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

Feb2313 09:24 AM
micromass

1 
35,895 
hi. i have recently become very interested in the idea of the nth roots of unity. i have discovered how to calculate...

Dec509 09:53 PM
Hurkyl

1 
1,328 
I've been sick with mono for the past month and am trying to catch up in my Algebra class, but being so far behind I'm...

Dec509 09:08 PM
HardBoiled88

0 
657 
My question is regarding abstract algebra.
Suppost that B is a 10cycle.
For...

Dec509 12:06 PM
Huyen Nguyen

3 
2,419 
I'm using this formula for my quaternion camera in OpenGL. It works perfectly but I didn't understand how it was...

Dec509 05:20 AM
sarah22

0 
1,091 
How do I take the cross product of Two 3x3 Matrices.
For example what is cross product of:
x

Dec409 09:09 AM
dellatorre

5 
10,105 
In short: does every vector space have a "standard" basis in the sense as it is usually defined i.e. the set...

Dec409 06:16 AM
HallsofIvy

4 
3,090 
My textbook doesn't seem to explain it clearly enough for me to comprehend. But from what I can see, after getting the...

Dec409 06:02 AM
HallsofIvy

2 
13,465 
Suppose that p and q are odd primes and p=2q+1. Suppose that
α∈ Z_p^*,α≢±1 mod p.
Prove that α is primitive...

Dec309 08:03 PM
robert Ihnot

4 
3,504 
dear all
how do you find the eigenvalues and eigenvectors of a complex matrix?
0 ; i ; ...

Dec309 04:02 PM
elibj123

1 
4,763 
Define T: F^2 > P_1(F) by T(a, b) = a + bx (with P_1 denoting P sub 1)
I usually prove problems such as this...

Dec309 08:10 AM
dmatador

2 
4,066 
Hello,
I wonder if somebody could point me to a book (preferably), or paper, link, etc. which explores the relations...

Dec309 02:01 AM
dodo

6 
2,146 
So I found the characteristic equation of a matrix, and I know the roots of the equation are supposed to be the...

Dec209 06:02 PM
CompuChip

1 
935 
Hello
Lately, I have been studying some group theory. On my own, I should add, so I don't really have any professor...

Dec209 05:30 PM
0xDEADBEEF

3 
902 
I have a vector of all ones in ndimensions. For example (1,1,1) in 3D. I want to find a invertible rotation matrix T...

Dec209 01:21 PM
bohdy

8 
2,000 
Hi guys just a quick question on how I would go about showing the units of Z21 is isomorphic toC2*C6(cyclic groups).I...

Dec209 08:53 AM
rochfor1

5 
1,035 
http://i45.tinypic.com/b7nfig.jpg
I started by saying
cince c = me mod n (1)
then me ≡ c mod n
Since...

Dec209 08:05 AM
Firepanda

0 
943 
I'm trying to follow some notes in class.
so the original equation is:
u=
and we let x=z+1.
Then by...

Dec109 09:47 AM
CompuChip

1 
956 
So I have a system of equations (composed of force and moment eqns) and I can split them up into matrices which will...

Dec109 03:30 AM
trambolin

9 
28,153 
Hello,
I am looking into proving that the Chinese Remainder Theorem will work for two pairs of congruences IFF a...

Dec109 02:01 AM
dodo

2 
2,457 
If we call <a> the "span" of a, then I need some clarification on the concept of span.
def. if G is a group and...

Nov3009 06:23 PM
kjartan

1 
837 
Hi, I have spme questions about Fermat's little theoremhttp://en.wikipedia.org/wiki/Fermat%27s_little_theorem.
I...

Nov3009 07:04 AM
Dweirdo

2 
1,243 
Ok so i was thinking about it recently, why do we use the decimal system as opposed to other counting systems in math?...

Nov3009 06:34 AM
hamster143

18 
3,315 
I am having trouble getting my head around typical arguments involving natural transformations. Is there anyway...

Nov2909 01:44 PM
icantadd

0 
698 
H,K are normal subgroups of a (finite) group G, and K is also normal in H. If G/K and G/H are simple, does it follow...

Nov2909 09:03 AM
Bleys

6 
1,202 
Let me start by saying I do not have a lot of background in linear algebra, but I'm not afraid of learning. I am...

Nov2909 07:07 AM
HallsofIvy

1 
1,539 
How do I find all irreducible matrix representations of group d4?

Nov2909 07:04 AM
VINAYBAR

0 
2,568 
Okay, so I'm trying to finish of a problem on integral closure and I am rather unsure if the following fact is true: ...

Nov2809 11:17 AM
Hurkyl

5 
1,197 
Hi!
This might be a silly question, but I can't seem to figure it out and have not found any remarks on it in the...

Nov2709 05:10 AM
FredMadison

4 
879 
Given:
G is the group of matrices of the form:
1 n
0 1
Where n is an element of Z, and G is a group under...

Nov2609 10:54 PM
Myriadi

3 
1,297 
Hello,
I have an infinite monoid A and a submonoid K.
let's assume I pick up an element x\in AK,
now I consider...

Nov2609 05:24 PM
mnb96

2 
773 
I was reading "Principles of Quantum Mechanics"  Shankar, and I'm having trouble understanding the inner product. Can...

Nov2409 09:09 PM
Identity

2 
823 
Is there a name for product of the unique prime factors of a number?
For example, for the number 12, it would be...

Nov2409 03:01 PM
Elam

1 
2,347 
If H is a nxn primitive, irreducible matrix, is it always true that Hn1 > 0? That is, every entry in Hn1 is...

Nov2409 12:51 PM
Doom of Doom

1 
2,749 
Does anyone know how to approach this problem?
Let A be an m×n matrix of rank m, where m<n. Pick a point x in R^n,...

Nov2309 09:58 PM
hoffmann

6 
2,857 
First, remember that the OP is new to pure number theory.
We all know that not every number that follows the...

Nov2309 06:39 PM
robert Ihnot

5 
1,896 
Figured it would be a quick review of ideas that turned into a nightmare...
x \equiv i (mod 1 + i)
x \equiv 1...

Nov2309 03:36 PM
math_grl

0 
893 
I read this in a book (it was stats and about poisson approx to normal)
Given was this:
n(n1)(n2) \cdots (nr+1)...

Nov2309 10:42 AM
hamster143

2 
4,812 
fin all natural numbers n that n\sigma (n) \equiv 2(mod\varphi(n))

Nov2109 05:51 PM
hamster143

5 
1,473 
There is something I don't understand about the recent concept of a "number derivative". It seems to me that the (very...

Nov2109 06:01 AM
dodo

0 
1,409 
If C = A +B where A,B are both p.d, than C is p.d and its eigenvalues are positive.
Waht can you say about the...

Nov2009 02:16 PM
trambolin

2 
3,570 