Math

Skew-symmetric matrix A and I + A
Hi, Problem: Let A be a skew-symmetric matrix over the reals, i.e. A^T = -A. Show that I + A is invertible. Any hints for a proof? -- http://kaba.hilvi.org ... 2 May 2010 18:41

Polynomial used to create Galois field for AES?
Hi There, (My apologies for cross-posting) The following polynomial is used to create a "Galois field" GF(2^8) which is specified in the Advanced Encryption Standard (AES): p(x) = x^8 + x^4 + x^3 + x + 1. However, I checked the polynomial (quickly using Matlab) whether it is primitive. It turns out not to ... 30 Apr 2010 11:43

Chess problem (so to say)
I want to find ALL solutions of this to construct a chess theme impossibility proof, but I don't know how to sort things. 123456 are six fields on the chess board. ABCD are four lines (bishop or rook, whatever). 123 lie on A. 16 lie on B. 25 lie on C. 346 lie on D. A chess piece can move from 1 to 4. (Knight... 30 Apr 2010 00:47

I FINISHED MAKING MY MOVIE! <-----
"george" <gblack(a)hnpl.net> wrote > Ah but this is herc the burke asking these questions about a system he must have 'set up' himself.. A modem? In this day and age ? Sort of negates his claims as to the porno website he claims to run.. Now, is he going to stop crossposting to alt.2600 ? Even George g... 1 May 2010 02:15

thank you, mother's love
Mother’s Love A Mother’s love, is sure to find A way to comfort, ease your mind She knows just how, to build you up When you’re so down, and can’t look up You love the way, she makes you feel Like you’re so special, her ideal Her thought must start, with God above To bring such caring, with such love ... 29 Apr 2010 00:14

Awkward Differential eq.
Thank you both. ... 28 Apr 2010 09:28

octanion
i want to make some calculation in octanion algebra. however when i looke for table of product i was little bit confused. usually i see table like following e0 i, e1 j, e2 k, e3 l, e4 il, e5 jl, e6 kl, e7 i, e1 -1 k −j il −l −kl jl j, e2 −k ... 27 Apr 2010 23:32

A little to the right >>>>>>>>>>>>>>>>>>>>
This is a good one too. http://www.youtube.com/watch?v=mPCvlCJx5O8#t=02m02s --------------------------------------------------------------------------------------- The actual answer to Adam and Eve being alive today was "After creating both of those" RIGHT ON MY FINGER TIP!!! PARANORMAL RESEARCHERS ARE A C... 27 Apr 2010 20:13

Can an unique binary tree be drawn if a preorder, an inorder, and a postorder relationships are given? Does it always exist?
Hi, As stated in the title, I would like to know if, being given three sequences (the preorder, the inorder and the postorder), there is only one binary tree respecting these sequences. If so, it is unique. And, furthermore, does such a tree always exist? Thanks folks. ... 27 Apr 2010 15:39

Trying to obtain free version of On Misere Games by Ranan Banerji and Charles Dunning
Perhaps, this is a bit of a long shot but I am trying to obtain the above paper free of charge. Googling around led to non-free versions. As I said, perhaps I either need to pay for it or lump it, but I thought it might be worthwhile asking. Thank you, Paul Epstein ... 27 Apr 2010 06:32