/SQT/ - Stupid Question Thread

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Is a Nuclear Physics PhD a waste of time?

>>7700915
what is your long term project? The answer is irrelevant if we don't know what you want to do with it.

>>7700915
why the fuck are you asking us? If you are at a point in your life where a nuclear physics PhD is a viable idea than you would know much better than we would.

honestly PhDs in specific fields which prepare you for research in those fields are quite obviously worth it if thats what you wanna do

I'm in 3rd semester of CS and passed everything except the programming stuff (Java, C), analysis was hard but I loved discrete structures and linear algebra

let's say I will somehow pass the programming stuff and I'll be able to finish my CS bachelor without really knowing how to program because I suck at it, but knowing all the other stuff like math, theoretical shit and computer engineering stuff

is there any chance for me to get a job somewhere where I don't have to program (a lot)? it's not like I care, I will sudoku anyways in a few months/years, I'm just curious

>>7700922
I'd like to either work on Fusion or Cyclotrons, wouldn't mind working in medical, energy, defense or academia.
I'm an experimentalist btw

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>>7700924
>I'm in 3rd semester of CS

I'm so sorry

>>7700901
Why can't we just test the inner workings of early post-receptoral cells in the human visual system in-situ? We've done it for photoreceptor cells. why not go further?

>>7700923
Job prospects really brah, I'm coming up to my third year and need to start making decisions. It's a choice between Solid State, Nuclear or Plasma for me

>>7700924
This is >>7700928, I have a PhD in CS and I barely do any programming these days and when I have to, it's mostly high level stuff like Matlab. Computer graphics is generally the way to go.

>>7700929
Go nuke faget

How do I prove that (F [A])*=F*[A*] where A is an operator (and therefore F [A] a generic function of the operator)?

* is the usual complex conjugation

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>In most cases, including even simple curves, there are no closed-form solutions of arc length and numerical integration is necessary.
If I have third-degree polynomials on the form ax^3 + bx^2 + cx + d, can't I just get the arc length using pic related? Or will it not be a closed-form solution somehow?

The main reason I'm not using linux is because windows 7 is more simple and easier to use and I'm a dumb idiot, is there any bistro that offers the same user friendliness?

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>>7700932
cheers brah

>>7700942
Not really, Ubuntu is as easy as Windows is these days, the problem is you're used to Windows and don't want to learn Linux. If you had to start anew right now, both would be equally easy for you to learn.

Is it possible to go from a moderate understanding of Algebra to early first-year college level Calculus in 4 months?

>>7700952
It is.

if every element is either diamagnetic or magnetic, doesnt it mean that magnetism is the only force and other phenomena like temperature, friction, radiation, oxidation, static charge and discharge etc. are just its different interactions, which all are dependet only on the magnetic properties of the interacting matter?

tldr cant everything be considered a magnet?

>>7700915
Only if you intend on a career working in nuclear physics.

You can still get the usual jobs in the finance sector.

>>7700947
In Windows you don't need the command line for everything.

If gravity is the curving of spacetime. Then gravity is a state of spacetime.
Then the flat earthers are right in saying gravity doesn't exist. They site the graviton :)
Is the effect of curving spacetime what we call gravity?
They're right but in the wrong way. Idioso

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>>7700959
fucking magnets, how do they work

>>7700926
>I'd like to either work on Fusion or Cyclotrons, wouldn't mind working in medical, energy, defense or academia.
Do you have a nuclear or other engineering background? Sad to say, but you will really struggle to find a job without a professional license, but even then and even if you're coming from a top school gunning for research positions is a stupid idea because you won't get it unless your adviser knows someone and someone happens to be retiring.

All the cool fields are like that unfortunately. You have to be a goddamn genius to get to work on what you want.

>>7700966
In Ubuntu you have guis for pretty much everything. I don't remember the last time I had to use the command line.

>>7700966
Dude Ubuntu is even simpler and more basic bitch than Windows.

I don't understand why you think you would ever need a command line just because it's Linux.

Android OS is linux too you know? You can't tell me that is less intuitive than windows.

>>7700974
I know bro, I'd do it for the love of it (always been fascinated by it)

I'm 20 and the only experience I have with university is fucking up my GPA to a 2.6 after about a year because I was irresponsible. If I go back and really buckle down, is it possible that I could go for a graduate degree and work in research or academia? I'd like to either work in Biology, Mechanical Engineering, Astronomy, or Computer Science.

>>7700947
the other reason I'm not going to go linux is because videogames

>>7701020
Then why the fuck do you ask for a user friendly distro if you don't want one?

>>7701020
You can run literally anything you can on windows with 99.9% the performances, this isn't the fucking 2000s, ask around on /g/.

>>7701018
Ask yourself why you failed. A major part of being an academic in the first place is being a well rounded, self-sustaining individual. Whatever caused you to fail before -whether it's time management or excessive drinking or whatever- will or something similar will probably cause you to fail again if you're wired that way. See if you can make major lifestyle changes first, buy some senior level textbooks in subjects you are interested in and see if you can be dedicated enough to study them properly and QUICKLY.

Do this wasting money and time on a blind hope that you will do better this time around. You might be able to fix your GPA (2.6 is below the minimum required for most grad-schools though), it's definitely not impossible, but you will need to perform better than most students so be sure you are actually capable of doing that.

>>7701022
>>7701023
why the hostility?

>ask /g/
>realize I'm on /sci/
ahahaha sorry, I though I was on the /stg/ of /g/

>>7701049
>People swearing near me means they're being hostile ;_;

Grow a pair.

Does anyone know at what level the AP Calc-BC Test is?

Why doesn't the tidal force contradict the 2nd law of thermodynamics? Where is it getting the energy from?

Not really /sci/ related.

Freshman here. I'm going to be about 33 credits in after spring and I want to transfer by fall. Will it be possible for me to get everything together over summer and transfer by fall or am I going to have to wait until spring 2017?

Is it possible to become an engineer with just a high school diploma?

>>7701174
tidal force is due to gravity, which decreases with distance. As an object orbits, the tides it creates drag it back due to friction and actually slow it down. Slower orbital velocity means a larger orbit due to Kepler's Laws, which in turn decreases the tidal force because it's farther away. I don't know if this answers your question but yeah.

When we differentiate a function, what exactly are we doing? What are we accomplishing?

>>7701246
Finding the rate of change of a function in the limit of x-->0

>>7701246
finding the function that describes the instantaneous slope of the original function. In mathematical terms, [math] \lim_{ h \to\ 0} \frac{ f(x+h)-f(x) }{h} [/math]

Why is 0! = 1?

>>7701246
You're approximating it by a linear function near that point, because linear functions are easier.

