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



Generating Polynomial by Cedric Mavingwell - Fri, 03 Jun 2016 05:39:35 EST ID:FvfJV3ZM No.15146 Ignore Report Reply Quick Reply
File: 1464946775420.png -(17720B / 17.30KB, 682x185) Thumbnail displayed, click image for full size. 17720
Can anyone shed some light? I thought I just had to substitute powers of t into this equation to get the answer. Am I missing something stupidly obvious? I just can't get to the first line of the answer. http://imgur.com/a/9iWQ1
Hannah Gattingmot - Fri, 03 Jun 2016 11:53:21 EST ID:A2j/BW/W No.15147 Ignore Report Quick Reply
You have to use Taylor expansions. So the first step is to substitute the Taylor expansion for the exponential function. Then you substitute the Taylor expansions for the different powers of the (1-t) terms. Then you group like powers of t. Whoever wrote the solution fucked up by squaring the t inside the parentheses in the third line btw, but they still got the correct result.
Reuben Pittwill - Sat, 04 Jun 2016 04:44:18 EST ID:Ktnbl7MZ No.15148 Ignore Report Quick Reply
>>15147 Thank you mate.
Phoebe Dimmerpuck - Sat, 04 Jun 2016 12:19:38 EST ID:A2j/BW/W No.15149 Ignore Report Quick Reply
No prob.

Probability by Jack Bloffinghood - Sun, 29 May 2016 19:59:52 EST ID:lgvPZ+E8 No.15140 Ignore Report Reply Quick Reply
File: 1464566392861.jpg -(94901B / 92.68KB, 650x434) Thumbnail displayed, click image for full size. 94901
How do you solve these types of problems:

Lets say you have a chicken who, on average, lays 1 egg per day.
After 7 days what is the probability that the chicken will have laid at least n eggs?
Hannah Daffingway - Mon, 30 May 2016 11:31:43 EST ID:lYjTKStM No.15141 Ignore Report Quick Reply
You need to know which probability distribution and it's parameters.
Most examples assume a normal distribution, but even then you need to know it's sigma value.
Of course it would be interesting to solve the differential equation for al sigma values and number of eggs.
Phyllis Soblingnedge - Mon, 30 May 2016 11:33:06 EST ID:A2j/BW/W No.15142 Ignore Report Quick Reply
Eliza Crabblewater - Mon, 30 May 2016 21:48:39 EST ID:lgvPZ+E8 No.15143 Ignore Report Quick Reply
1464659319762.gif -(4642823B / 4.43MB, 500x500) Thumbnail displayed, click image for full size.

I did the calculations using a Poisson distribution and it seems to be working great. The actual average is nice and close the expected average whether I set lambda to 5 or 5000.

pic related

Help explain Principal Component Analysis to a dummy by Oliver Lighthall - Tue, 10 May 2016 12:55:53 EST ID:xd9SEzRh No.15116 Ignore Report Reply Quick Reply
File: 1462899353126.gif -(21904B / 21.39KB, 505x369) Thumbnail displayed, click image for full size. 21904
Hey guys,

I don't know anything about Principal Component Analysis (PCA) but I'd like to learn. Can someone explain to me the PCA algorithm (the algorithm to find the set of PCA vectors) for operating on a 2D set of real data?

Here's my understanding of it so far (feel free to add corrections):
  • First you have to normalize your set of real datapoints because PCA works best on normalized datapoints
  • Then, calculate the mean of the data-set (this is just the flat-average of the various components of the data). So in R2 for instance, this is (x1 + x2 + x3 +...) / (n) and (y1 + y2 + y3 + ...) / (n) for finding the mean X-value and mean Y-value.
  • Next, subtract the mean from the data-points. This centers the data around the origin.
  • Then we begin calculating the variance-covariance matrix, which we're going to use as part of the PCA algorithm
  • Variance of each datapoint is calculated as the "average squared deviation from the mean" which is in this case (the case of already having subtracted the mean from each datapoint) we can simply square each datapoint, then divide by the number of datapoints to find its variance (is this even correct?)
  • Then you have to calculate the covariance (I'm really fuzzy on how to do this part given our initial dataset).
  • Next step is to assemble the variances and covariances that we have calculated into the variance-covariance matrix
  • Then you calculate the eigenvectors and eigenvalues of the variance-covariance matrix. There should be one eigenvector (and each eigenvelue corresponds to one eigenvector) for each dimension in the original dataset (so for 3 dimensional data, you should get 3 eigenvectors).
  • Then for PCA, you sort the eigenvectors by their eigenvalues to find the principal components. The principal components' vectors are the eigenvectors we calculated in the previous step.

