Leave these fields empty (spam trap):
You can leave this blank to post anonymously, or you can create a Tripcode by using the format Name#Password
[i]Italic Text[/i]
[b]Bold Text[/b]
[spoiler]Spoiler Text[/spoiler]
>Highlight/Quote Text
[pre]Preformatted & Monospace Text[/pre]
[super]Superset Text[/super]
[sub]Subset Text[/sub]
1. Numbered lists become ordered lists
* Bulleted lists become unordered lists



Helpful Youtube channels by Cyril Gebblecocke - Thu, 04 Jun 2015 09:55:27 EST ID:jNXUmpxk No.14775 Ignore Report Reply Quick Reply
File: 1433426127702.jpg -(104903B / 102.44KB, 750x720) Thumbnail displayed, click image for full size. 104903
Hey /math/,

I'm taking a satistics course this summer to fulfill my last credit for community college, and I was wondering if you guys know of any good Youtube channels to help me out through. We're currently going over probability, and it flew right over my head.

Cyril Gebblecocke - Thu, 04 Jun 2015 09:57:20 EST ID:jNXUmpxk No.14776 Ignore Report Quick Reply
help me through this*

tired, sorry
Nicholas Bundlekire - Thu, 04 Jun 2015 21:08:37 EST ID:7QJ+5Rkj No.14777 Ignore Report Quick Reply
khan academy
Nicholas Ducklock - Thu, 02 Jul 2015 09:35:59 EST ID:kOuj74f1 No.14810 Ignore Report Quick Reply
this guy help me a lot last summer when i was studing statistics.

Good Ideas Thread by Nakura !xMsGPnYjBI - Sun, 28 Jun 2015 17:45:04 EST ID:NAU1L+Of No.14808 Ignore Report Reply Quick Reply
File: 1435527904730.jpg -(75565B / 73.79KB, 1280x853) Thumbnail displayed, click image for full size. 75565
Fourier analysis applied to violent events and plotted on a complex plane could assist in finding the root cause of violent events and prevent their occurence in the future. Wave dispersion field devices, in the future, could prevent violent behavior, by taking advantage of wavelengths determined by psychodynamical theory and data, and influencing neuronal firing patterns in the brain. It would work similarly to how radios already work, but calibrated much more carefully.
Frederick Nullyman - Mon, 29 Jun 2015 23:19:30 EST ID:rS9AJec8 No.14809 Ignore Report Quick Reply

>the root cause of violent events

jolly african-americans.

>prevent their occurence in the future

Remove watermelon.

Passed test slayer by Martha Pullerkitch - Sun, 17 May 2015 12:48:46 EST ID:muTtSqY/ No.14736 Ignore Report Reply Quick Reply
File: 1431881326142.jpg -(90587B / 88.46KB, 689x891) Thumbnail displayed, click image for full size. 90587
What's up /math/, I just got 84% on a test I was really worried about fuck yeah. But one question I couldn't answer, it seems like it's insoluble, can you help me out?

A rocket is traveling through space at a speed of 7500 m/s. If in one second it burns 710 kg of fuel, what is the change in momentum during this time interval in kg m/s.

Don't you need the exhaust velocity of the rocket to solve this? Thanks
2 posts omitted. Click Reply to view.
Jarvis Bardson - Wed, 17 Jun 2015 18:05:29 EST ID:x6xydNWl No.14800 Ignore Report Quick Reply
Guys, look at the units. Momentum is Mass x velocity. Velocity is fixed, change in mass is given. Find change in momentum.

Unless I'm missing something, this seems like a straightforward elementary physics problem.
Jarvis Bardson - Wed, 17 Jun 2015 18:08:54 EST ID:x6xydNWl No.14801 Ignore Report Quick Reply
Nathaniel has the right of it. Sorry I didn't see that sooner.

NB for double post.
Cedric Dubbersare - Thu, 18 Jun 2015 12:28:42 EST ID:nyIjuDfA No.14802 Ignore Report Quick Reply
1434644922866.jpg -(910642B / 889.30KB, 1440x2560) Thumbnail displayed, click image for full size.

It's a "restate the momentum equation" kind of problem. You're calculating the change in Momentum"dM" over a given time period "dt". Naturally, we all remember that momentum"M" is given by mass"m" times velocity aka: M=m*v. We're given both the velocity"v" and the change in mass"dm" over a period of time"dt" so the equation looks like "dMomentum/dt = dmass/dt * v" fortunately for us, the "dt"s on both sides of the equation have a value of 1 second and can be ignored because anything/1=anything. this problem is now a simple multiplication problem: "dM = -710kg * 7500m/s" which anyone may plug into a calculater at their leasure.

