# Tagged Questions

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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### 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 ...
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### 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?
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### Overview of basic results on cardinal arithmetic

Are there some good overviews of basic formulas about addition, multiplication and exponentiation of cardinals (preferably available online)?
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### Exploring $\sum_{n=0}^\infty \frac{n^p}{n!} = B_pe$, particularly $p = 2$.

I was exploring the fact that $$\sum_{n=0}^\infty \frac{n^p}{n!} = B_pe,$$ where $B_n$ is the $n$th Bell number. I found this result by exploring the series on wolframalpha and looking up the ...
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### 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 ...
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### Online resources for learning Mathematics [closed]

Not sure if this is the place for it, but there are similar posts for podcasts and blogs, so I'll post this one. I'd be interested in seeing a list of online resources for mathematics learning. As ...
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### Online tool for making graphs (vertices and edges)?

Anyone know of an online tool available for making graphs (as in graph theory - consisting of edges and vertices)? I have about 36 vertices and even more edges that I wish to draw. (why do I have so ...
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### Are mathematical articles on Wikipedia reliable?

I know that Wikipedia gets a bad rap, and it seems like some teachers of mine have nothing better to do in class than harp on about the Great Academic Pastime of calling Wikipedia untrustworthy, but ...
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### Known bounds and values for Ramsey Numbers

Is there a good online reference that lists known bounds on Ramsey numbers (and is relatively up to date)? The wikipedia page only has numbers for $R_2(n,m)$. I am specifically interested in known ...
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### phd qualifying exams

Where can I find phd qualifying exams questions.Is there any website that keeps a collection of such problems? I need it for doing some revision of the basic topics. I know of a book but that do not ...
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### Chatting about mathematics (with real-time LaTeX rendering)

Do you know about some tools which can be used for online chat about mathematics? In particular, I am interested in software which would be able to render LaTeX formulas. (Since LaTeX is probably the ...
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### Introductory text for lattice theory

What would be your recommendation for the text which could be useful for someone starting with lattice theory? Suggestion for both books and online materials/lecture notes are welcome. This was ...
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### 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 ...
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### List of Interesting Math Blogs

I have the one or other interesting Math blog in my feedreader that I follow. It would be interesting to compile a list of Math blogs that are interesting to read, and do not require research-level ...
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### List of interesting math podcasts?

mathfactor is one I listen to. Does anyone else have a recommendation?
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### Is there a good “bridge” between high school math and the more advanced topics?

I love math and would like to know more of it. However, whenever I try to pick up a book on what I consider to be "advanced" mathematical topics, I often have a hard time understanding some of the ...
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### Resources/Books for Discrete Mathematics

I am going to a Computer Science Course in University next year. I heard that Discrete Mathematics is whats required for Comp Sci so, I am looking for resources/books that I can read to get started ...
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### Generating functions for combinatorics

I have no formal education in generating functions, but, based on another question, I have seen that they can be powerful for combinatorics. Are there a few general principles for using generating ...
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### Free Graph Theory Resources

What freely available graph theory resources are there on the web? In particular, I am interested in books and lecture notes containing topics such as trees, connectivity, planar graphs, the ...
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### A good reference to begin analytic number theory

I know a little bit about basic number theory, much about algebra/analysis, I've read most of Niven & Zuckerman's "Introduction to the theory of numbers" (first 5 chapters), but nothing about ...
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### What does Khan Academy have to offer? Depth? Rigor?

Khan Academy - http://www.khanacademy.org/ - is often cited as a great online resource for learning mathematics and other subjects. I have heard many good things about this website and was wondering ...
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### Books or site/guides about calculations by hand and mental tricks?

Any ideas about books I can get, from amazon? I need to get really good at mental math and math by hand because I'm taking an exam soon and that without a calculator. Thanks.
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### Exercises on Galois Theory

I need a source for exercises on classical Galois Theory, or to be more specific, Galois extensions of finite fields and the rationals as well as applications (solvability by radicals, for example). ...
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### How to write special set notation by hand?

