This tag is for questions that are asking for online resources in mathematics (references, dictionaries, encyclopaedic collections, online tools, videos an lectures, etc), or asking about the mathematics behind tools and technology found on the internet.

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3
votes
1answer
2k views

Where can I calculate the exponential of a matrix online?

Where can I exponentiate a $3\times 3$ matrix like $\left[\begin{array}{ccc} 0 & 1 & 0\\ 1 & 0 & 0\\ 0 & 0 & 0 \end{array}\right]$ online? Is there some website where this ...
12
votes
1answer
763 views

Overview of basic facts about Cauchy functional equation

The Cauchy functional equation asks about functions $f \colon \mathbb R \to \mathbb R$ such that $$f(x+y)=f(x)+f(y).$$ It is a very well-known functional equation, which appears in various areas of ...
1
vote
2answers
200 views

Study regimen for discrete mathematics? - Lack high-school maths…

I have just gotten into college, and will be studying mathematics from next semester. (this course) Unfortunately I did not study mathematics for the last 2-3 years of high-school mathematics. What ...
3
votes
0answers
83 views

Online Model Theory Classes

Since "model theory" is kind of too general naming, I have encountered with lots of irrelevant results (like mathematical modelling etc.) when I searched for some videos on the special mathematical ...
-2
votes
2answers
338 views

Missing Exercises in Elementary Number Theory by Underwood Dudley.

I'm a beginner in math and I just started studying Elementary Number Theory by Dudley. So far I'm impressed, but I've noticed that the book does not include all the solutions to the exercises they ...
5
votes
4answers
176 views

Math school online?

As a hobbyist programmer with little to no math skills (no science skills either, thank you religious schools) I am finding math encroaching on my life more and more often. I have always laughed and ...
4
votes
2answers
94 views

Looking for a source of an infinite trigonometric summation and other such examples.

Question: If $x \neq 0$, then prove that $\displaystyle \sum_{n=1}^{\infty}\dfrac1{2^n} \tan\left(\dfrac{x}{2^n}\right) = \dfrac1{x} - \cot x.$ My answer: I proved this result by using the ...
3
votes
1answer
778 views

Differential Geometry Video Lectures

I know there's a similar question here, however since what I found there wasn't what I was looking for I thought on creating a new question. I'm studying Differential Geometry through Spivak's book "A ...
8
votes
2answers
280 views

What kind of math topics exist?

What kind of math topics exist? The question says everything I want to know, but for more details: I enjoy studying mathematics but the problem is that I can't find any information with a summary ...
0
votes
1answer
125 views

A matrix has a real logarithm if it has a positive spectrum.

The title is a proposition I read in my notes that's left with no proof. Where can I read one?
0
votes
1answer
170 views

Dynamical Systems. Bendixson's and Dulac-Bendixson's theorems.

I am looking for a place to read the proofs of Bendixsons and Dulac-Bendixsons theorems. Namely let D be a simply connected set and the following system be defined in D. $$\dot x=P(x,y)$$ $$\dot ...
1
vote
1answer
82 views

Finding equations of lines

I'm sitting an exam soon and have been revising for a while but I sometimes get stuck with questions that I know are simple but still have no idea about how to do them at all! Please explain to me how ...
1
vote
0answers
36 views

Order of operations

Looking for a source that lists every possible proper order of operations. The reason for this is that I made a mistake with fractional exponents, I don't want to make this mistake again.
0
votes
1answer
104 views

Probability Distribution Of A Linear Combination

I have scoured my textbook for the concept alluded to in the title of this thread; however, my textbook has failed, in that it provides no such information. Does anyone know of some resources for ...
3
votes
2answers
111 views

What are good resources to learn Mathematics for a working professional?

I have been out of school and working for 17 years now. I cannot remember anything I learned about trigonometry, algebra or geometry (which I think is as far as it went in those days) but I do find ...
8
votes
4answers
1k views

Overview of basic results about images and preimages

Are there some good overviews of basic facts about images and inverse images of sets under functions?
2
votes
1answer
116 views

Steiner symmetrization preserves area?