Is this right? Can someone explain this to me more simply?

Fuck squares by Isaac Newton - Sat, 07 May 2016 01:20:21 EST ID:HaG6KVm7 No.15112 Ignore Report Reply Quick Reply
File: 1462598421690.png -(847B / 847bytes, 225x225) Thumbnail displayed, click image for full size. 847
I fucking hate squares and shit.

That's why I made apples into circles, they use to be fucking square.

Can Math Ban Me? Fucking squares suck. Soon I will amke sure you can only have round shit. I tried to impress a bitch with a fucking square once, wanna know what the fuck happened? She fucking cried! Cried so loud, even saying, "A trapezoid would have been better!" The nerve of that bitch.

The nerve of /math/. Someone here PROMISED that the bitch would let me stick my shit in her if I gave her a square. You owe me a fixed marriage./ Send nudes of your daughter, I call it even.
George Banderwater - Sat, 07 May 2016 05:04:23 EST ID:A2j/BW/W No.15113 Ignore Report Quick Reply
1462611863500.jpg -(440782B / 430.45KB, 960x540) Thumbnail displayed, click image for full size.
You're a square!

What type of math are you studying? by Isabella Habblefield - Sun, 14 Feb 2016 19:31:46 EST ID:Dk8yywxc No.15046 Ignore Report Reply Quick Reply
File: 1455496306932.jpg -(396464B / 387.17KB, 2480x3508) Thumbnail displayed, click image for full size. 396464
Right now I'm studying large cardinals in set theory and trying to learn more about algebraic topology. A good place to start with topology is the "Topology" by Munkres, and if you have a strong set-theoretic back ground I recommend "The Higher Infinite" by Kanamori for learning about large cardinals. The fact that the existence of a large enough number can be equivalent to something that has nothing to do with cardinals at face value still fascinates me. Here's an interesting chart that shows how we can assume the existence of large enough cardinals right up to contradiction.

What parts of math are you interested in or studying? Why? What are some resources that you recommend for others to get into it?
1 posts omitted. Click Reply to view.
Hugh Drubberforth - Thu, 31 Mar 2016 20:52:08 EST ID:fIwfJdEz No.15078 Ignore Report Quick Reply
I'm working through abstract algebra. I've got an engineering degree, but the math we learn there is much more pragmatic, model-oriented, and number-focused. Whereas math like this, in and of itself, is a bit like a model. For example I personally conceptualize mappings as a sort of data-typing, that's just where it rests in my mind, but I know that it is a more general concept than that-- allowing quotient sets and such has sort of blown my mind in this regard.

I'm trying desperately to cling on to Allan Clark's Abstract Algebra book, which I've been told is really not for beginners. I can see that, but I can fill in the gaps with stuff on the internet. I spend a lot more time puzzling about this book than with other intro texts. Fiddling with the numbers, and trying hard to convince myself of things, and solve problems with my own reasoning, instead of regurgitating the examples.

It's pretty fuckin' rough so far, especially since the only work I have with formal logic/sets is a brief introduction in engineering statistics, and in "severely boiled the fuck down" discrete math 301. And that was about 10 years ago, so yeah. But I'm trying, and I can usually understand the proofs others arrive at, if not nearly arrive at them myself. I'm probably wasting my time, but I like the puzzles.
Hannah Dinningtitch - Sat, 09 Apr 2016 18:19:26 EST ID:LR+0MgV1 No.15085 Ignore Report Quick Reply
1460240366149.png -(258528B / 252.47KB, 1920x1080) Thumbnail displayed, click image for full size.
I like to study computational theory, so things like lambda calculus and functional programming langues. It's a really nice mix between pure mathematics and computer science.
Hannah Sollernodge - Fri, 22 Apr 2016 12:45:25 EST ID:WD6PkLOh No.15099 Ignore Report Quick Reply
Well I studied Pharmacology, but I've been re-reading some of my Advanced Higher (stuff you do in the last year of secondary education) maths and reading a couple of books aimed at the average person. Are there any college-level maths topics which are particularly cool or satisfying? I loved that feeling of it all coming together when I relearned partial fractions, proofs, calculus (before you get trig functions involved and it all goes to shit). Anything in the same vein I could learn now? I have no problem putting in hours of work, and I usually don't have a problem grasping new mathematical concepts

