
Please post any and all homework or other textbookstyle problems in one of the Homework & Coursework Questions...

Feb2313 09:24 AM
micromass

1 
34,085 
Title says it all really. But basically I'm looking for online info about creating the Leech lattice from the E8...

Jun1911 03:03 PM
Aztral

0 
842 
I just read an article (http://www.maa.org/devlin/devlin_06_08.html) saying that multiplication is not repeated...

Jun1911 06:22 PM
agentredlum

93 
15,800 
What interpretation could the eigenvectors in a graph have? By graph I mean an adjaceny matrix not counting...

Jun1311 08:11 PM
Ackbeet

1 
1,653 
What is the absolute best abstract algebra book for graduate students? I was wanting a book that covers algebra in the...

Jun1511 09:55 PM
ForMyThunder

5 
3,062 
Hi folks,
If I have a Lie algebra \mathfrak{g} with an invariant (under the adjoint action ad of the Lie algebra)...

Jun1411 11:50 AM
SergejVictorov

2 
1,377 
I know that any prime p = 1 mod 4 can be expressed as sum of 2 squares.
But how many different pairs of integers a,b...

Jun1411 08:23 AM
robert Ihnot

7 
2,786 
Hi all,
I have been trying to gain a deeper insight into quadratic forms and have realised that my textbook makes...

Jun1911 12:43 PM
lpetrich

14 
2,678 
I'm trying to find out what the rotation group of a cube is. It seems natural to view it as a subgroup of S_{6},...

Jun1611 03:47 PM
lpetrich

18 
5,316 
Hi, Algebraists:
Say I'm given a group's presentation G=<XR>, with
X a finite set of generators, R the set of...

Jun1811 07:13 PM
Bacle

2 
1,100 
i want to extend the set S={(1,1,0,0),(1,0,1,0)} to be a basis for R4. I know I am going to need 4 vectors, so i need...

Jun1811 04:07 PM
Bacle

6 
6,524 
I want to express the matrix product Ax as a linear combination of the column vectors in A.
I know for that for...

Jun1311 08:17 PM
Mark44

5 
5,067 
For two matrices A and B, when p(A)=0 iff p(B)=0 for any polynomial, what will happen? i read that A and B have the...

Jun1311 02:13 PM
HallsofIvy

2 
1,252 
if i have a 4x3 matrix, this means there are more equations than unknowns and so there are no solutions to the system....

Jun1411 03:19 AM
td21

3 
2,556 
Hi folks. This is something I've been wondering about for a while now. Is there a reason why taking the minimum norm...

Jun1311 10:23 AM
HallsofIvy

1 
822 
Hello all :)
I am studying divisibilities of
1, 11, 111, 1111, 11111 and so on
when I have even number of 1s, in...

Jun1311 08:46 PM
l1jcho

2 
1,537 
Hi, yet another question regarding polynomials :). Just curious about this.
Let f(x), g(x) be irreducible...

Jun1511 08:21 PM
burritoloco

5 
1,379 
In the book I am looking only one of the following is listed as a Jordan Form. Could somebody tell me why the other...

Jun1511 07:05 PM
Zorba

5 
1,127 
I have a nonhomogeneous Ax=b (with b nonzero) and i want to know if the set of all the solution vectors, x, forms a...

Jun1411 04:03 AM
td21

2 
2,290 
I came across this question. How do you show that √N is irrational when N is a nonsquare integer?
Cheers.

Jun1611 07:12 AM
bgwyh_88

2 
2,263 
I have a question I need to resolve before my exam on thursday. It relates to the following result:
Let N be a...

Jun1411 01:25 PM
Zorba

2 
1,093 
Hello,
I am trying to solve a Pell's equation
X2 + 2Y2 =1
I understand that the (3,2) is a fundamental...

Jun1911 10:47 AM
RamaWolf

6 
2,517 
The prime number theorem describes the distribution of the prime numbers, in a sense. Are there other prime number...

Jun1511 08:12 PM
hansenscane

2 
1,781 
Hello :)
I have been giving a mathematical problem. But I find difficulties solving this. Therefore, I will be very...

Jun1611 08:21 AM
micromass

12 
2,201 
Consider the spectral decomposition , let
Gj=xjyjT for j=1,2,3 ,n so that A=sigma (mjGj) .
aShow that each...

Jun1511 11:11 AM
bernoli123

0 
834 
Show that the representation of T with respect to the basis {x1,x2,x3, xn} where xi belong toSi (1 less i less ...

Jun1511 11:13 AM
bernoli123

0 
772 
Consider a) f1=1, f2=sinx , f3=cosx
b) f1=1, f2=ex , f3=e2x
...

Jun1511 11:30 AM
micromass

1 
874 
If \omega is an alternating tensor, then Alt(\omega)=\omega, where Alt is the mapping that maps any tensor to an...

Jun1511 02:52 PM
Office_Shredder

1 
868 
Okay, I know that if I can't get n linearly independent eigenvectors out of a matrix A (∈ℝnxn), it is not...

Jun1911 06:06 AM
td21

3 
1,918 
Given two orthonormal bases v_1,v_2,\cdots,v_n and u_1,u_2,\cdots,u_n for a vector space V, we know the following...

Jun1711 01:44 AM
I like Serena

6 
1,538 
such as some 3D matrix visualization or eigenvalue/singular value things/jordan form?
Thanks very much for any...

Jun1811 10:01 AM
Stephen Tashi

1 
1,662 
I'm wondering why 1/k! is needed in Alt(T), which is defined as:
\frac{1}{k!}\sum_{\sigma \in S_k} \mbox{sgn}\sigma...

Jun1811 10:13 PM
mathwonk

2 
1,188 
Is saying \existsx, \existsy
the same as saying \existsy, \existsx?

Jun1711 10:54 PM
gmmstr827

2 
1,688 
Outside of pure mathematics, where is group theory used?

Jun1811 09:54 PM
mathwonk

6 
2,384 
If Riemann's Hypothesis is proved as true, would number theory collapse?

Jun1811 08:20 AM
Karlx

3 
1,763 
"orthonormal columns imply orthonormal rows for square matrix."
My proof is:
Q^{T}Q=I(orthonormal columns)...

Jun1811 03:53 AM
Fredrik

1 
931 
i have ordered introduction to linear algebra by gilbert strang.But i saw it on google books and found it to be...

Jun1811 09:53 PM
mathwonk

2 
2,992 
Other than the Eucledean method
(1+p1p2p3...)and so on
other than this, how do we prove that there are infinte...

Jun2011 11:46 AM
disregardthat

10 
2,969 
Hi all,
I have problem with regard to illconditioned linear system of solving sets of simultaneous equations using...

Jun1811 02:29 PM
kaizen.moto

0 
1,400 
Sorry if this is a well known thing, but I've noticed this and decided to see how well known it is, also if there is a...

Jun1911 10:14 PM
Antiphon

2 
2,646 
A nonzero alternating tensor w splits the bases of V into two disjoint groups, those with \omega(v_1,\cdots,v_n)>0...

Jun2011 02:18 PM
micromass

1 
1,219 