I just finished reading (and understanding) Steiner's proof of the isoperimetric inequality. His proof (which is sadly incomplete) seems to rely much on the fact Steiner symmetrization preserves area ...
1
vote
0answers
78 views

Resources to learn more about universality?

I'm fascinated by what I think is called Universality in mathematics. What I mean by this is systems with simple rules displaying very complex behaviours in aggregate. Conway's game of life, Wolfram's ...
13
votes
2answers
493 views

How to start a math blog?

I'd like to start a blog where i can write mathematics related notes. The intended audience is mainly myself, but i don't mind it being available for public viewing. I'd like to keep setting up, ...
1
vote
3answers
652 views

What are the best websites for learning math? [closed]

What I known: this site mathoverflow khanacademy Are there any other website for learning math? Which one do you think is the best?
8
votes
1answer
145 views

Classification of all 28 Exotic 7-Spheres

In http://en.wikipedia.org/wiki/Exotic_sphere#Explicit_examples_of_exotic_spheres Wikipedia says "As shown by Egbert Brieskorn (1966, 1966b) (see also (Hirzebruch & Mayer 1968)) the intersection ...
20
votes
2answers
513 views

Do free online collaborative solution manuals exist?

I'm not a mathematician by training and a rarely come in contact with mathematicians. For this reason I find solution manuals to be incredibly useful - reading them allows me to see how experienced ...
2
votes
2answers
92 views

Mathematically-based online games

I am looking for online games or puzzles which have a mathematical flavor and are suitable for general audiences. A classical example is the online version of Set Card Game. Or this game that has some ...
1
vote
3answers
915 views

Resources for self-study of general topology

Could you point me to good resources for self-study of general topology. I want to learn the basics and how to prove theorems about structures like polyhedra by myself.
113
votes
6answers
4k views

Best Sets of Lecture Notes and Articles

Let me start by apologizing if there is another thread on math.se that subsumes this. I was updating my answer to the question here during which I made the claim that "I spend a lot of time sifting ...
1
vote
0answers
17 views

Skein trees resource

Is there a resource where a collection of Skein trees for the Conway polynomials of knots have been presented? Thanks
2
votes
1answer
494 views

AP BC Calculus Resources

I am studying for the AP BC Calculus Exam and I know about the free response questions from AP Central, and the Multiple Choice Collection. I was wondering if anyone here knew of where to obtain more ...
17
votes
6answers
2k views

How to go from beginner to expert in mathematics?

I'm particularly interested in knowing the order of subjects one should study to become good in mathematics. In my not so great knowledge of the subject I would say that the best place to start could ...
7
votes
1answer
244 views

Learning linear algebra and probability by a challenge each day

For a few weeks, I spend some time to solve a question from Project Euler each day. I liked it and noticed that it makes me motivated. I wonder if there exists such a site with challenging questions ...
2
votes
1answer
57 views

Find data to perform regression analysis

I'm trying to find some data (two continuous variables that I believe are correlated) online for which I can perform a regression anaylsis, my assignment sheet says: The data may be found anywhere ...
3
votes
2answers
100 views

Useful faculty sites that provide explanations of mathematical ideas

I'm looking for resourses on undergraduate mathematics, explaining ideas behind well-known proofs, etc. What are some other sites like T. Tao's blog or T. Gowers'? I.e. ...
1
vote
0answers
53 views

Regression with multiple line types from set of points

Given a set of points, I'm looking to find the best possible line (within reason) to fit to these points. These points won't be from real data, so they could form any sort of curve or line. So, I ...
9
votes
3answers
222 views

Links to Online Videos of Good-Quality Lectures by Mathematicians

I am not trying to do anything new here, but I would like to start an activity that has been going on at Math Overflow. Hopefully, people here at the Math StackExchange can also enjoy the good stuff. ...
3
votes
2answers
253 views

Differential Forms Help

I have a background in Analysis, specifically with Baby Rudin. However, as many people note, Rudin does not do a very good job discussing differential forms. Could someone please refer me to an ...
3
votes
2answers
200 views

Can anybody recommend a website or other type of resource which contains real Analysis-type questions and their solutions?