i can't do math by Lillian Saffingbanks - Fri, 15 Apr 2016 18:21:07 EST ID:YoFLr1Ak No.15092 Ignore Report Reply Quick Reply
File: 1460758867923.jpg -(272402B / 266.02KB, 1300x924) Thumbnail displayed, click image for full size. 272402
im 25 and i can barely understand algebra, im a high school drop out.

what am i going to do i need to go back to college but if i don't pass their math test i am not allowed in....what shall i do?
Walter Murddock - Fri, 15 Apr 2016 19:06:10 EST ID:A2j/BW/W No.15093 Ignore Report Quick Reply

You can try teaching yourself math using the above link or hire a tutor.
Samuel Drimbletedging - Wed, 20 Apr 2016 22:12:08 EST ID:RHLOntyV No.15097 Ignore Report Quick Reply
If you're going to community college you should be fine, many have pre-algebra remedial classes you can take.
Hannah Sollernodge - Fri, 22 Apr 2016 12:37:03 EST ID:WD6PkLOh No.15098 Ignore Report Quick Reply
I recommend Khan academy very highly. I'm an amateur but I really love maths, and I love to share it with my girlfriend (who never did well at school), but sometimes we just get stuck on something and I've explained it every way I can to her.
Without fail, we watch the KA video and she understands in 5 minutes

PDEs by Jenny Cabblehall - Fri, 15 Apr 2016 11:45:52 EST ID:FXvLlomd No.15090 Ignore Report Reply Quick Reply
File: 1460735152003.png -(363794B / 355.27KB, 1920x1080) Thumbnail displayed, click image for full size. 363794
guys help

Why are we assuming h(x, t) to be a fourier sine series instead of using the whole fourier series? It's certainly easier for decomposing the equation into an ordinary differential equation but what if it can't be represented by sine alone?

Also, why do we assume that the function in the integral from 0 to L of h(x, t)*sin(n*pi*x/L)dx is an even function? If it's an odd function, then the integral converges to zero and then what do you do?
Jenny Cabblehall - Fri, 15 Apr 2016 16:19:42 EST ID:FXvLlomd No.15091 Ignore Report Quick Reply
Ok so i understand now why h(x,,t) is a fourier sine series, but it seems like this method only works for when h(x,t)'s x part is an odd function, otherwise the integral either becomes zero or the function has a sine AND cosine series representation. If this is the case, this method doesn't work, right?

I don't believe in Math by A Wizard - Thu, 07 Jan 2016 00:39:32 EST ID:+mzdzIig No.15015 Ignore Report Reply Quick Reply
File: 1452145172589.jpg -(8086B / 7.90KB, 252x200) Thumbnail displayed, click image for full size. 8086
how come you can't put any symbol in any order and make the claim that it is what you say it is?

>its a conspiracy
5 posts omitted. Click Reply to view.
Molly Clayfield - Wed, 09 Mar 2016 02:29:30 EST ID:FwRHmRUr No.15067 Ignore Report Quick Reply
god invented math to troll you fucks, checkmate
Molly Grandhood - Fri, 01 Apr 2016 12:42:21 EST ID:pPznVtZ8 No.15080 Ignore Report Quick Reply
1459528941946.jpg -(48015B / 46.89KB, 720x540) Thumbnail displayed, click image for full size.
you can
it's called SSDoCt0rTo
Albert Fonderchork - Sun, 10 Apr 2016 14:19:31 EST ID:BI41XwUF No.15087 Ignore Report Quick Reply
1460312371052.jpg -(59771B / 58.37KB, 600x799) Thumbnail displayed, click image for full size.
Apart from the most elementary mathematics, like arithmetic or high school algebra, the symbols, formulas and words of mathematics have no meaning at all. The entire structure of pure mathematics is a monstrous swindle, simply a game, a reckless prank. You may well ask: "Are there no renegades to reveal the truth?" Yes, of course. But the facts are so incredible that no one takes them seriously. So the secret is in no danger.

