Math
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integral problem how to get integral of (1/x)[e^(-ax)-e^(-bx)] from 0 to infinity ... 5 Dec 2005 10:56
The set of All sets Hello everyone. Define U to be the set of all x were x fulfilles the propositional function P(x) = x. U = Set of All sets , because everything is identical to itself. If U can be identical to itself. and so a subset of itself. then P(P(x)) = P(x) so U = { U } P(P(P(x)))= {{U}} This can go for... 19 Dec 2005 06:48
The proof of mass vector. The proof of mass vector. Ka-In Yen yenkain(a)yahoo.com.tw http://www.geocities.com/redlorikee Introduction: In this paper, we will prove that linear mass density and surface mass density are vector, and the application of mass vector is presented. 1. The unit of vector. In physics, The unit of three-d... 20 May 2007 22:12
infinity ... (Hint: The sketches would not looks good in proportional fond) Let's start with a representation of the natural numbers in unitary (1-adic) system as follows: O O O O O O O O O ... O O O O O O O O ... O O O O O O O ... O O O O O O ... O O O O O ... O O O O ... ... 9 Nov 2005 22:11
divisor problem Perhaps somebody knows the solution of or a reference for the following problem. A number G of n digits has the property that the number formed by the first k digits is divisible by k, for k = 1,2, ... , n. Find such a number G with a maximal number of digits. Thanks for any help! C. Wildhagen Rotter... 18 Aug 2005 14:27
Sudoku My uncle is possessed with Sudoku. He spends hours marking and erasing but he finally solves it. He is a civil engineer and also has a Microsoft certificate for Excel usage, or something like that. I suggested he ported the game to Excel, using a template, so he doesn't have to scratch and erase all the time. ... 26 Sep 2005 03:13
How many Primes? Is there a formula that gives me the amount of Prime numbers in a Finite subset of N? In other words, is there a formula that, for every n (Natural number), gives us the number of primes < n? Thanks in advance, Apple Pi ... 12 Aug 2005 11:53
MONOTONE SET FUNCTIONS, FIXED POINTS, AND CECH CLOSURE FUNCTIONS I'm starting a new thread because others who might be interested may overlook this post if I put it in the thread "Finite topology spaces", and to make this post easier to show up for anyone in the future using the sci.math archives in order to look up something about what I discuss here. Herman Rubin wrote: ... 13 Jul 2005 18:12
variance of product of uncorrelated variables Let X and Y be uncorrelated random variables. By construction, this means Cov[X,Y] = 0. Is there a simple expression for Var[XY]? Or for Cov[XY,X]? (I don't imagine that Var[XY] = Var[X] * Var[Y] + ???) Kenneth ... 27 Jun 2005 10:39 |