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

Feb2313 09:24 AM
micromass

1 
35,776 
I'm unable to understand this generalization of vectors from a quality having a magnitude and direction, to the more...

Jan1413 10:29 AM
danzibr

4 
1,402 
In this video:
http://www.youtube.com/watch?v=FZzQKBlpE
At the time 2:10, I don't understand why we have to...

Jan1413 07:15 AM
Artusartos

4 
1,089 
Perhaps forum members can advance science by solving this optimization problem from The Protein Engineer ...

Jan1313 04:10 PM
homeomorphic

2 
861 
I don't know if this is the correct section to post this, but does Galois theory has any applications in physics?

Jan1313 03:47 AM
Jim Kata

2 
2,006 
Pretty much what the title says.
Suppose we have a topological vector space $(X,\tau)$ and $U\subseteq X$ is...

Jan1213 09:32 AM
danzibr

5 
1,281 
Hi all,
I have been asked the question by a friend of mine who was working on a computer algorithm where he needed...

Jan1113 03:01 PM
HallsofIvy

4 
1,280 
Hello all,
I am new to this forum but am glad I found it, I have a quick question about condition numbers and order...

Jan1013 06:08 PM
AlephZero

5 
1,227 
Hello,
I was wondering if this problem is one that is solvable, and if so, if I would be able to solve it in a...

Jan913 11:31 PM
hello95

3 
1,104 
Hey guys, lurked here a bit, but now I'm in this new math course right. So anyway it seems like a completely new...

Jan913 06:59 PM
sniper_spike

4 
849 
Hi guys, first post!
I'm doing some side work on coupled oscillating systems, and I've almost found a procedure to...

Jan913 03:39 PM
Jack Jenkins

0 
917 
Hi,
Let the linear system Ax=b.
I am looking for literature describing how changes on coefficients matrix A affect...

Jan813 05:01 PM
yiorgos

0 
619 
I'm trying to understand the derivation of polynomial regression.
Given data points: . So a 2nd degree curve will...

Jan813 02:58 PM
SteamKing

10 
1,241 
I have a question about the proof that I attached...
1) Since R/I is not the zero ring, we know that 1 \not= 0....

Jan713 09:01 PM
Number Nine

1 
834 
I recently got (re)interested in C* algebras. Poking around, I gathered that there is some way of constructing a C*...

Jan713 12:17 PM
marcus

0 
568 
Hi
I am going through Sheldon Axler  Linear Algebra Done right. The book States the Complex Spectral Theorem as :...

Jan713 11:38 AM
vish_maths

4 
1,138 
No not the trival solution but generally GCD(x,y) = 1 when GCD(A,B)=1
x =...

Jan713 12:40 AM
ramsey2879

0 
1,009 
Hello everyone!
I'm a 1st grade student in a slovenian high school. Recently, I've became very intrested in numbers...

Jan613 09:22 PM
skiller

11 
2,337 
I have some technical questions about spans and bases which my textbook really does not cover very well. I would...

Jan613 06:16 PM
AlephZero

2 
917 
I have no idea what this is! Please can someone explain comparing to a 3x3 matrix?

Jan613 05:19 PM
mfb

3 
1,102 
Hello all,
I have a question:
assume in matrix M(n*n), each element M(i,j) of matrix is computed as M(i&)*M(&j) /...

Jan613 01:06 PM
sanaz

4 
997 
I am a bit confused about the page that I attached...
I don't understand part (ii)...
How can you compute XX? So...

Jan613 12:07 AM
Artusartos

6 
831 
Why do we have xaxis perpendicular to yaxis? Why not 45° or something else?
Even if we keep any other angle other...

Jan513 12:16 PM
Studiot

9 
1,624 
I'm trying to compute the complexity of the quadratic program: $$\displaystyle\min_{\mathbf{X}} (\mathbf{X^TQX +C^TX})...

Jan313 08:41 PM
lavinia

3 
762 
Consider an m x n table containing single digits 0 to 9. So each cell contain the digits 0 to 9.
My goal is to make...

Jan313 11:01 AM
mfb

7 
2,234 
Hi. Define a linear mapping F: M2>M2 by F(X)=AXXA for a matrix A, and find a basis for the nullspace and the...

Jan213 11:59 PM
nickthegreek

2 
916 
Hello, I have a simple(or not?) math problem:
I have equations of 3 lines in R3 trought the origin:
line l1:
...

Jan113 08:12 PM
chiro

5 
1,384 
Theorem :
if S ={ v1 , .... , vn} spans the V.Space V
, L={w1 , .... , wm} is set of linear independent vectors...

Jan113 07:55 PM
mathwonk

10 
1,549 
The logic that odd composite with least difference will be factored easily and large difference would factored hardly...

Jan113 09:30 AM
mfb

4 
1,634 
Hello everyone,
I found that you're actively discussing math problems here and thought to share my problem with...

Jan113 03:33 AM
phd_student

0 
1,006 
Suppose that a = aBc where a and c are vectors and B is some matrix that changes as time "continuously" goes on ...

Dec3112 04:20 AM
dotiozeros

0 
805 
Hey all, I have been playing around with a special type of matrix and am wondering if anyone knows of some literature...

Dec3012 11:21 PM
orthogonal

4 
1,455 
Hi All,
I have a hard time answering the following. I need some help.
Let Z={a,b,c,d,e,f} and let X denote the...

Dec3012 01:31 PM
laptopmarch

1 
742 
Is there any algorithm to form a magic square of any size with a desired magic sum ?
Also can we make a magic square...

Dec3012 08:09 AM
RamaWolf

6 
2,108 
The book I am going through says this :
The below proposition is false for real inner product spaces. As an...

Dec2812 06:46 PM
chiro

3 
994 
I was looking for a hint on a problem in my professor's notes (class is over and I was just auditing).
I want to...

Dec2812 06:42 AM
sammycaps

12 
1,295 
Question is :
If m,k,n are natural numbers and n>1, prove that we cannot have m(m+1)=kn.
My attempt :
Using...

Dec2712 12:16 PM
mathwonk

16 
2,982 
This may be a very silly question, but still apologies, I read in Sheldon Axler, that the inner product of two...

Dec2712 07:31 AM
vish_maths

3 
855 
Hello,
I was wondering, why is the vector projection useful in the way that it is presented? Why isnt just the...

Dec2712 03:30 AM
Stephen Tashi

12 
2,204 
I've got a general question about Lie algebras, which is basically this:
Q: What is there to be said about the Lie...

Dec2712 01:10 AM
Couchyam

0 
758 
Video illustration
Hello,
Me and a friend, David Barrack, are nonmathematicians but we've been having fun...

Dec2512 11:34 AM
micromass

2 
2,039 