Good night, sweet prince. by Barnaby Drapperstat - Sun, 24 May 2015 14:29:23 EST ID:z/dIPyff No.14746 Ignore Report Reply Quick Reply
File: 1432492163853.jpg -(193654B / 189.12KB, 567x855) Thumbnail displayed, click image for full size. 193654
John F. Nash Jr., a mathematician who shared a Nobel Prize in 1994 for work that greatly extended the reach and power of modern economic theory and whose decades-long descent into severe mental illness and eventual recovery were the subject of a book and a 2001 film, both titled “A Beautiful Mind,” was killed, along with his wife, in a car crash on Saturday in New Jersey. He was 86.
5 posts and 1 images omitted. Click Reply to view.
Nicholas Chingerperk - Thu, 11 Jun 2015 13:14:16 EST ID:QIXSgr8C No.14790 Ignore Report Quick Reply
media didnt make as much of an event of it
Basil Sasslehut - Fri, 12 Jun 2015 23:48:17 EST ID:rp0UlP7W No.14794 Ignore Report Quick Reply
It's just weird, even my friends who are mathematicians didn't say anything about it but posted something about John Nash. I guess it's amazing what a movie can do to public perception. No disrespect to Nash I'm just kinda bummed that Grothendieck wasn't appreciated when he was one of the greatest mathematicians of the 20th century.
Fanny Soddlestut - Sat, 13 Jun 2015 21:37:56 EST ID:QBhQLlLE No.14798 Ignore Report Quick Reply

No one can deny that Nash was more well known than Grothendieck. Not to disparage Grothendieck, but I think Nash focused on much more practical and "relevant" areas of mathematics such as game theory and computer science, which is interesting to everyone, while Grothendieck was more of a specialist in the field of Algebraic Geometry and Topos theory, which is niche. Nash also did excellent Algebraic Geometry.

Basically, Nash achieved more and had a more interesting story and received more attention as a result. They were both great mathematicians and their death is a huge loss, but Nash was a bigger deal for many reasons.

Drinking your wallet by Whitey Bomblefodge - Fri, 12 Jun 2015 02:09:00 EST ID:vX6Harxq No.14791 Ignore Report Reply Quick Reply
File: 1434089340591.png -(290633B / 283.82KB, 500x746) Thumbnail displayed, click image for full size. 290633
I thought this was a question for hooch, but I have a second thought here.

Say you pour a $8.00 bottle of vodka into a glass. You suddenly envision coins dripping out of the bottle. My question for you, what coin were you seeing?
Whitey Criffingbanks - Fri, 12 Jun 2015 05:32:17 EST ID:i84x+n57 No.14792 Ignore Report Quick Reply
1434101537564.jpg -(143308B / 139.95KB, 1024x768) Thumbnail displayed, click image for full size.
$8 for a 750 ml bottle? I'd imagine diarrhea dripping out, not coins.

Assuming we're talking about US currency and 750 ml bottles, using the penny - the coin with the greatest volume to value - you'd only fill the bottle up close to 2/5 of the way. This is assuming that the pennies sorta melt like the watches in pic related, which is a fair assumption considerring your wording. This way we don't have to worry about space between the pennies.
Whitey Criffingbanks - Fri, 12 Jun 2015 05:50:14 EST ID:i84x+n57 No.14793 Ignore Report Quick Reply
Clara Wennerfock - Sat, 13 Jun 2015 06:22:58 EST ID:YsOAl7K9 No.14797 Ignore Report Quick Reply
I'm assuming it's half that size. That sounds about right. It's cheap but might not make you go blind.

Anyway it's 2.13(recurring) cents per ml at that quality/quantity. Vodka is about 37% alcohol and a smidge of glycerine if it's that cheap. Glycerol is about 1.2g/ml water is 1 and alcohol is .789. Vodka can be up to 40% but by assuming it's cheap shit. Glycerine is like 5% and the rest water so 1 ml is .05*1.2g + .37*.789g + .58g

a cent has a displacement of about .0433ml while the current rate is about .46ml per cent so US cents are probably pretty appropriate actually.

If ti's a 350ml bottle it's probably dead on.