>>7701246
youre imagining really small triangles at every point of your function and finding the equation that will tell you the ratio of rise to run (tangent, opposite over adjacent) at those points

>>7700936
Not with the usual tricks (at least I don't see it)
You can make it work with second degree though (do an affine transformation then a sinh substitution)

>>7701350
It's just a definition. It tends to simplify combinatoric proofs so they defined it that way.

How do I pick up studying as a faggot with ADHD & no meds?

>>7700901
Lets take some simple calculation, like: what's the speed of ball thrown 20 degrees above central line with speed of 20m/s, when it reaches ground that's 2m below the throwing place? In high school physics air resistance is left away, because it's too difficult to calculate.
Is there, however, a "simple" way to calculate it? If we know the size of the ball and it's speed

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>>7701722
Hmm ok. I was hoping you could integrate it as a composite function with the outer function being sqrt(x) but it seems you can't do it since the f'(x)^2 doesn't differentiate to a constant.
>You can integrate them by substituting u = g(x) when
>You know how to integrate the outer function f.
>The inner function g(x) differentiates to a constant — that is, it’s of the form ax or ax + b.

So adding up a bunch of line segments is the best/only option? Is there a method for improving the accuracy, like compensating for the length that you're missing since it's a smooth curve rather than straight line segments? Like in pic related, the sum of the lengths of the red lines will be shorter than the arc length of the black curve. How do I account for that discrepancy?

>>7701751
https://en.wikipedia.org/wiki/Drag_coefficient

>>7701751
google euler lagrange equations

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Thought someone might like this. Its the latest Pluto photo from New Horizons.

>>7701800
Forgot to attribute:- of course from the NASA site

>>7701800
why does everything on pluto resemble a heart? It's like it's trying to make us feel like shit for taking away its status as a planet

>>7701800
>jpg
>Proving the first up close images of the most distant planet in a lossy format
This is absolutely fucking disgusting. It's like they think "the public" will just gladly eat up whatever slop they throw out. I have standards.

>>7700963
>You can still get the usual jobs in the finance sector.

why do you keep spreading this blatant bs

>get a phd in physics, you can work at merrill lynch and make millions

fucking clueless imbeciles

>>7701823
>why do you keep spreading this blatant bs
Because it's what the data shows.
https://www.maths.cam.ac.uk/sites/www.maths.cam.ac.uk/files/pre2014/undergrad/course/transferable_skills.pdf

Why are you posting here when you obviously have no idea what you're taking about?

Could someone clarify the definition of the [math]\mathcal{L}^{\infty}[/math] space of sequences for me? Is the norm [math]\max_{i}\lvert{x_i}\rvert[/math] or [math]\sup_{i}\lvert{x_i}\rvert[/math]? The definitions I've found use the former, but I want to make sure

>>7701839
The latex worked in preview at least. What I'm asking is do you require the max to exist or the supremum to be finite?

>>7701246

You're finding the rate at which a function increases or decreases at a specific point

>>7701762
No, I don't believe there is an analytic way of computing this. It is actually quite famous for not being computable: check out elliptic integrals, this was actually a very active area of research in the nineteenth century.
Now I have never taken numerical analysis so I don't really know how you would compute this in practice. A slightly less naïve approach, I think, might be to graph the function x -> sqrt(1+|f'(x)|^2) and then use standard approximation techniques.
I remember having heard about Simpson's method: the idea is to slice up the interval in smaller intervals and approximate the function on each of these intervals by a degree 2 polynomial. I think the error term was quite small in spite of the approximate integral being quite easy to compute.

If trying to harvest hydrogen, is the hydrogen mixing with the oxygen what sets off the explosion? Or does it need something like a fire?

If I were to put my finger on the right end of a block that sits on a frictionless plane and push, would it go straight forward, spin only, or spin but also move forward?

Which courses should I take before taking real anal?

>>7700933
spectral theorem

>>7701951
None, it's usually a first semester class in Europe and Asia.

>>7701839
>>7701841
It should be the sup. Since the sequence is infinite, it may not have a max.

>>7701951
You should have finished highschool. That's all.

>>7701949
Move forward only there's no friction ergo no pivot point for it to spin

>>7701949
Depends on the angle that you're pushing it at.
If you push it perfectly perpendicular to its center of mass, it'll move straight forward, no spin.
If you push perpendicular away from the center of mass, it'll move forward but will spin too.
If you push it at a 45 degree angle on a corner, it'll spin and not move.

>>7701959
that makes sense, thanks

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Solve
20 / 5 (2 * 2)

Is it 1 or 16?
Show your working.

>>7700901
How does ethanol affect the brain? I'm drunk right now and I'm wondering how the ethanol is affecting my brain chemistry. Any biochemists that can explain this?

>>7701956
>>7701960
Really? Then which books besides rudin?

>>7701967
Parentheses-->Exponents-->Multiplication/Division-->Addition/Subtraction

>>7701980
What do you have against Rudin?

>>7701967
>>7701981
The question is obviously lef-to-right or right-to-left associativity with the multiply and divide. DESU, who cares. If you write an equation like that then you deserve whatever you get.

>>7701982
Nothing, but I would like to have more options. I preferred lang over spivack, but I don't have a grudge against spivack.

>>7700952
Yes. Try using Khan academy. It'll likely help you out.

>>7701985
When would left or right assoc. be ascertained? Is left not the regular way of doing things?

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>>7700901
Im doing babby first machine learning program. I want to be able to use apache access logs to determine whether or not to give a customer a coupon. EX. some customers may pay many visits to the "pricing" page, they would probably be good candidates to receive the coupon. Other customers might have already gone to checkout but cancelled, they would also be good candidates.

If I have: ip address, pages visited, coupon issued(y/n), and purchase made (y/n) as my training set, I assume I can teach the model to predict whether or not to give a customer a coupon.

My question is: how do I go about this? where can I find a tutorial on this sort of thing?

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How to do this step-by-step and only using change of variables?

>>7702297
u=a^4+t^4
du=4t^3dt (a is a constant)
dt=1/(4t^3)du
now substitute in and integrate

is there any way for a normal person not majoring in anything STEM to learn how to understand higher level math?

How difficult would it to learn university level calculus with next to no experience with it before.

>>7702448
Sure, any idiot can learn basic category theory for instance if you really wanted to from a textbook or youtube videos

You'd have no motivation and be like "why the fuck am I doing this" though

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Final in 34 hours, fml

>>7702458
What are you wanting to use it for? Or rather, why do you need to learn it? To answer your question, it depends on how fluent you are with algebra

>>7702459
any recommended youtube channels? i like math because it makes my brain feel good

Why are right cosets defined this way?

