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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1
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1answer
41 views

I need a good online statistical significance calculator

What I'm looking for is pretty simple but after half an hour on Google I still haven't found anything. What I need is a reliable statistical significance calculator to compare two samples. For ...
1
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0answers
58 views

Instructive video content for High School kids?

I need some math Youtube channels (or any other visual media, movies maybe...) that I can recommend to High School students, not solely as a method of learning math but more to illustrate the beauty ...
0
votes
0answers
71 views

Matrix gallery resource

Does anyone know of a comprehensive list of matrix types (including a definition of each type)? I am looking for something like this. Importantly, it would be useful if there was a simple example of ...
3
votes
1answer
549 views

Online Finite Field Calculator

I need to find an online Finite Field calculator with the following operations: Inverse SqrRoot Mult Div I have found one a couple of days ago but lost the url, and cannot find it now. Any ...
6
votes
1answer
168 views

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}+ ...
0
votes
0answers
13 views

How to simultaneously search multiple finite sequences in OEIS?

Suppose I have several finite sequences and I want to know if they show up in a family of sequences or any one particular sequence or on rows of an array on OEIS; is there such a search option.
1
vote
1answer
51 views

Diagrams of links in public domain or licensed under Creative Commons

I'm writing a set of notes on topology that I'd like to share under the Creative Commons. Does anyone know where to find diagrams for links (not the Borromean link, I have that already) that are ...
96
votes
10answers
7k views

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 ...
0
votes
3answers
183 views

Elementary linear algebra book

I read and enjoy Spivak calculus book; I was wondering if there is a similar book (in terms of problems, rigor, etc) for elementary linear algebra?
5
votes
1answer
262 views

Mathematical YouTube channels?

So I'm wondering if anybody knows any good math/science related YouTube channels? As for the math channels, I'm currently subscribed to Numberphile, and that is about it. I know few other channels, ...
0
votes
5answers
173 views

where can I take an online Second course in Linear Algebra or second abstract algebra?

Hi i am looking for an online/independent study Second course in Linear Algebra or abstract algebra I and II? Can you point me in the right direction. I need college credit. I need help ASAP Even a ...
1
vote
0answers
24 views

Online tools for plotting and deriving formulas from set of data?

I have a matrix of 20x3 decimal values. I would like to have them in a graph, with one plot for each of the three y values. I would also like approximated formulas for each of the three. Are there any ...
1
vote
1answer
100 views

Rotman, Corollary 5.45.

Rotman's book on group theory includes the following proposition, as a corollary of the fact that $\Bbb Z_{2^n}^\times \simeq C_2\times C_{2^{n-2}}$ Corollary 5.45 Let $G$ be a group containing ...
3
votes
1answer
56 views

Online tools for generating the NULL SPACE of the matrix over Finite Field of size 2

Is there any online tool where I just enter the values in (0,1) Finite Field of size 2 and it's give me the NULL SPACE matrix ? I have 25x25 , 36x36 , 25x36 , 36x25 matrix. Below is my 25 x 25 ...
4
votes
2answers
44 views

Where to look for “standard” ODE solutions?

I remember one day having stumbled upon a nice online resource where one could look for solutions to very general ODEs (or at least the literature names thereof), but unfortunately I forgot its ...
29
votes
10answers
3k views

How to be a successful math undergraduate student?

I am an undergratuate student in my first year of combined bachelor of electrical engineering and bachelor of mathematics. For my mathematics degree, this year I am supposed to take two math courses ...
3
votes
3answers
464 views

Online lectures for a first course in mathematical logic

I have a friend who is interested in learning math. I suggested that he learns mathematical logic. He has never learnt mathematical logic before, however I believe he has all the necessary ...
0
votes
0answers
44 views

Calculus book with different definition of derivative

I am looking for a calculus book which defines derivative as a linear approximation and not as a rate of change. Then it generalizes this notion to derivatives from $\mathbb{R^n}$ to $\mathbb{R}^m$. ...
1
vote
0answers
49 views

Getting started with contact bundles

I'm currently reading William Burke's book Applied Differential Geometry and he uses a lot in the development of Lagrangian Mechanics the notion of a Contact Bundle. He does explain intuitively what ...
2
votes
1answer
128 views

Need to learn wavelet, suggest steps and resources

I am looking for a good introduction to wavelets and wavelet transforms. that covers the following: Basics Vector Spaces – Properties– Dot Product – Basis – Dimension, Orthogonality and ...
2
votes
3answers
82 views

How to reduce predicate logic into propositional logic?

I read that predicate logic reduces into propositional logic. However, I couldn't find anything online that explains the process. Do you know where I could find an explanation? Thank you.
4
votes
0answers
32 views

Calculate with sequences from OEIS

Is there any easy way to do calculations with sequences from OEIS online? For example I would like to input something like: (A007620(n+1) / 2 ) + A000027(n) and ...
3
votes
2answers
58 views

Proof that diagonally dominant matrices are regular - Reference request

I know that it is easy to proof that diagonally dominant matrices are regular (non-singular) by the gershgorin circle theorem. But the theorem that diagonally dominant matrices are regular was ...
2
votes
0answers
99 views

Exercises or courses to improve logical rigor and reasoning skills

There is plenty of math that is beautiful without needing much explanation of theory, such as fractals, geometric patterns and the Game of Life, that may interest beginners in mathematics. However, if ...
4
votes
3answers
121 views

What's a good resource to learn about the simply typed lambda calculus?

I've read An Introduction to Functional Programming Through Lambda Calculus by Greg Michaelson, and found it to be a very good resource to learn about the untyped lambda calculus. However, I want to ...
2
votes
0answers
42 views

Is there a source that explains or defines terms like Theorem, Proposition, Lemma and Corollary?

