Math

why isnt sqrt(x^2 + y^2) a polynomial?
why isnt sqrt(x^2 + y^2) a polynomial? Thanks in advance! Mike ... 22 Jul 2010 05:57

Books on complex analysis
Hi I'm somewhat young (15) but I have studied some math. I started at number theory, but then I was introduced to analysis and found it very interesting. And I know it's very important in several practical fields like engineering, economics and optimization. I've been studying it for almost 2 years, in Rudin's a... 8 Jul 2010 03:44

MetaOptimize Q+A site
Question: What is an accurate technique for computing the moving variance? Answer: http://metaoptimize.com/qa/questions/287/what-is-an-accurate-technique-for-implementing-moving-variance I have just launched a machine learning + statistics Q&A site: http://metaoptimize.com/qa/ I announced it initially to ML... 4 Jul 2010 00:25

Jacobian determinant from non square Jacobiam matrix (and Stokes' Theorem)-
Nando wrote: Hello! I have parametrized an ellipse in order to calculate its area by an integral. In the end I will explain the whole problem (this is a sort of homework assignment). The ellipse is defined in R^3, z= 0; and x^2 /20 + y^2 /30 = 1 my parametric function is: (let "p" stand... 10 Jul 2010 10:31

The Necessary vs Contingent Distinction
The distinction between contingent and necessary statements is one of the oldest in philosophy. A truth is necessary if denying it would entail a contradiction. A truth is contingent, however, if it happens to be true but could have been false. For example: Cats are mammals. Cats are reptiles. Cats ... 3 Jul 2010 23:21

Website devoted to differential equations
A Website Devoted to Differential Equations A couple of months ago we posted a message here to announce the availability of a new website, devoted to the subject of Differential Equations, and whose goal will be to present that subject in an as an intuitive and conceptual a way as possible. The URL is: ... 3 Jul 2010 21:09

Results that are much more fun
"JSH" <jstevh(a)gmail.com> wrote in message news:7078bb23-eec6-4fd3-82bf-9d86edb7db88(a)x2g2000prk.googlegroups.com... It's almost a relief now to have the results around residues as so much of my research seemed to just kind of go over old ground--in simpler ways, yeah, but still areas where other research wa... 6 Jul 2010 00:21

JSH: Results that are much more fun
It's almost a relief now to have the results around residues as so much of my research seemed to just kind of go over old ground--in simpler ways, yeah, but still areas where other research was available--or in the case of Fermat's Last Theorem, supposedly just proved a negative. And I say supposedly as YEARS ago ... 4 Jul 2010 05:48

details re Z-R |- PA consistent
In recent threads it has been questioned whether ZFC proves the consistency of first order PA (called 'PA' in this post). This post provides a proof in Z-R (Z set theory without the axiom of regularity) of the consistency of PA, thus perforce ZFC proves the consistency of first order PA.. In order to be clear for c... 13 Aug 2010 12:30

Does This Infinite Sum Equal 0 for all n?
Let H(0,m) = 1/m for all positive integers m. Let H(n,m) = sum{k=1 to m} H(n-1,k), for all positive integers n. (So, H(1,m) = the mth harmonic number, 1 + 1/2 + 1/3 +... + 1/m.) Let, for all positive integers k, j(2k) = i, the squareroot of -1. Let , for all positive integers k, j(2k-1) = 1. Does 0 = sum{k... 5 Jul 2010 11:05