Here is how my book defines the equivalence relation ~ to generate right cosets Hg

Let H be a subgroup of G and define ~ on G as
a~b <--> ab^-1∈H, a,b∈G
Where, for g∈G, the equivalence classes of ~, called right cosets, are
Hg= {x∈G: xg^-1 = h∈H} = {x∈G: x=hg, h∈H}

Why not define ~ as
a~b <--> ab∈H, a,b∈G
Mustn't it be true that, if ab^-1∈H then ab∈H (since H is a group)? Then why define them this way?

>>7702485
Nope, ab^-1 might be in H but that doesnt mean that ab is in H at all, if b^2 is not in H.

Think of H as R^2 in R^3 for instance. The cosets of R^2 are horizontal planes x+R^2. The condition that vectors a and b are in the same horizontal plane is that a-b is in R^2. It will NOT be the case that a+b is in R^2 however (usually).


The element ab^-1 is kindof the "group theoretical difference" between a and b. Its what you have to multiply b by to get to a.

>>7702499
I cannot express my gratitude enough, thank you!

>>7702466
Major is economics and finance. And that comes with calculus. I've had algebra and I'm somewhat comfortable with it. Just wondering what the difficulty level of calculus would normally be at a university.

>>7702532
Probably some of the most useful math you'll take in college, especially for econ.
Don't take it lightly, study hard and learn everything.

That being said, I don't thinks it's terribly difficult. It's going to require you use everything you did in algebra and trig, but if you review it you should be fine.

>>7702561
Thanks you. Reassuring to hear, think i'll visit /sci/ more often.

>>7702532
This anon>>7702561 pretty well nails it but I'd like to add, as a quick litmus test to ensure you have the requisite material, go here http://tutorial.math.lamar.edu/cheat_table.aspx
And check out the algebra and trig cheat sheets (full versions) and make sure everything makes sense and that you know how to use all if this stuff.

>>7702480
https://www.youtube.com/watch?v=rjLJIVoQxz4&list=PLkyBCj4JhHt9G55u1vgx_DF0C7DXVsBS8

has physics too

im going crazy since yesterday about the following question: How do i find a new speed from two objects that are spinning on top of a merry-go-round? If both objects are on a merry-go-round (on the edge) at a certain speed in meters per second, and one object decides to move to the center of the merry-go-round whilst still spinning. What would be the new speed, with a given radius of the merry-go-round of course. I know I have to use the angular momentum and the momentum formulas. Is there any other formulas that i should considered? i made a thread about it. Am i going for hell for that?

I'd like to learn how to code but don't have much experience with it or computers in general. I have had a decent amount of math though (math and stats minors in college). Anyone care to recommend a first language? Also, when do I get to start using all of the cool math I've learned? I remember I tried learning to code a couple years ago but got bored as all I was using was arithmetic and basic algebra

>>7702590
>http://tutorial.math.lamar.edu/cheat_table.aspx
Much obliged.

>>7701815
You know they have the original files in a format that normal desktop computers aren't even set up to read, right? Of course NASA thought of lossless formats. I'm not sure if your post is bait or not.

>>7702661
What are you even talking about? There's no reason they had to use jpeg.

tif, png, webp lossless. Whatever. But instead we get some garbage jpeg probably using a relatively shitty quantization table as well. I'm pissed, but not pissed enough to bother checking.

>>7702666
I think you should just appreciate the fact that we have true photos showing Pluto in detail in the first place, Satan. The image is grainy anyways, but don't worry, the uncompressed image is out there.

>>7701102
Differentiation and integration techniques and applications incl curve length, and you should be comfortable doing calculus on polar coordinates and with parametrized curves I'm the plane. Taylor series and some trivial, mostly comceptual "real-world" approximations of discrete phenomena. Just download past year FRQs and you should get a good idea.

Don't learn to the test if working independently, it's too easy and rudimentary to tell you that you've got everything you need down.

>>7701350
if you have an empty set there is still one way to arrange it. well you can't really arrange 'nothing' depending on how you look at it but that's how the reasoning goes

>>7700936
You can easily choose f such that the integrand lacks an elementary antiderivative

Heres one.
Is a transistor not just an and gate?

>>7702917
https://www.youtube.com/watch?v=SW2Bwc17_wA

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>>7700901
Why haven't we invented a decent way to increase penis size yet?

>>7702925
so yes?

>>7702935
>Why haven't we invented
What do you mean by "we", Peasant?

>>7702935
>>7702958
Well, with gene editing, all men should soon be able to have the size of penis they really want.
Me, I would have 2 of them, the second one would be where my belly button is. 2 cocks and 2 women, double the pleasure all round.

My secret santa is a huge physics nerd and student (probably posts here too).
What's the best book for me to get for him? He's 26 so he's pretty sure about this shit.
Or if you guys have a meme book about physics that works too.

>>7702906
However this isn't to say that the length isn't well-defined. Curve length is precisely formulated in general metric spaces: https://en.m.wikipedia.org/wiki/Rectifiable_curve#Definition

What kind of interpolation technique should I use when trying to predict the travel time depending on the time of the day?

>>7700972
>are you a magnet

well im indeed either attracted or repelled by most things I interact with.

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If I make an alloy out of Iron, Nickel or Cobalt, and another non-magnetic metal will the resulting alloy be magnetic depending on how the ratio of the mixture?

>>7703111
Please help me, my aim to make a magnetic alloy with a low melting point

what's a good Mac to get to learn security? should I go with an iMac or laptop?
also, how far back to go in learning different os for security?
as far as Windows xp? newer?

Why is seeing "Anonslastname et al." in an article so goddamn satisfying? Am I a narcissist?

>>7703116
Only if you use Cobalt 60.

>>7702958
>we, anyone from our species, human beings
Alternative form for that question
>why doesn't the human species holds the knowledge of how to increase penile length and thickness without dangerous surgical procedures
Happy now? Oh all mighty /sci/autist.

>>7703519
Trying to get me killed. You prick

>>7703111
>>7703116
Need answers. Answers that won't kill me. Please

biochem here but have a course in physics.
i have some assignments for tomorrow and i'm just SHITE at physics and behind a bit.
Like 3 exercises I want to really understand.
Does anyone know any good materials on that? it's about laws of conservation of mechanical energy and some dynamics.

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How can I convert my 1dm3 of 20vol. hydrogen peroxide into 40vol. ?

I only have 100vol. hydrogen peroxide available for use. I want to know the volume I need to add to make it 40vol.

Thank you

>>7703869
so if you have 100vol h2o2 just take 400 ml of it and put that in 600ml of water.
whats the big problem?

>>7703877
I don't think that's how it works mate

>>7703896
Nigger yeah it does?
You have a 100vol of something that means you literally have just that.