In a recent post I asked about an epsilon delta proof for an Analysis question. Before posting it I searched for similar questions and their proofs on google but all I found were computational style ...
9
votes
2answers
542 views

What's up with Plouffe's inverter? Is there an alternative?

For quite some time now (at least a year), whenever I tried to use Plouffe's inverter, the request timed out, but there's no indication either on the site itself or on the Web that it's out of service ...
0
votes
1answer
225 views

Linear programming / linear optimization with R? [closed]

Any good books or websites that teach linear programming / linear optimization with R? Thanks. Edit (Jan 6, 2013): The following R code is an example by using the "lpSolve" package. ...
2
votes
1answer
566 views

Linear programming / linear optimization video lectures?

Is there a good set of linear programming / linear optimization video lectures somewhere? I found "Linear programming and Extensions" by Prof. Prabha Sharma, Department of Mathematics and ...
4
votes
2answers
85 views

Review papers in mathematical analysis

In theoretical physics, there are resources on the web that contain the most cited review papers in each field that are very valuable for some one doing research. Is the same true in mathematical ...
1
vote
1answer
70 views

How to test a formula online?

I have an equation I have devised, it is: $$\frac{H+O}{25}+\frac{D}{12970}+\frac{E}{363}+110 = X$$ The equation doesn't matter, I just posted it as an example. I need to be able to plug in values ...
2
votes
0answers
59 views

What is a good resource for functional derivatives and functional determinants?

What is a good resource for functional derivatives, functional determinants, etc.? What is the branch of mathematics dealing with those things? It is not in my functional analysis book. What is a ...
1
vote
1answer
160 views

Good substitutes for Ross's book on Probability Models

I was wondering if there are any FREE good alternatives to Sheldon Ross's Probability Models which are more succinct? Are there any free online resources (websites/PDFs/course notes) which cover more ...
2
votes
2answers
645 views

Ebook resources for math learning (10th-12th grade)

After searching the site, i found some questions like mine, but none fits my case. I am a 11th grade student, and i have an ebook reader(kindle). I would like to know where can i find(free) content ...
2
votes
2answers
210 views

Resources for IMO

I am seeking an online resource or any book where I can find the questions of International Mathematical Olympiad questions chapter wise eg Number Theory problems grouped together. Like this site ...
6
votes
0answers
287 views

Resource: Group Theory

There is a website providing recent thesis in finite geometry. Is there any website with collection of recent thesis on (finite) group theory. I want to see the Ph.D. thesis of Raymond T. Shepherd, ...
6
votes
1answer
170 views

What is a good communication platform, which supports something like TeX-code?

I moved away and am now planning to communicate with a friend over the internet and talk about mathematical subjects (e.g. via Skype). However the text blocks like "\int_G\omega..." in a chat window ...
1
vote
0answers
68 views

Is there a website dedicated to the application of Category Theory to different branches of Mathematics?

For example, if I wanted to know what the product/coproduct is in a certain category, I could find it on that site. I commonly come across websites (such as wikipedia) that give a few examples of ...
1
vote
2answers
174 views

Any video lectures on conventional analytical geometry?

Hi this question is kind of a natural offshoot to this question My topic covers very conventional topics like : Cartesian and Polar Coordinates in 3 Dim, second Degree eqns in 3 vars, reduction ...
1
vote
0answers
871 views

IGCSE/GCSE mathematics worksheet and resources

I take mathematics for Cambdridge IGCSE students, Syllabus code 0580, http://www.cie.org.uk/docs/dynamic/41073.pdf , Please i want to know about resources available to revise the math topics, and if ...
1
vote
1answer
345 views

Source of probably-the-most-simplest-math-trick

I am just 18, completely naive and new to the world of maths. I have made a few math tricks based on this trick (or tricks of this format - with the exact calculations and steps involved): TRICK: ...