotypicals

>>9797534
...def mod2_for_lists2(ps):
... ps.sort()
... idx = 0
... while idx + 1 < len(ps):
... if ps[idx] == ps[idx + 1]:
... del ps[idx]
... del ps[idx]
... else:
... idx += 1
... return ps

>>9797626
>>9798390
Cool, I didn't know the trick of using while instead of for, for these situations.

If the list isn't sorted, I suppose one needs a "double loop", which really is then a double while. Do you see any issues with the following unsorted extension?

i = 0
while i + 1 < len(ps):
j = i + 1
while j < len(ps):
if ps[i]==ps[j]:
del ps[j]
del ps[i]
else:
j += 1
i += 1

>>9797621
the most common and significant explanation seems to be that it's just being diagnosed more often. there's a lot of leeway for what is considered normal. lots of "normal" people are pretty dumb or behave a bit weirdly. and now that there's more awareness about autism more people are getting diagnosed even though they are still relatively normal. and for example even today an adult might not qualify for a diagnosis of the 'tism but they could have gotten diagnosed when they had more issues during their childhood.

PS I wonder about this because I just figured out .sort() and sorted(...) don't sort a list of sets

>print(sorted([{1,2,3},{5},{1,3,4},{5}]))
doesn't have the singletons with 5's after another

How do you solve this basic physics problem without Calculus?

Suppose you throw a ball from a height [math]h [/math] with an intial speed [math] v_0 [/math]. For which throw angle [math] \theta [/math] is the throw distance [math]R [/math] maximal?

I only got as far that
[eqn]R = \frac{v_0^2}{2g} \sin(2 \theta) \left( 1 + \sqrt{1 + \frac{2 g h}{v_0^2 \sin^2( \theta)}} \right) [/eqn]
But how do you maximise it?

>>9798429
Yes, the fact that it runs in O(n^2), while sorting it and going through it with a single loop runs in O(n log n)

>>9798436
Sets have no order, you cannot sort them. Instead convert them to a list or some other ordered collection

>>9798429
>>9798724
Also, the last line is hopefully outside of the "else" branch

Brainlet question here (babby's first point-set topology book):

The definition of open sets depends on which topology we use when defining a topological space. So the definition of continuity using open sets naturally depends on what topology we use to define open sets. Does the epsilon-delta definition of continuity we learned for real numbers also hold true for any topology defined on the reals, or just the standard topology?

>>9798667
there is no good explanation without using some form of calculus
without calculus the teacher would just tell you that it's 45 degrees

>>9798667
Time in the air: t = 2*Vy/g
Throw distance: s = Vx*t = (2/g)*Vx*Vy

Distance is maximised when Vx*Vy is maximised subject to Vx^2+Vy^2=v^2.

Put a=Vx^2, b=Vy^2, c=v^2.
a+b=c => b=c-a => a*b = a*(c-a) = a*c-a^2 = (c/2-a)^2 = c^2/4-(a-c/2)^2. Clearly this has a maximum when a=c/2 => b=c/2, i.e. Vx^2=Vy^2=v^2/2 => Vx=Vy=v/sqrt(2), i.e. when the angle is 45 degrees.

Basically, the largest rectangle you can fit inside a quarter-circle is a square, so Vx*Vy is maximised when Vx=Vy.

>>9795387
I spent way too much time with this...
Using spherical coordinates with one axis pointing in the direction (1,1,1) I reduced it to

maximize (sqrt(2)*cos(q)^3 - 5*sin(q)^3 + 7*sin(q))*9/2/sqrt(3)

and Wolfram alpha gives the answer 10, which is correct. So I'm pleased it reduced to one unconstrained variable, but disappointed that I don't see how to maximize it without calculus.

I've been out of school for a while now and wanted to check my math skills so I can go back to studying, so I was trying to use khan academy to do so but I am honestly confused, is 20/7 = 2.(6/7) in america? is math different there? is there something I am not seeing or understanding (I assume its this option)?

idk how to do this, when i try using the quotient rule it takes way too much algebra
[math]\frac{d}{dx} \frac{\sqrt{x}}{x^2-2x}[/math]

>>9798836
Anybody?
Somebody help me with this please?

>>9800138
20/7 = 2 6/7 = 2 + 6/7 but different to 2 (6/7) = 12/7

>>9800410
First simplify by factoring the denominator and dividing the square root from above

>>9800493
i did that, and ended up with a completely different answer than what's in the book, which is:
[math]\frac{2x-3x^2}{2\sqrt{x}(x^2-2x)^2}[/math]
it also says to specifically use the quotient rule

>>9800567