Take 400ml of that and add to 600ml of water.
The total solution is now 1 liter.
400ml of that 1 liter is h2o2.
400/1000ml * 100% = 40%
it;s not rocket science you nigger

>>7703907
40vol. h2o2 is not 40% you fucking idiot

100vol. h2o2 is only 30% it's not pure hydrogen peroxide

Kill yourself underage retard

>>7703910
VOL means % jesus christ you stupid fag.
What the fuck does vol mean then?

>>7703911
vol means volume strength ie amount of oxygen produced by 1cm3 of hydrogen peroxide

>>7703087
magic everywhere in this bitch

>>7703111
Need answers to this pretty please!

>>7700959
Just because every element has a magnetic field doesn't mean it's the only property that matters.

Is it possible to travel at the speed of density waves?

Having a brain fart right now

A matrix with full rank means it is linearly independent and therefore does not span

Am I right??

That's irrelevant to my question ^

>>7704460
Full rank means it has linearly independent columns, not sure what you mean by span.
The image of a full rank matrix will span the whole space if that's what you mean.

>>7704475
Well I have a set
B={ 1+x , x+x^2 , 1-x^3 }
In P^3 I'm assuming right? but anyways I'm expressing as linear combination
I have p(x)=5 , p(x)= 1+2x^2 -3x^3 , p(x)= 5+5x^3

Here's my setup
p(x)= 5, my determinant was not 0 therefore does not span
p(x)= 5+5x^3 same thing does not span

Now where do I go from here?
The answer is
p(x) = -2(1+x)+2(x+x^2) + 3(1-x^3)

where does -2,2,3 come from I think I setup my matrix wrong

>>7704495
>>7704475
holy shit I just figured it out thanks man

I took it to reduced row echelon form

It gave me
1,0,1,1
0,1,-1,-1
0,0,1,3
0,0,0,0

x3 = 3 so I plug back into x2 = 3+-1 =2
x1 =1-3 = -2

Therefore c1= -2, c2= 2, c3= 3 so I just plug back

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With an simple equilibrium problem like pic related, the normal force should inherently be acting at the angle theta right? Just want to make sure.

>>7704521
My nigga, what does normal mean? Does that look normal?

>>7704527
Its from my spirit science class

>>7704521
No. You should insert forces for every prescribed motion. The beam is prevented from going into the wall, so you add a horizontal reaction force. If there is also friction that prevents sliding, then you would add a vertical reaction force as well.

This is why we call them reaction forces, they are the reactions of some prevented motion.

If the beam was prevented to move in the theta angle, but was freely allowed to move orthogonal to theta, then you could add a force N as in your drawing.
Clearly not the case here.


You can reverse this question by asking:
"What directions are the nodes allowed to move in?"
Draw in these in, and the directions you didn't draw are the ones where you must have reaction forces.

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The stress in part a would be transverse shear, correct? If so, would the shear not be 0 since the points are on the edge of the part?

I got a new job which will give me a 20k raise, 1% more 401k match, the possibility for an annual bonus, and 1 more week of vacation days

I have to give notice to my employer tomorrow since I start the first week of January. I'm freaking out since I'm very valuable to my current employer and they won't be happy to see me leave. They will most likely start asking questions about why I'm leaving, why I wasn't vocal about wanting to leave, or perhaps give me a counteroffer.

How can I calm myself down and am I having any incorrect thoughts about the whole thing?

>>7704552
Thanks. I was trying to avoid adding extra terms that would make the system of equations unsolvable, but it seems like it might work out in the end anyway.

>>7704583
That's a strange way of putting it. You can't choose these things, and if you have done it correctly, but can't solve it, then you have a statically indeterminate problem. Anyway, you avoid that node anyway by using the moment balance about that node, as to not introduce more unknowns then you need (i.e. cleverly picking the balance equations you use). But there is no wrong way to pick those, just slightly lengthier ones.

I have a project on real life applications of interpolation and I can't think of anything to do. Can anyone help?

>>7704564
The shear stress will be zero at A and B, yes (typical quadratic shape)

The normal stress you compute as usual s = M*x/I + N/A

I don't get what you mean by
>The stress in part a would be transverse shear, correct?

>>7704564

I was just referring to question a. Thank you.

Suppose I have an homogeneous system of linear equations [math]\mathbb{A} \vec{x} = \vec{0}[/math]. How can I prove that the set of solutions to said system is equal to the kernel of the matrix [math]\mathbb{A}[/math]?

>>7704643
Google

>>7704718
Isn't that the definition?

>>7704746
That's what I thought too, but apparently I have to prove it, that's why I'm stumped

>>7704718
Erh. isn't that basically just the definition of ker(A)?

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I've asked this before, but I think I've finally figured out how to properly explain what I'm asking about.

From Observer C's reference frame, Observer A is moving to the right at 70% of the speed of light, and Observer B is moving to the left at 70% of the speed of light.

From Observer A's reference frame, Observer C is approaching at 70% of the speed of light, and Observer B is approaching at about 94% of the speed of light.

This creates a discrepancy. From Observer C, the DISTANCE between Observers A and B is shrinking at 140% of the speed of light, but from Observers A and B, the distance is only shrinking at 94% of the speed of light. This means that Observer C sees a higher-speed collision than what Observers A and B see.

However, it's a single collision. It's a single event. A collision that happens at almost 50% of the speed of light faster than another collision would have different outcomes and effects, therefore, there must be some mathematical component I'm missing that would make the collision actually be the same to all observers.

What am I missing? How is this conflict resolved?

>>7704752
>>7704746
Would you mind telling me if the proof I tried to make is correct?:

The kernel of a ilnear transformation [math]L : V \rightarrow W[/math] is defined as
[math]ker( \mathbb{T} ) = \{\vec{x}\ |\ T(\vec{x}) = 0\} \qquad \vec{x} \in V[/math]
On the other hand, the solution set for a homogeneous system of linear equations is defined as
[math] S_H = \{\vec{y}\ |\ T ( \vec{y} ) = 0 \qquad \vec{y} \in V\} [/math]
Therefore, it is easy to note that [math]ker(T)=S_H[/math]

>>7704864
Shit, that linear transformation is supposed to be [math]T:V \rightarrow W[/math]

>>7704864
You must have misunderstood the question or something, this is retarded (but correct)

>>7704872
I didn't, really; I have the document right in front of me and that's what it says. But I agree, it is very basic.

guise where can i get a free copy of iOS? I want to run it in a virtual machine.

>>7704896
oops i thought this was /g/

Are Engineers as smart as Physicist?

How do I calculate the probability of getting heads/tails two times consecutively in a series of 8 coinflips.
I'm looking for an explanation, not just the answer.

How hard is the math within a non-math class compared to an actual Math class? For example, Engineering, Physics, etc.