If you're that desperate to get drunk buy some cheap cider though. White lightning actually does taste like it's been through someone's kidneys already but it's got the same alcohol content in a 3 litre bottle as a quart of vodka and when I was young enough to be desperate it was about 1/3 of the price of the absolute worst vodka I could get that wasn't toxic and illegal.

fertilizer question by Isabella Blackforth - Fri, 22 May 2015 19:43:11 EST ID:YCs1tF7z No.14741 Ignore Report Reply Quick Reply
File: 1432338191011.jpg -(51219B / 50.02KB, 720x960) Thumbnail displayed, click image for full size. 51219
Hello /MATH/ I have a quick question for you to help me out with if that's cool.
Basically I just need to know how much fertilizer 20-4-8 would be in a 100lb bag
Betsy Pongerlock - Fri, 22 May 2015 21:34:36 EST ID:rw1aY/ny No.14742 Ignore Report Quick Reply
about 100lb
Phineas Hepperdock - Wed, 27 May 2015 23:45:30 EST ID:Jz+dW0dw No.14755 Ignore Report Quick Reply
Those are percentages.

Surely you know what a percent is.

<3 <3 by Jack Benninghat - Wed, 18 Jun 2014 06:38:10 EST ID:Fj/YvlCk No.14096 Ignore Report Reply Quick Reply
File: 1403087890404.jpg -(15466B / 15.10KB, 350x350) Thumbnail displayed, click image for full size. 15466
I love maths and I love you <3

Share whatever proof, trick, theorem, mathematical tool, number, or other maths-related stuff you like in this thread.

I like e. It's always felt a bit "blue" for me, you know 2.7182818284590452353... A nice deep blue.
67 posts and 19 images omitted. Click Reply to view.
Caroline Brebbermag - Fri, 15 May 2015 20:25:48 EST ID:K8qJv5EF No.14733 Ignore Report Quick Reply
1431735948243.gif -(715742B / 698.97KB, 440x330) Thumbnail displayed, click image for full size.

Hmm, to really understand the gravity of the spectral theorem, you'd need to have a pretty firm understanding of functional analysis, which in turn requires a firm understanding of linear algebra *and* measure theory.

For measure theory, probably the best beginner's book would be Royden's "Real Analysis", 3rd edition. Very clear language, motivates the study, etc. Be ready for some abstraction, though: measurable sets and functions are ill-behaved to say the least.

Once you understand the Lebesgue Integral, you'll be ready for functional analysis. There are many fantastic texts on the topic, but if you're *only* interested in learning spectral theory, you might want to try "Theory of Linear Operators in Hilbert Space," by Akhiezer and Glazman. This is a Dover book, and therefore very cheap. It covers everything from the basics of functional analysis (on inner product spaces) to the full spectral theorem for self-adjoint operators.

If you want a basic rundown of the spectral theorem, it basically says that very symmetric operations of certain kinds (like multiplication by a real number [boring] or the second derivative operator [interesting]) can be used to decompose certain vector spaces via an orthonormal basis, i.e. into a coordinate system where each axis is at "a right angle" with each other axis. This allows one to decompose your symmetric operation into a sum of very simple transformations on individual components. Like any other "decomposition" theorem, this is *extremely* advantageous when solving tough problems where these operators play a big role.

As for IBP, when combined with Sobolev spaces, it allows you to transform a second order partial differential equation into an integral equation of sorts. If your original PDE was linear, your integral equation gets alllll sorts of special properties (bilinear forms are what they become). This allows for really interesting theorems from functional analysis, like the Lax-Milgram theorem or the spectral theorem, to become immediately applicable to solving, or at least guaranteeing a solution to, your PDE. You *must* have Sobolev spaces for this approach to be sou…
Comment too long. Click here to view the full text.
Ian Noffingdock - Tue, 19 May 2015 15:35:08 EST ID:NCaB2rkH No.14738 Ignore Report Quick Reply
You've provided some great resources to look into here and a clear path forward Brebbermag, I thank you for it.
Caroline Murdbury - Wed, 27 May 2015 04:01:40 EST ID:96SVbDTc No.14753 Ignore Report Quick Reply
This is along the same lines as my little trick for squaring, will use the same number. I don't even remember where I got it from, I think my calc 3 teacher squared some big number with it and I thought it was really elegant.


As for my favorite thing, the bisection method of root finding is up there. Just a really really beautiful and simple way of looking at the problem. The idea of "just split an interval in half and figure out which half has the root in it, repeat" is just really neat to me.