Does anyone know a good resource (preferably pictures) that illustrates a conventional way to write the special sets symbols, i.e. $\mathbb{N,Z,Q,R,C}$ etc., by hand?
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### 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 ...
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### Subtraction of numbers with arbitrary bases [duplicate]

Possible Duplicate: How to do +, -, *, / with number in a base b? I am reading research papers in the category of recreational mathematics on the topic of numbers similar to Kaprekar number. ...
14k views

### Learning Lambda Calculus

What are some good online/free resources (tutorials, guides, exercises, and the like) for learning Lambda Calculus? Specifically, I am interested in the following areas: Untyped lambda calculus ...
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### Qual question archives?

Qual questions seem like a great way to study for a new topic, since they usually test slightly deeper understanding than typical questions in a textbook. Princeton has this great archive of questions ...
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### 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 ...
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### How to search the internet for strings that consist mostly of math notation?

Is there a trick to search the internet for math notation? For example what if I want to search the internet for "X / ~" ? The default google search is useless for this and for similar searches ...
899 views

### Useful mathematical fora

I want to ask about various mathematical fora and discussion boards available online. I think it might be useful to have such a list here at Math.SE. If I may suggest, it could be useful to keep one ...
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### How do I find partners for study?

I want to find partners to study some post-graduate topics together online (because I'm pretty much out of steam as far as self-study goes, and I have problems finding a decent grad school). Are there ...
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### Are there any good Discrete Mathematics video online?

I want to learn discrete mathematics by reading book by myself but I find sometime it's very hard to understand what author trying to say. I want to know, are there any good online video that teach ...
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### How to google search mathematical notions and expressions?

It is usually not difficult to google search mathematical notions; for example, one can search (with quotation marks) the term "brunnian braid" and find the definition and other related materials. ...
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### Video lectures for Commutative Algebra

Are there any good video lectures for learning commutative algebra at level of Atiyah-Macdonald?
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### 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 ...
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### Which textbook of differential geometry will introduce conformal transformation?

Which textbook of differerntial geometry will have these formulas about conformal transformation? $$\tilde g_{ij} = e^{2\varphi}g_{ij}$$ \tilde \Gamma^k{}_{ij} = \Gamma^k{}_{ij}+ \delta^k_i\...
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### Online classes/books in multivariable calculus?

So does anyone know of any good online courses in multivariable calculus? (Or in a possible alternative leap of curriculum, if said path has proven to be better/moar interesting.) I'm coming straight ...
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### Stochastic Processes Solution manuals.

Does anyone have a link or a pdf stash of solution manuals for stochastic processes ebooks? I am doing a self-study on this course and I can't seem to find any solution manual online to cross-check ...
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### 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 ...
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### Which discussion board is good for homework questions? [closed]

I'm a CompSci university student and i want some help for my math questions. Therefore i am looking for a good discussion board for math homework questions. I don't know any (good), because I come ...
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### Infinite Series Manipulations

Is there any comprehensive list (books, online, ...) of rules for manipulating infinite series (partial sums) to find convergence of a sum? Often authors use some "trick" to compute an infinite series....
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### 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 ...
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### 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 ...
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### Is there a 'Mathematics wiki' analogous to 'String theory wiki'?

I came across this site and am wondering if there is a similar page for Mathematics or its sub-areas. Would be very nice if there is one such site which provides 'canonical' references for each sub ...
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### Calculus Review On The Web

Can anyone recommend a calculus review site on the web? I just signed up for MITx's on-line 6.002 and while there will be remedial differential equation help offered in the first half of the course, ...
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### Statistics resources with examples for a C.S. student

I'm a computer science student and is fairly familiar with basic probability (calculating the probability of a event occurring, pmfs and pdfs) but I find it very difficult to grasp the concepts of ...