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I'm stomped. I have no clue how to prove by induction that these two recursive functions are equivalent. For a moment I thought I had it, but doing the following

g(n+1) = g(n) + (f(n+1) - f(n))
.
.
.
= 2*g((n+1) - 1) - f(n-1) + 1

For a moment I thought that maybe I would be allowed to change f(n-1) to g((n+1)-2), and I would have got the result I needed, but I'm pretty sure it wouldn't make sense to have in your induction hypothesis that f(n) = g(n) AND f(n-1) = g(n-1).

halp.

>>7705199
Can anyone pls help?

>>7705219
assume g(n-1)=f(n-1) and g(n-2)=f(n-2)
also, note f(n-2)=f(n)-n-(n-1)

then g(n)=2(g(n-1))-g(n-2)+1
=2(f(n-1))-f(n-2)+1
=2(f(n)-n)-(f(n)-n-(n-1))+1
=f(n)

>>7705286
Wouldn't that go against the point of a proof by induction? I thought that using such an hypothesis

g(n-1)=f(n-1) AND g(n-2)=f(n-2)

was a fallacies, rendering the proof trivial.

Why do I keep getting banned when I ask people to stick to empiricism and epistemology when discussing science topics?
Oh, right. Mod is a psychology student.
LULZ.

>>7705298
Nah bro its fine, but you need to show that f(0)=g(0) AND f(1)=g(1) to be fully rigorous.

Then if P(n) is the proposition that f(n)=g(n),
P(0) and P(1) imply P(2)
P(1) and P(2) imply P(3)
P(2) and P(3) imply P(4)
etc

>>7705304
Thank you so much man.

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Math major starting physics here.
A lot of this stuff I'm doing feels 'unjustified' or completely out of the blue, so to speak. A whole lot of this stuff seems really unintuitive to me. I've memorized all of the formulae and stuff, but I don't know the motivation behind most of it.
I'm not entirely retarded because I passed analysis.
So, how do I build intuition for physics? I did boatoads of problems per recommendation by professor, but I never got past the plug-n-chug thing.
Professor just says keep working on it.

Any help at all would be appreciated, but I would like something that explains the derivation of the formulae, and maybe a little history and insight as to why the derivation was done.
I know in academia (especially mathematics) this sort of thing is rarer than unicorns, but I am confident at least an intuitive introduction to thermodynamics exists somewhere.

Also I would appreciate any other tips for studying physics from a math major perspective.

Help a babby please?

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can someone please just tell me if what i did is correct?

answers in next post

>>7705408
Thermo should be alright but maths majors tend to hate qm because there are no derivations really

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I'm just not sure I fully understand this

>>7705432
>>7705429
plz

What's the difference between density and gravitational waves and which one surpasses the other one in speed.

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Where the fucking fuck did I fuck up?

>>7700901
I'm starting apostol's calculus today, what should be my approach? (also starting sears zemansky physics)

Question 1A: The soil consists of 3 ‘phases’. Under which condition does the soil
consist of two phases? Is it possible that the soil only consists of one phase?
Question 1B: A soil volume of 0.33 high x 1x 1 m has at the moment a water content
of 50 mm. At saturation the soil water content is 158.4 mm. What are the porosity and
the soil water content at the moment expressed in %?

>>7705545
no one can read this

if you never published during a research internship, does it mean you never did the internship?

Is the term "transforming" only used when changing a voltage through induction? Like you couldn't use it when describing a voltage regulator?

>>7700901
How long will it realistically take me to find a decent job if I drop out of my PhD in Physics right now? I don't want to get into teaching or programming. Ideally I want to do something to do with project management or sumin'...

>>7705550
y is equal to log base twenty five of e to the x minus log base five of the square root of x

the derivative of y is equal to (x times log base twenty five of e) minus (one half times natural log of x over natural log of five)
=
(log base 25 of e) minus (one over two x times natural log of five)
=
(log base twenty five of e) times (one minus (one over x))

>>7705616
Looks fine to me. Check with wolfram alpha

>>7702626
C
Make games.

>>7705645
then why the fuck did I get marked wrong?

>>7700942
Install Debian, then install KDE

I'm in Calculus 3 (vector/ multi-variable calculus) and people I'm in class with all mention they've taken Linear Algebra already, and I see in uni degree tracks that have linear algebra before vector calculus and differential equations. Is this something I should be concerned about? Am I missing the benefit of whatever Linear Algebra is.

>>7700901
Does environmental temperature affect the spreading of odor?

>>7705659

Maybe because it looks like autistic scribble

>>7702626

C should be your first language. Dont make it your main language if you find it annoying though, it's not suited for general programming where speed and fine control is not nescessary.

Someone asked me for help with this:
Solve for x
[eqn]y=\frac{\left(\frac{1}{\sqrt{\left(1+x^2\right)}}-1\right)}{x^2}[/eqn]
We're not sure if it can be done.

>>7705754
What I mean is express x in terms of y.

>>7705688
Lower-division multivar calc, LA and diffeq all sort of go hand in hand, whether you're studying coordinate transformations as changes of basis on some linear space or applying them to solve integrals, or solving linear ODEs/linearizing nonlinear ones about arbitrary points etc (See Apostol vol 2.)

I wouldn't be worried unless your class has LA as an actual prereq that you had to get approval override.

>>7705763
This. If you can do basic vector arithmetic, find the determinant of a matrix, and describe some basic objects parametrically you should be fine

>>7702626

Other anons suggested C, and C is a very useful language to learn, but I really don't think it should be someones first language.

I learned python, then C, and most do C++ now. Like the other anon said, C is good when you need really fine control of everything. Learning C first is like learning math purely by proof. You're gonna get a really good handle on things, but it's a lot harder than it needs to be for your first exposure to the subject.

You can google "Learn Python the Hard Way", there's also "Learn C the Hard Way". I'd recommend python.

There's websites like code-eval, hackerrank, and ProjectEuler to keep to busy while you learn it, too.

>>7705770
>>7705763
Thanks, nerds. I guess I'm fine then.

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>>7700901
Sup /sci/ im currently in my last year Bachelor computer sience (college level, not uni (eu system))
I want to get a Msc in comp sience next year but in order to do that i need to take a pre-master to get to the level of
uni. This pre-master is kind of like only math.. Since im only mediocore in math im wondering if im going to make it,
will I, /sci/ ?

>>7705886
Not with that attitude! There's no reason to be scared because you have a pile of work ahead of you. Get motivated. Don't see the math as a chore. Math is fucking beautiful and if you don't get into the mindset of knowing that it's hard, rewarding work and wanting to do it you aren't gonna make it.

>>7705896
I like doing math tho!
Thanks anon, your motivation helped!

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>>7700901
just dun goof'd my calculus exam. the task involves a limit (x -> inf), but i cant wrap my head around this step. seriously, how the fuck does it work?

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if im capable of doing a pure math degree but hate it, should i transfer to applied (what is actually fun for me)?