I will write the German names of the following English terms in brackets as it is important that I use the correct terms. This is a question about terms and I'm not completely sure if I've ...
1
vote
1answer
104 views

Good ODE Books That Explain How Solution Methods Came To Be and Their Justifications

As part of the mathematics program offered at my college, I took an introductory ODE course a few semesters back. This was the one math course in my entire college career that I was totally lost in. ...
6
votes
1answer
289 views

Animations or Pictures of Group of Rigid Motions (or Rotations) of the Cube

Consider a cube that exactly fills a certain cubical box. As in Examples 8.7 and 8.10, the ways in which the cube can be placed into the box corresponds to a certain group of permutations of the ...
18
votes
1answer
585 views

“Bad” Mathematics in Movies

There's a website and a companion book to it about bad physics in movies, called "Insultingly Stupid Movie Physics". Similar issues may exist about mathematics: What are the differences between ...
3
votes
1answer
822 views

Tool to extrapolate data

I have daily data. 6.5315 4.9240 4.3253 3.9703 3.5932 3.2923 3.0785 3.4432 2.6213 2.4083 2.2602 2.1614 2.1351 2.0412 It looks like exponential function or ...
5
votes
1answer
50 views

Detailed Visual Introduction to Complex Numbers with Problems and Solutions

I'm aware of http://tutorial.math.lamar.edu/Extras/ComplexPrimer/ComplexNumbers.aspx. It's very detailed and helpful but I'm looking for something with more pictures. It also doesn't have enough ...
6
votes
0answers
467 views

Solution manual to Larson's “Problem Solving through Problems”

I am working through Larson's "Problem Solving through Problems" (http://math.la.asu.edu/~ifulman/mat194/problem-solving.pdf) but many of the problems have neither solutions nor sources included. Does ...
1
vote
0answers
19 views

More contemporary resource for Greenberg

Is there a more modern textbook than Greenberg's forms in many variables, or a set of notes, that summarizes the developments about $C_i$ fields? Is there such a thing as $C_i$ field where $i$ is not ...
0
votes
1answer
35 views

Resources on Stone-Čech compactification

I'm currently studying R.C. Walker's book on the subject which seems quite extensive and detailed. I've also been skimming through Hindman and Strauss's book Algebra in the Stone-Čech ...
3
votes
1answer
113 views

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 ...
2
votes
0answers
73 views

A Proof of Bruns' Theorem

I am looking for a proof of Bruns' Theorem. Theorem: The 10 classical integrals of the three-body problem are the only algebraically independent integrals of this 18-degree-of-freedom system.
0
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1answer
22 views

Absolutely rough planes

What is an absolutely rough plane? Can you give an analytical expression of one? Why cannot a rigid body slide on a rough plane? Why does the point of contact not move in an infinitesimal movement of ...
2
votes
3answers
190 views

Learning times tables?

I have some weird gaps in my learning, I can do lambda calculus and some basic category theory, but I do not know how to do some of the most basic of arithmetic. (I am in my mid 20s) Seeing this gap ...
1
vote
1answer
129 views

Online homework/testing systems?

I have been using Pearson's MyMathLab Global with my Engineering students. I appreciate its convenience, but the students find its inflexibility annoying (if an answer is expected to be 1.5, then the ...
0
votes
1answer
272 views

Competition style mathematics

I'm currently 18 years old and only as of the part year taken a strong interest in maths. I'm working with my school curriculum (UK a-level) and receiving A grades so I am happy with this. However I ...
2
votes
2answers
1k views

MOOCs for college-level discrete math?

Specifically I am looking for short lectures (and quizzes) on specific topics. (like Khan Academy offers) Topics I am learning about include; Intro logic-theory + set-theory Notation, negation, ...
4
votes
1answer
302 views

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 ...
1
vote
1answer
197 views

Producing tree diagrams of formulae and expressions. (software request)

By "tree," let us mean a tree that is finite, ordered and rooted; but not necessarily binary (that is, every node can have an arbitrary number of children). Under the definition, most mathematical ...
1
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0answers
95 views

What is a good source of problem-solving type problems?

I am not looking for contest problems where there is a clever trick or a standard approach, I am looking for more creative and open-ended problems such as this , and I am not looking for questions ...
0
votes
1answer
113 views

A website where I can evaluate a definite integral and also get a step-by-step solution

Does anyone know of a site where I can evaluate a definite integral and also get a step-by-step solution? Help appreciated. Thanks.
10
votes
1answer
373 views

Toddler introductions to higher mathematics

I bought my youngest (now 10 months old) "Introductory Calculus For Infants" by Omi Inouye a while back. It's actually an ABC book about the letter x and how no one ever plays with him until he meets ...
0
votes
1answer
111 views

Any two Poincare’s maps for a periodic phase space are diffeomorphic

My lectures examine in detail Poincare’s map for dynamical systems with a periodic trajectory. They, however, mention only in passing the construction for a dynamical system with a periodic phase ...
1
vote
1answer
49 views

Need a source for the following result: From $v \in H^1$ and $f$ Lipschitz it follows that $f(v) \in H^1$.

I am looking for a source of the following (or a similar) result: If $v \in H^1(\Omega,\mathbb{C})$ on a bounded domain $\Omega$ and $f: R(v) \to \mathbb{C}$ is Lipschitz continuous, then $f(v) ...
1
vote
1answer
575 views

Calculator for real and complex parts of a polynomial.

Does anyone know of a nice calculator for calculating the real and complex parts of a complex polynomial. Say, for example, I want to write the polynomial $p(z)=z^3+2z^2+1$ as a function ...
4
votes
1answer
5k 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 ...