Math

COOPERS PROOF ON UNCOUNTABLE INFINITY
On Jun 4, 8:12 pm, Rick Decker <rdec...(a)hamilton.edu> wrote: Err, no, unless you're using a non-standard definition of "uncountable." In fact, the set {1, 2, 3, ... } is countable, in the agreed-upon definition of the term. Err, no; in case you hadn't noticed, Herc does NOT agree. Moreover, he is even ex... 5 Jun 2010 00:38

Give me ONE digit position of any real that isn't computable up to that digit position!
On Jun 4, 8:13 pm, Charlie-Boo <shymath...(a)gmail.com> wrote: On Jun 4, 8:22 pm, "dannas" <inva...(a)invalid.com> wrote: "|-|ercules" <radgray...(a)yahoo.com> wrote in message A computer can calculate ANY digit sequence up to INFINITE length. not infinite, as that would take infinite power, and the... 16 Jun 2010 09:57

Cardinal of C
Is |C| = 2^aleph0 or |C|= 2^2^aleph0? where C is the usual set of all complex numbers on the usual field R. I couldn't put a bijection between R and C. But of course, I'm not much of a mathematician. Is there one? Pollux ... 5 Jun 2010 08:08

Welsh's Matroid Theory book is back in print
Welsh's book "Matroid Theory" is now back in print (Dover Press). Longtime readers of sci.math may recall that a couple of years ago I mentioned here that I was trying to get this book back in print. Much of the feedback I got was to the effect that I was wasting my time and that all books would be electronically... 4 Jun 2010 22:28

Network Working Group M. Musatov, Editor Request for Comments: MEAMI.ORG/2136.HTM ISC Updates: 1035 S. Thomson Category: Standards Track
Network Working Group M. Musatov, Editor Request for Comments: MEAMI.ORG/2136.HTM ISC Updates: 1035 S. Thomson Category: Standards Track Bellcore Y. Rekhter Cis... 4 Jun 2010 18:07

Convert to General Conic
If a parabola y = ax^2 + bx + c is rotated through an angle t, how can one determine the corresponding coefficients of the general parabola Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0, where B^2 = 4AC? Also, the reverse question, given the coefficients of a general parabola, how to find the coefficients of the 'normal' pa... 5 Jun 2010 07:04

Density of Q in R
Hi- I'm only a beginner in topology, so please no flames... Here is my question: if almost all reals are not rationals, should it be the case that for any two rationals, there is an infinity of reals "between" them? But Q is dense in R, so I can always find a rational as close to any real as I want, there are no "ga... 4 Jun 2010 22:28

Matrix A + B - Author of book "Applied numerical linear algebra"?
Kaba wrote: Hi, This is part of the first question for chapter 1 of "Applied numerical linear algebra" book, but I just can't come up with a solution: If A and B are orthogonal matrices, and det(A) = -det(B), show that A + B is singular. Any hints? Beautiful theorem - I guess th... 4 Jun 2010 18:06

THE HONOR OF YOUR GREAT MAHEMATICIAN PROF ESCULTURA / MATHEMATICS MONUMENT
On Jun 4, 12:17 pm, Inverse 19 mathematics <hope9...(a)verizon.net> wrote:  Right or wrong, we will honor this PHD , one of your own, for the very hard mentoring that he gave us, so you liked it better than with your farm's donkey? ... 4 Jun 2010 17:00

Tough queueing question
Let Q denote a queue. Let r(i) denote Q's size at time-slot i. Let A_i be i.i.d. random Bernoulli variables. Let B_i be i.i.d. random Bernoulli variables. At each timeslot i: if (A_i == 1) { if (r(i) > 0) {remove one packet from Q;} if (B_i == 1) {schedule one packet to enter Q in K slots from now, i.e. in... 4 Jun 2010 18:07