>>7705901
You're gonna make it bro.

I don't know exactly what math you need, but here:
http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-042j-mathematics-for-computer-science-fall-2010/index.htm
And check out the other course offerings in that same website.

>>7705918
Yes. Obviously.

>>7705923
just dont wanna be the cop out boy

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3014632277

3016976996

>>7705912
For example:
[eqn]\frac{\sqrt{x^2 + 1}}{x} = \frac{\sqrt{x^2 + 1}}{\sqrt{x^2}} = \sqrt{\frac{x^2 + 1}{x^2}} = \sqrt{1 + \frac{1}{x^2}} = \sqrt{1 + x^{-2}}[/eqn]

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>>7705934
i love you! here's a great gif in return

>>7705926
do what you like, stop being ridiculous

>>7705926
You're a cop out boy if you transfer because it's too hard for you. If you CAN do pure math but find applications more personally interesting, you're no less of a person for pursuing your interests.

If you feel at all insecure about it, though, you should either make sure you have an excellent (A) average in pure math when you switch out or learn to get the fuck over yourself.

>>7705943
That dog has aspergers

>>7705721
why did she circle the base 25?

>>7701102
Always easy compared to the real class.

>>7705616
>>7705645
W|A is saying it's (x-1)/(x log(25))

having a tough time figuring out where you messed up though so just look through this lel
https://www.symbolab.com/solver/step-by-step/%5Cfrac%7B%5Cpartial%7D%7B%5Cpartial%20x%7D%5Cleft(%5Cfrac%7B%5Cln%5Cleft(e%5E%7Bx%7D%5Cright)%7D%7Bln%5Cleft(25%5Cright)%7D-%5Cfrac%7Bln%5Cleft(%5Csqrt%7Bx%7D%5Cright)%7D%7Bln%5Cleft(5%5Cright)%7D%5Cright)/

>>7702867

>if you have an empty set there is still one way to arrange it

But the act of arranging requires at least one element,no?

>>7706074
we defined the factorial function arbitrarily, and the choice was f(0)=1

>>7706093
Oh.. Yeah, I forgot I signed that shit.

>>7706128
The point is that if you want to use an unconventional function which starts at 0 and otherwise is the factorial, you can just invent some other notation and fucking do it.

The function you're asking about starts at 1 and that is literally all there is to say.

Does M-theory really predict that something can spontaneously arise from nothing? And is there any hope of it being proved finite?

Is every rational number a boundary, an accumulation point of Z, or both?

>>7706219
Z the set of integers does not really have accumulation points

>>7706249
and also no boundary points?

How do I study for a math test.

I have my math final in a week and im really worried and stressed

>>7706254
Not sure what your definition is for those but basically you can't converge to anything in Z in a nontrivial way

>>7706279
https://en.wikipedia.org/wiki/Boundary_%28topology%29

>>7702175
You'll probably want to make a binary classifier. Logistic regression would be a good starting point. Andrew Ng's class on coursera can help you with the theory, but if you need a more hands on approach with programming then look up a tutorial using matlab.

is something increases by 80% every 3 years, how do I find out by what percent it increases a year?
do I divide 80 % by 3?
pls halp, and provide explanations as to why it works

>>7705954
Dogs have an underdeveloped neocortex, by definition ALL dogs have asperger

>>7706314
I think you need more information
If it's proportional, yes, you can divide 80/3. But it can also be 1% first year 1% the second and 78% the third
I never got interested in math so sorry if I'm wrong

>>7706303
OK, so in the normal topology (induced by R) Z has empty interior so the whole set is the boundary

>>7706326
it doesn't matter what happens in real life, because either way, if modeled correctly, the result will be the same as if it happend in real life

>>7706327
ok, thanks, so that should mean that all rational numbers are not boundary points of Z.

>>7706353
unless they are members of Z, that is

>>7706318
Then why does mine run and catch the frisbee like a filthy normie?

>>7706353
You can characterize the boundary of [math]Y\subset X[/math] as all points [math]x\in X[/math] such that for all neighborhoods U of x, we have [math]U\cap Y\ne\emptyset[/math] and [math]U\cap (X\setminus Y)\ne\emptyset[/math].

You should be able to convince yourself that the boundary of Z is exactly Z .

>>7706410
Not under the trivial topology

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How's my chances of getting into a CC class when I'm on the waitlist?

>>7706486
He said subspace topology. Why would you think it's necessary to point out that the trivial topology is pathological?

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How do they come up with that as the derivative for g(t)?

I plugged it into Woflram Alpha and get the same derivative as in the pic, but whenever I do it I get g'(t) = e^(-3t - 1)

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I know this is elementary to must of you but pls help

>>7706557

Pic is same as writing (x^4)^1/4 = x^4/4 = x^1 = x

>>7706562
Yeah i was over thinking it.

There's a property that states that:

nth root of A^n is just |A|, if n is even.

>>7706557
4th root of x = x^(1/4)
so you have x^((1/4)*4)
i fucking love math lmao

>>7706604
It's the absolute value of X, not just X

>>7706606
kind of debatable and arbitrary

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Is this correct or have I fucked up sonewhere

>>7706624
no that's x^9 so you're right

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>>7706632
Yay. What about this

>>7706640
looks perfect

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Would a nearby star like Alpha Centauri share its Oort Cloud with Earth or would it be distinct?

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>>6947
Can this algebraic expression be simplified any further?

>>7706689
You're denominator is incomplete, it's supposed to be 8x^7+8x^6+1.

>>7706696
Oh yeah, I forgot the coefficient of X is 1

>>7706689
>>7706696
maybe i'm wrong but i thought you could only add values to both sides of an equation, if you are dealing with a rational number the most you can do is multiply the numerator and denominator by 1.

(x^-2 - 1) / (8x^7 + 8x^6) will work just as well as (1 - x^2) / (8x^9 + 8x^8) if i'm correct.

i plugged x = 2 into your original formula (x^1 - x) / (8x*8 + 8x^7) and got -1/2048, but i got -1/3072 from your simplified answer.

>>7703023
Bumping for this

>>7706667
It wouldn't. That's on a log scale, which means alpha centauri is much farther away than pictured.

>>7705491
>still no one
wow thanks guys

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>>7706640
>>7706656

>>7706837

I understand that part, but how far away from each other would they be? Would there be no chance of them trading material?

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Why do we often portray artificial intelligence as ultimately malevolent in fiction?

>>7706960
Two things:
-We all intuitively understand that from an objective standpoint we're disjointed, inefficient, and self destructive. Mankind has always feared higher judgement and punishment for its nature.
-AI is uncaring. It doesn't share our nature. It just does what it's designed to do, and that's it. Any given error in design, or unforeseen functionality, and suddenly it's doing things you don't desire. And it won't stop. It's doing what's rational, not what's emotionally or subjectively pleasing. It likely can't be reasoned with and will need to be stopped by force.