Helpless dumbfuck calling for help by Sidney Passlenotch - Mon, 04 May 2015 16:43:13 EST ID:3dz0uQ7J No.14724 Ignore Report Reply Quick Reply
File: 1430772193140.gif -(2314B / 2.26KB, 388x298) Thumbnail displayed, click image for full size. 2314
Is a horizontal or vertical line that expands to infinity it's own asymptote? Or is this in this case not applicable and a really dumb question?
Phineas Hecklesot - Tue, 05 May 2015 10:18:46 EST ID:xOOOxXVr No.14725 Ignore Report Quick Reply
An asymptote is defined as a value that is approached but never reached. Y=3 reaches Y = 3, so it's not its own asymptote

nice question though
Reuben Chacklefield - Sun, 17 May 2015 06:24:17 EST ID:WtAxPZi7 No.14734 Ignore Report Quick Reply
1431858257260.png -(246045B / 240.28KB, 444x604) Thumbnail displayed, click image for full size.
tl;dr not really but I can prove otherwise

So consider the horizontal line y (x) = 3 i.e. y is independent of x, so for all values of x, y is always 3.
If x/x = 1,
then y (x) = 3 = 3*1 = 3x/x
It would still give you a horizontal line, but at x = 0 shit fucks ass.
You can then repeat this idea with other values like (x-1)/(x-1) = 1 so you get a "hole" at x=1, so on and so forth. Repeat this for all values of x and insert it into the equation then your line will be asymptotic to itself.
Shit Bottingbire - Sun, 17 May 2015 13:24:26 EST ID:xOOOxXVr No.14737 Ignore Report Quick Reply

An asymptote is a discontinuity, but not all discontinuities are asymptotes. What you just described is a function that is not continuous at all integer values of x, but not one with an asymptote.

I would also tend to argue that y = 3(x/x) is a different function from y = 3 simply because it returns different results

How can I relearn math? by Nicholas Cluzzleshaw - Sun, 26 Apr 2015 16:13:04 EST ID:L+X0k1Ap No.14703 Ignore Report Reply Quick Reply
File: 1430079184240.jpg -(9197B / 8.98KB, 267x181) Thumbnail displayed, click image for full size. 9197
Hello /math/. I have retrograde amnesia.
I've forgotten math essentially, so much so that my abilities have regressed to that of a high school freshman.
Where and how do I relearn what I've forgotten? I've lost my job because of this.
4 posts and 2 images omitted. Click Reply to view.
Barnaby Fizzletetch - Sat, 02 May 2015 19:18:23 EST ID:Hj/F401x No.14716 Ignore Report Quick Reply
I've been in the exact same situation. Didn't like math in HS, didn't do it for years afterward. When I started taking classes again, I got owned hard.
Fast forward to the day before yesterday and I feel like I did pretty good on the back-to-back midterms I took on Fourier analysis + linear ODEs and algorithms (which is proof-heavy).

The same boiling water that softens the potato hardens the egg.
Martin Dribberdark - Sat, 09 May 2015 01:52:04 EST ID:YlDX0MWs No.14727 Ignore Report Quick Reply
My memory has always been shit, but it turned out to work in my favor for maths because I couldn't just memorize everything, I ended up having to derive everything, and re-derive it and re-derive it sometimes, until it made sense in an I guess "intuitive" level. Turns out this is a pretty good way of learning math, if a bit "slow".

My advice is to start MORE basic than you think. If I say "learn about fractions" and your reaction is "no that's too easy I want to start higher", I would suggest not to skip it. Spend a little bit actually working problems so you definitely have a very solid foundation. When I tutored calculus, there were students who got all frazzled at when where and how (not to mention why) they could "cancel out" a numerator and denominator, so their learning got held up because somewhere along the way they were like "yeah yeah ok whatever got it"
Basil Giffingford - Mon, 11 May 2015 10:33:10 EST ID:bG7/Mgyv No.14731 Ignore Report Quick Reply
Buy/torrent the book "Basic Mathematics" by Serge Lang. It's highschool and precalc but written from the perspective of a mathematician so you get a rigorous logic and analysis course out of highschool math instead of just being a calculator.

Soo by Nell Gabblewell - Sun, 03 May 2015 14:03:43 EST ID:zDln8d4D No.14718 Ignore Report Reply Quick Reply
File: 1430676223389.jpg -(1186244B / 1.13MB, 2592x1936) Thumbnail displayed, click image for full size. 1186244
denominators dont cancel eachother out ,right? Tf do i do here?
2 posts and 1 images omitted. Click Reply to view.
Sophie Perringchure - Sun, 03 May 2015 20:11:51 EST ID:hudlvJsh No.14721 Ignore Report Quick Reply
Looks right to me
Is the equation supposed to equal something? are you trying to solve for a?
Hamilton Fundlebick - Sun, 03 May 2015 21:18:36 EST ID:zDln8d4D No.14722 Ignore Report Quick Reply
Nah I fired it out
I was supposed to multiply the 3s
Hamilton Fundlebick - Sun, 03 May 2015 21:21:48 EST ID:zDln8d4D No.14723 Ignore Report Quick Reply
Yes I believe you do
I got it right

<<Last Pages Next>>
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Report Post
Please be descriptive with report notes,
this helps staff resolve issues quicker.