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

Feb2313 09:24 AM
micromass

1 
30,480 
Hi,
I'm pretty rusty with solving linear equations, my equations are:
ai = bijkcjk
i = 1,... n
j, k = 1,......

Jul2211 12:01 PM
Ben Niehoff

6 
2,157 
I do not know if this is a common/standard construction, so here is my motivation for this question. From Crystal...

Jul2111 09:06 AM
kdbnlin78

2 
1,656 
Why is the transpose of a matrix important?
To find the inverse by cofactors we need the transpose but I would never...

Jul2111 08:45 AM
kdbnlin78

2 
1,291 
I am a physicist, so my apologies if haven't framed the question in the proper mathematical sense.
Matrices are...

Jul2111 06:17 AM
rkrsnan

5 
1,435 
I have observed a strange thing when you modify a sequence of numbers bit by bit.

Jul2011 07:08 PM
ramsey2879

2 
2,512 
I'm looking for the title to a popular introductory book on graph theory. For the best possible recommendation,...

Jul2011 12:02 PM
tbrown122387

3 
1,693 
Hi, I need help with simply starting to prove this. I'm terrible with proofs and even the easy ones are hard for me....

Jul1911 07:01 PM
BWElbert

1 
2,708 
Is there an "easy" method to finding subgroups of finitely generated abelian groups using the First Isomorphism...

Jul1911 12:16 PM
micromass

1 
1,227 
For a dimension 1 regular semilocal ring, does the Picard group vanish?
What if it is not regular? (and what if I...

Jul1911 09:40 AM
Hurkyl

2 
1,342 
Why is it not possible for a filed to have have two prime fileds one isomorphic to Zp and the other isomorphic to Zq ...

Jul1911 03:11 AM
SteveL27

1 
795 
Lemma. A group G of order 6 can have only one element of order 3.
Pf. Suppose G has two elements of order 3. Call...

Jul1811 08:22 PM
Samuelb88

12 
977 
I am trying to ultimately find the projector onto a convex set defined in a nonexplicit way, for a seismic processing...

Jul1811 02:02 PM
Squatchmichae

2 
766 
Ok, so the title didn't allow me to be too descriptive. Basically, I'm trying to formulate a variant of the time...

Jul1811 10:05 AM
jambaugh

1 
2,077 
Hey all,
I was hoping someone could explain to me how to calculate the angle between matrices, ie. two square...

Jul1711 08:36 AM
unusualname

4 
3,820 
I recently got interested in number theory and have been fiddling around with Scilab trying to find interesting...

Jul1711 02:37 AM
cubzar

8 
4,746 
So if G = Q8 = <a, b : a^4 = 1, b^2 = a^2, b^{1}ab = a^{1}>
I'm fine with the notion of the derived subgroup G' =...

Jul1611 07:53 PM
micromass

1 
1,751 
Hello,
I'm wondering if there's some nice formula for the expansion of trinomials, like this:
\prod_i \left(y +...

Jul1511 07:04 PM
burritoloco

2 
1,862 
I have a matrix of the form X = , where A and B are matrices of equal dimensions (M x N). I am looking for an elegant...

Jul1511 05:32 PM
chogg

11 
2,326 
Hello. I'm quoting Bertsimas, D., and J. Tsitsiklis, Introduction to Linear Optimization:
"For the purposes of this...

Jul1411 05:46 PM
nancyiskander

0 
1,191 
I'm trying to learn linear algebra using Schaum's outline and this is one of the practice problems:
Find and...

Jul1311 02:19 PM
cowmoo32

3 
1,301 
Hi,
Quick question here: I know that CS inequality in general states that
<x,y> \leq \sqrt{<x,x>} \cdot...

Jul1311 07:57 AM
Lajka

8 
1,718 
I know you can decompose GL(3,R) into SO(3) x Diag x SO(3), but i was wondering if you could generalise this to a set...

Jul1311 07:09 AM
em12

0 
1,007 
I am trying to take the derivative of an
inner product (in the most general sense
over L^2), and was curious if...

Jul1311 06:17 AM
tinytim

1 
2,763 
Hi there.
We know that Convolve = f if g = diracdelta. My question is, what should be g so that Convolve = f where...

Jul1311 05:23 AM
brydustin

2 
1,165 
Hello all, I'm really sorry that this may come across as a ridiculously simple question, but I'm taking a linear...

Jul1311 05:11 AM
brydustin

8 
1,996 
This is from "Prime factorization of integral Cayley numbers" by H.P. Rehm
...

Jul1211 07:28 PM
UD1

0 
792 
Hi,
I already posted this in solid state physics forum, but no one answered, so I guess this topic might belong to...

Jul1211 01:37 PM
Lojzek

0 
645 
I have attatched my Paradox for the existence of 4,5 and 7 using Brocard's problem . I don't know where i have gone...

Jul1211 03:31 AM
atomthick

3 
2,462 
max ( Ax)/(x) , where x is not 0. A is a matrix.
It said that the stationary point are the right...

Jul1111 08:09 AM
wall_e

0 
729 
helloo
while working on a combinatorics problem I have found the following result:
let A=(a_{ij})_{1\leq...

Jul1011 07:54 AM
micromass

3 
1,541 
Hi everyone!!
I can't figure out why electromagnetism is defined a non integrable phase factor (or path dependent),...

Jul911 01:57 PM
lennyleonard

0 
909 
I've been enormously impressed with the core members of this forum, especially hurkyl. There was a guy who claimed to...

Jul811 07:13 PM
micromass

20 
4,882 
Here is a visual prime pattern:
http://plus.maths.org/content/catchingprimes
I have developed one of my own based...

Jul811 03:56 PM
JeremyEbert

112 
25,325 
Where did the binomial theorem come from.....???

Jul811 12:28 AM
quantizedzeus

6 
1,904 
I'm working my way through Shaum's Outline on linear algebra and in it they define a complex number as an ordered pair...

Jul711 02:58 PM
HallsofIvy

3 
1,484 
Hi,
While trying to solve an optimization problem for a MIMO linear precoder, I have encountered the need to...

Jul711 12:40 PM
lanedance

1 
1,788 
Hello,
I am unable to grasp the significance of adjoint operators both in linear vector space as well as function...

Jul711 08:11 AM
micromass

8 
2,753 
I got this question from another
forum and it's driving me crazy.
Find all triples of odd primes,
p,q,r such that
...

Jul611 10:26 PM
agentredlum

2 
2,317 
Hi all,
I've developed a new sieving method that I believe provides a tight lower bound for the counting of certain...

Jul611 07:19 PM
SteveL27

3 
3,145 
Does anyone know the answer to this problem: if you have a set of consecutive prime numbers (2,3,5,7...), what is the...

Jul611 07:18 PM
kid1

5 
3,047 