Think of it like jinn. It will perform the processes you wish for, but might take it to literal and logical consequences that weren't intended. This is due to its lack of self and personal desires and drives. It would seem trying to engineer these in would be preferable in the case of even a specialized AI. Then you get some Asimov-esque shit where it kills you because it loves you or something. Very delicate.

>>7700901
What happens when you mix silicon dioxide and citric acid. Organic chemistry is something I plan on teaching myself in the next year or so.

>>7706919
What?

>>7706977
>-AI is uncaring. It doesn't share our nature. It just does what it's designed to do, and that's it. Any given error in design, or unforeseen functionality, and suddenly it's doing things you don't desire. And it won't stop. It's doing what's rational, not what's emotionally or subjectively pleasing. It likely can't be reasoned with and will need to be stopped by force.
you could've shortened this to "i don't know what's AI" and go back to your cartoons

>>7706960
because they are incapable of humanity since they aren't human.

>>7706624

root x to the 4th power is x^2

square root can be rewritten as anything to the power 1/2

>>7706989
Oh so I made some unnecessary steps

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I need to spend the next 12 hours from now, 10pm to 10am studying for my College Final. What is something that will keep me awake without causing my heart to feel strange & nervous?

I have coffee which makes me nervous.
I have apple cider which I don't think is chemically wake-up juice in anyway, but a good sip out of that always wakes me the fuck up in the morning, but I'm afraid that will cause me to feel nervous and distracted.
Are there any common house-hold stimulants that can wake someone up without causing your heart to feel nervous?
If NyQuil makes you sleepy does DayQuil do the opposite or something?

>>7706977
>It just does what it's designed to do

Can it be truly an AI if it only functions in a way that it was programmed to be?

If it doesn't have a choice why it call it intelligent?

>>7706919
What's so fucking funny?

>>7706994
>implying choice and free will exists in humans
LOL

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>>7706960
I could not help but notice your png was not optimized anon.
I have optimized your png.
Your png is now optimized.

>>7707031

Optimized in what way?

>>7706984
Very substantial response.

>>7706994
Humans are machines. The experience of choice is likely an illusion.

>>7704791
>> From Observer C, the DISTANCE between Observers A and B is shrinking at 140% of the speed of light

no reference frame observes anything moving faster than c, that's why relativity works the way it does.

>>7707043
>Humans are machines. The experience of choice is likely an illusion.

I disagree.

The fact that we do all sorts of things that are outside of our nature prove that we are more than millions of years of evolutionary programming.

That fact that we can voluntarily commit suicide have sex with people we are not attracted to go on hunger strikes, the ability to go against every biological impulse we have says to me that we are more than just biological machines.

>>7705154
you flip 8 coins
total number of possibilities for heads/tails is 2*2*2*2*2*2*2*2 = 2^8 since each flip has 2 outcomes

possibility for 2 consecutive heads/tails: out of the 8 spots, choose which 2 are heads/tails this can be done 8 choose 2 ways. For the remaining 6 spots, there are 2^6 ways to arrange them.

probability = 8 choose 2*(2^6) / 2^8

>>7707056
>we do all sorts of things that are outside of our nature
We don't. Those things are part of our nature. ie, the total spectrum of things we can be, do, and become in any given instant.

We're a type of machine. This is within the affordances of the machine's parts relative to its environment.

>>7705408
I used to be a physics major, but I like our maths department much more.

When you work on physics problems, don't get stuck on the plug and chug stuff, just know a few properties about the system you're working with. Whether it's mechanics, QM, thermo, there's a handful of properties about those systems which when brought together in some context give you a straightforward way of computation. Similar to working through proofs.

If you're taking something like physics I or II it will feel out of the blue because more rigorous approach to those subjects involve mathematics beyond calc I and II, which most people taking those classes won't have.

>>7705408
idk, however, i googled 'build intuition for physics' and there was 480,000 results.

>>7705432
literally all you do for final velocity of inelastic collisions is add up the momentum of the two objects and divide by the sum of the mass. It is clear from the table that this is what is happening.

1 x 2 + 0 / 1 + 1 = 1
1 x 3 + 0 / 1 + 2 = 1
since all of the momentum is in mass 1, divide momentum of mass 1 by the mass of both objects which is what the table did

if p20 in the table was nonzero, you would add that to p10 before dividing by (m1 + m2)

>>7707066
samefag

this is only valid if the question is asking for at least 2 heads or at least 2 tails

if it's at least 2 heads or tails you have to multiply the previous solution by two

if it is exactly two, then you have to partition the set of all possibilities into equivalence classes, and i'm too tired to do that. look up inclusion-exclusion if you need to use it.

What is an object in CS? Like object oriented programming? Is it a set with some added structure? Or is it something else entirely? I've had a little higher math but never studied anything CS related

>>7707128
It's programming with a set objective, or object. It's like your setting out to complete a goal.

>>7707128
a class is a set of related data, an object is an instance of a class. don't overthink it, it's just a way to structure data to make programming a bit more efficient, easy, and intuitive.

cars are a class
your car is an instance of that class

can you physically modify the concept of a car? no, and similarly you cant perform methods on a class
can you physically modify your own car? sure, and in object oriented programming you can perform methods on an object as well.

>>7707128
nothing more than a set of properties. The computer maps the properties in continuous memory so order matters on a hardware level but not software. But if youve never studied CS the implications of this mean nothing to you.

Hell you could implement this to an extent in python with a dictionary.

Greetings, /sci/. I come to you for some guidance.

I've found myself stuck with a shitty group for a project worth a huge percentage of my final grade, and I have supporting evidence that I've done my fair share of the work. Now, what is the standard procedure for getting grades exempted? Do I provide evidence of my efforts to my professor? If he refuses, what then?

I also would like to know if my grade exemption will be a private matter, ie. my group mates won't find out. I'm afraid of how they'll react if they do. Thanks, /sci/.

How do I get good at studying?
Like, how are people studying to get their A's and B's? Waking up and putting in the time is not the deal but in terms of self-testing, truly (!) understanding the material, note taking and exam preparation I don't know any better. I never worked straight out of a book as well.
So, what can you tell me so that I will have a better academical life and will less suffer?
Thus, what would you tell me to help me on those matters?

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>>7700924
>I will sudoku

Why the fuck did I laugh so hard at this

>>7707253
because you're new

How can I dedicate my life to science? What are the most exciting fields in science at the moment?

>>7704414
Sound is a density wave. Think that over

>>7707234
If they're simply not doing their share of the work, then talk to your professor long before the project is due. You should have been doing this a month or two ago, when it was clear they weren't doing their bit.

