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

Feb2313 09:24 AM
micromass

1 
30,539 
Hi,
I am trying to understand how I find the error in linear regression, and what to do with it. I am using linear...

Jun2213 11:56 AM
Stephen Tashi

7 
583 
There are lots of examples of numbers where "is it a rational number" has been an open question for a while before...

Jun2113 01:54 PM
Office_Shredder

0 
356 
I am having problems showing the following:
##f## and ##g## are two linearly independent functions in ##E## and...

Jun2113 02:06 AM
Tenshou

2 
609 
I have some reason to believe that
\det(\textrm{id} + AB) = \det(\textrm{id} + BA)
is true even when AB and...

Jun2013 10:47 PM
jostpuur

2 
422 
Can someone please explain the below proof in more detail?...

Jun2013 08:04 AM
DrClaude

12 
887 
In my work I've encountered equations of the type:
(Ax).*(Bx) + Cx = d
Where A,B and C are nonunitary square...

Jun1813 03:28 PM
DuncanM

3 
487 
I have sets of 2d vectors to be transformed by an augmented matrix A that performs an affine transform.
Matrix A can...

Jun1813 12:24 PM
atrus_ovis

6 
734 
I've been studying the proof of the MazurUlam theorem in the pdf linked to at the end of this Wikipedia article. I'm...

Jun1713 09:59 PM
micromass

7 
714 
Here is the problem:
Let f be a realvalued function on the plane such that
for every square ABCD in the plane,...

Jun1713 07:42 PM
hello95

7 
483 
So,
I just went through the derivation of the Lie algebra for SO(n). in order to do so, we considered...

Jun1713 12:15 PM
pdxautodidact

0 
478 
Suppose A and B are matrices of the same size, and x is a column vector such that the matrix products Ax and Bx are...

Jun1713 06:44 AM
lurflurf

2 
562 
I have some question guys
i have four points in the x,y plane in cartesian coordinates.
A (Ax,Ay)
B(Bx,By)
...

Jun1713 05:18 AM
Fredrik

5 
417 
This is slightly applied stuff. Please look at the PDF attached.
How do we express the function f(n)ij, found at...

Jun1413 05:33 PM
BigDaddy

14 
856 
"Let R be a commutative ring. We say that M is an algebra over R, or that M is an Ralgebra if M is an Rmodule that...

Jun1313 10:53 AM
Artusartos

4 
496 
I have begun to learn about maximal elements from a linear algebraic perspective (maximal linearly independent subsets...

Jun1313 06:58 AM
HallsofIvy

1 
406 
Hi all,
I'm testing out a matrix solving program and while it checks out for 2x2/3x3/4x4 I would like to try it out...

Jun1213 06:12 AM
Kosh Naranek

1 
412 
Hi everyone. I'm trying to understand the step where they wrote
1/2 ∏1/(1+p^3) =1/2 Ʃ(1)^ord(k)/k^3
How can I...

Jun1213 03:16 AM
lurflurf

7 
533 
Was wondering if the only required definition for finite groups is closure (maybe associativity as well). It seems...

Jun1213 02:13 AM
lurflurf

16 
997 
For a linear transformation to be invertible, is it a requirement that the domain and codomain be the same vector...

Jun1113 08:26 AM
HallsofIvy

3 
421 
Friedberg proves the following theorem:
Let V and W be vector spaces over a common field F, and suppose that V is...

Jun1013 12:25 PM
micromass

1 
417 
Is there a way without using the algorithm to find A1 of a square matrix greater than 2x2?
The question we are...

Jun913 11:04 AM
dwn

2 
628 
For a certain transformation T, it is known that T(x+y) = T(x) + T(y)
It is required to determine whether this...

Jun913 10:24 AM
micromass

5 
510 
Resource: Linear Algebra (4th Edition) David C. Lay
I understand that there are identities associated with...

Jun913 08:32 AM
dwn

4 
478 
How does one show that the set of polynomials is infinitedimensional? Does one begin by assuming that a finite basis...

Jun913 12:39 AM
Bacle2

6 
894 
Let's say I have some finite subset of vectors in, lets say, ℝ^{5} . If my set has five linearly independent vectors,...

Jun813 10:54 PM
Vorde

6 
574 
First I'll write what I know:
Algebraic number: one of the roots to a polynomial over rational numbers.
...

Jun813 09:06 AM
Stephen Tashi

1 
530 
The definition given is...
"Let ##\phi: G \rightarrow H## be a homomorphism with kernel ##K##. The quotient group...

Jun713 07:47 PM
Office_Shredder

7 
576 
I am reading a number theory text book that states Dirichlet's Approximation Theorem as follows:
If α is a real...

Jun413 03:31 AM
ANphysics

2 
465 
Hello,
I would like to know if it is possible (and the solution, if known, please!) to extract a 3x3 matrix from a...

Jun313 05:45 PM
mfb

7 
544 
Hello, I'd like to make a, probably stupid, question regarding the axioms that define a vetor space. Among them, there...

Jun313 10:22 AM
cosmic dust

3 
485 
Is the following a theorem? yes or no
If A and B are noncommuting Hermitian operators (or matrices), there does not...

Jun213 12:28 PM
nomadreid

2 
732 
Are any of the nondivision algebras similar to the grassmann algebra?

Jun113 05:06 PM
friend

4 
673 
Hi all!
I have no application in mind for the following question but it find it curious to think about:
Say that...

May3113 06:43 PM
mfb

1 
422 
Remember the Newton's binomial theorem which says:
(x+y)^n = \sum_{r=0}^n {n \choose r} x^{nr} y^r
where {n...

May3113 12:13 PM
Stephen Tashi

3 
536 
Consider ##\vec{a}=\begin{bmatrix} a_1 \\ a_2 \\ a_3 \end{bmatrix}## and ##\vec{b}=\begin{bmatrix} b_1 \\ b_2 \\ b_3...

May3013 11:53 AM
Ben Niehoff

15 
829 
Hey,
Can somebody help me on this one. I feel out of my depth and have to solve it somehow.
I have a variable...

May3013 06:58 AM
alnoy

2 
443 
Using the given information, is it possible to solve the new travel direction of the smiley face? To clarify, I am...

May2913 06:48 PM
Simon Bridge

6 
419 
The invertible matrix equation tells us that the following statements are equivalent, for any square matrix A:
1) A...

May2913 07:39 AM
HallsofIvy

2 
579 
Consider the operation of multiplying a vector in ℝ^{n} by an m \times n matrix A. This can be viewed as a linear...

May2813 03:39 PM
CompuChip

4 
476 
Here it is for those interested.
http://arxiv.org/pdf/1305.2897.pdf

May2813 08:47 AM
epsi00

0 
407 