How to become an amateur mathematician? Along with book recommendations. by Shitting Crittingworth - Sat, 20 Sep 2014 20:13:43 EST ID:aC7pKNlN No.14371 Ignore Report Reply Quick Reply
File: 1411258423261.jpg -(66533B / 64.97KB, 960x402) Thumbnail displayed, click image for full size. 66533
I have How to Solve it by Poyla, The Mathematical Experience , CRC Concise Encyclopedia of Mathematics, and Mathematical thought from Ancient to Modern Times.

Are there any good general mathematics books out there? I'm not too interested right now in becoming a mathematician that focuses on a very specific field.
2 posts and 1 images omitted. Click Reply to view.
David Cebberwig - Mon, 22 Sep 2014 02:30:49 EST ID:LZtslkSN No.14374 Ignore Report Quick Reply
1411367449379.png -(11346B / 11.08KB, 152x79) Thumbnail displayed, click image for full size.
I am also an amateur mathematician. Pic related.
Cornelius Pendletedge - Mon, 22 Sep 2014 19:18:14 EST ID:m9zbwPJj No.14377 Ignore Report Quick Reply
1411427894409.jpg -(1493488B / 1.42MB, 1920x1200) Thumbnail displayed, click image for full size.

>Amateur as opposed to professional,
>I just want to learn math as a hobby.

That's not very helpful. Yes, I figured that by "amateur", part of what you meant is that you didn't expect to get paid for it.

Do you just want to amuse yourself? With easy problems? Hard problems? Do you want to publish?

Keep in mind that Pierre de Fermat was an amateur mathematician.


>and my background is a a few college algebra/Pre-calculus classes.
Comment too long. Click here to view the full text.
Shit Brookford - Thu, 10 Mar 2016 22:12:27 EST ID:Owidv0kC No.15068 Ignore Report Quick Reply
1457665947160.jpg -(542974B / 530.25KB, 921x1300) Thumbnail displayed, click image for full size.
Start here => "Polya - How to Solve It"

So what would you do if... by Wesley Fonkinhood - Wed, 27 Jan 2016 06:47:23 EST ID:4TF5vVu6 No.15033 Ignore Report Reply Quick Reply
File: 1453895243617.jpg -(132162B / 129.06KB, 960x671) Thumbnail displayed, click image for full size. 132162
You had actually figured out how to quantify stupidity?

I don't mean an IQ test, I mean if you had spatial sequence synaesthesia and you could literally see the difference between stupid people and smart people, as well as translate it into a quantity and develop a comprehensive test for deriving exactly how fucking stupid someone was?

I am worried about either having my discovery stolen or being murdered by some letter soup agent. I feel like Ignaz Semmelweis. This is probably the last place I will look for help. Pic only slightly related in a very abstract sense.
1 posts and 1 images omitted. Click Reply to view.
Fuck Craffingshit - Thu, 18 Feb 2016 15:44:54 EST ID:lPEtDIQb No.15049 Ignore Report Quick Reply
Gotta say, this sounds like utter nonsense (extraordinary claims need extraordinary evidence). If you think your methods are valid and you're worried about having your discovery stolen, then publish in a (reputable) journal. That's typically how this sort of thing is done.

If you are worried about alphabet soup agents, I'm afraid there's precious little you can do about that.
Simon Druddleson - Sat, 20 Feb 2016 23:30:35 EST ID:hlEla/1i No.15050 Ignore Report Quick Reply
it's called psychosis.
Molly Clayfield - Wed, 09 Mar 2016 02:18:38 EST ID:FwRHmRUr No.15066 Ignore Report Quick Reply
ordinary claims need ordinary evidence

Not certain synesthesia is anything more than 'normal' active imagination, some being more active than others' (from a lack of beatings, realistically.)

There's something similar where you can read someone's face and judge pretty accurately their experience before they speak, but there's usually other more obvious give-aways.

<<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.