If they're struggling with their bit, but have been putting in time at it, then you need to help. That's why there are group projects. It's not so you can just split off pieces and do less work. The idea is that you understand the entire thing, not just that arbitrary little piece you took.

If it's the day before the project is due, and you were planning on cobbling it all together at the last moment, then that's your fault. Hand it in, talk to the professor and explain, but don't expect anything.

You won't get an exemption, but professors can assign whatever grades they want. If it looks like you've done A quality work, but your project as a whole is a C project, you may still get an A.

> private matter
Your professor will never discuss your mark with another student.

It takes me 2-4 hours to do a program in c++. How do I get better and faster?

>>7707376
I would say keep practicing but you really scream being at a state where you really haven't learn anything yet. Go check an introduction to programming class or an algorithms class in ocw.mit.edu

>>7707384

I'm in an introduction to c++ right now. We are barely learning about pointers. I'll check out the algorithms class in mit.

>>7707376
how big is the program/what is it about?

>>7707386
I think the problem is you're learning the language by itself, not as a means to an end. Try to make nice things with it, check out easy problems at codeforces (div2 A/B)

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>>7707397

Pretty small. Any person on /g/ can probably do it in a minute. I understand what the problem wants me to do, but I just have trouble with applying the tools to create what the problem is asking.
Not sure if code works here, but here's one that took me two hours.
[code]
#include <iostream>
using namespace std;

void function(int [], int, int);
int main(){

int nTerm[3] = {0, 3, 5};
int input;

cout << "Type an n-term and I will display all terms larger than n. \n";
cin >> input;

function(nTerm, 3, input);

return 0;
}
void function(int array[], int SIZE, int n){

for (int i = 0; i < 3; i++){
if (array[i] > n){
cout << "Larger: " << array[i] << endl;
}
}
}[/code]

Getting the void function to act like how I wanted took me over 30 minutes.

>>7707306
Good to hear anon, thank you so much for your help.

>>7707398

I use the college book Tony Gaddis.
http://www.amazon.com/Starting-Out-Control-Structures-Objects/dp/0133769399/ref=sr_1_1?ie=UTF8&qid=1449558799&sr=8-1&keywords=tony+gaddis+c%2B%2B

>>7707411
Ugh. Frankly this seems pretty terrible, these kind of books usually are. I would really advise you to go read K&R if you want to learn from a book (it's C, not C++, which is going to give you way better habits), and again, learning the language as a means to an end (and algorithms class is my top pick).

>>7707418
Why do lines on a horse shoe magnet increase in density towards edges

>>7707066
I did it another way. There's two possible solutions which would not present two consecutive heads/tails, so i basically took
[math]((2^8)-2)/2^8[/math]
Would that be correct?

>>7707445
Yea that way is much better dunno what that other guy is thinking

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I've got to solve this, but it was not given that the function is continuous, how do I show that? I know the solution from there on.

>>7707690
Assume the function is not continuous, what would happen considering what was given?

Why does Saturn have a hexagon on its butt?

Let [math](X, T)[/math] be a topological space, and let [math]1 \leq i \leq n, \; f_{i} : X \rightarrow \mathbb{R}[/math] be the coordinate functions of a function [math]f := (f_{1}, ..., f_{n}) : X \rightarrow \mathbb{R}^{n}[/math]. Prove that f is continuous if and only if the coordinate functions [math]f_{i}[/math] are.

I have a problem understanding just how the coordinates functions act with regards to the topology. I know I must prove that for all open sets U with regards to the Euclidian metric, the pre-image of U onder f in X is open. But say I take a random U and inspect [math]f^{-1}(U)[/math], how can I prove that for just one of the [math]f_{i}[/math], [math]f^{-1}_{i}(U)[/math] is open in the topology T?

So, I am doing the exercises in introduction to linear algebra.
I have the feeling that I am very rusty...

I have shown geometrically that the column vectors (1,2,3) and (3,6,9) are filling a line.
that is, that they do not cross each other or something, but are overlapping on the same line.

I used the formal linear combination (cv + dw) and then manipulated c and d so that I got the origin (0,0,0) as a proof of it being in the same line.


Is there a mathematical way of showing how to find out if the vectors fill out a line, a plane or R^3?

>>7707878
They do not just "fill a line", they are coinciding lines. You can show just by proving every point on the line defined by 0 + λ(1, 2, 3) also lies on 0 + μ(3, 6, 9) and vice versa which is easy as (3, 6, 9) = 2 * (1, 2, 3).

>>7707878
>>7707894
And oh, yes, you can prove a set of vectors span a space like for example [math]\mathbb{R}^{3}[/math]. A base of this space consists of three linearly independent vectors (Google this), and every such set is a base for this space. You could also prove every vector in a space can be written as a linear combination of the vectors in the set.

>>7706534
i didnt
lol

Anyone give me a hint?
Any Set of 5 integers (1, 2, 5,7, 11)

There are 3 integers that have a sum that is divisible by 3. (2, 5 ,11)

Why does this work? I tried figuring out with evens and odds but came to a dead end.

yes its babby proof, that just makes it easier for you right?

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I'm well aware math isnt my thing but I've been going through some workbookw in my free time because I'm bored and would like to get back into a community college
Here's the problem I'm on. The way this book I downloaded goes about calculating Shapley Shubik and Banzhaf power indeces is by listing the whole fucking thing. I've skimmed through the chapter again and I dont see a shortcut

For one with 3 voters [5:4,1,2] as an example, you're supposed to list everu single permutation by hand(ABC, ACB,BAC,BCA,CAB,CBA..). Do the makers of this book really expect people to do this by hand for a series of 10 voters or is there some shortcut yoh can use for this? I think so because all the other voters have the same value, but as I said math isn't my thing

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How can I make mercury or another liquid metal attract to a magnet?

I'lll take literally any answer including making another alloy or anything that would work

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Can someone help me out with this? It says to express your answer symbolically

>>7707839
A general topological space has no metric, let alone the Euclidean metric.

>>7708782
And if we for now assume [math]\mathbb{R}^{n}[/math] is endowed with the Euclidian topology? I said metric when I meant topology, my bad.

hey guys.

I was thinking of doing diff. equations and linear algebra at the same time next semester.

Im taking calc 3 right now.

From what i've been reading these classes don't seem too difficult. But from /sci/'s personal experience, how did you guys feel about taking them at the same time?

>>7708816
I dont really understand what your calc 3 curriculum contains if you havent had linear algebra yet. Isnt calc 3 vector calculus?

The differential equations course at my uni required a lot of knowledge of real analysis and linear algebra, for what its worth.

Live you fucking thread

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When reviewing for some calculus II series stuff, I noticed my teacher did pic related to a telescoping series

Can someone explain what the fuck he did?

Is this some shortcut I forgot about or did he do something else?