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

Feb2313 09:24 AM
micromass

1 
34,867 
Hi!
I have a question concerning solving a system of linear equations. I know that the pseudoinverse matrix by...

Sep213 09:50 PM
brmath

2 
935 
Question regarding Kronecker Delta and index notation
I am reading a book which covers the Kronecker delta and...

Sep213 08:51 PM
TheFerruccio

16 
1,844 
Hi,
The following equations are from linear regression model notes but there is an aspect of the matrix algebra I...

Aug3013 09:47 PM
chiro

1 
710 
Trying to make sense of the following relation:
\sum log d_{j} = tr log(D)
with D being a diagonalized matrix.
...

Aug3013 05:57 PM
dm4b

3 
752 
The context in which this question arises (for me), is I was trying to take the curl of the magnetic field of a moving...

Aug3013 05:43 AM
chiro

3 
823 
For example, if were given only a vector <5, 3, 1>, is this assumed to be respect with the standard basis of R^3?
...

Aug2913 08:09 PM
Simon Bridge

10 
1,027 
Given A(m,n), eps = Machine Epsilon, fNorm = FrobeniusNorm(A), p >= 1
To filter noise near zero created by floating...

Aug2913 11:44 AM
AlephZero

1 
675 
We know that the Newton binomial formula is valid for numbers
in elementary algebra.
Is there an equivalent formula...

Aug2813 05:31 PM
francesco75

4 
806 
Hello folks, I'm not even sure if this is the place to put this but with some luck it might be.
I just have a...

Aug2513 07:28 PM
eigenperson

5 
905 
Hi,
I have a matrix with N rows and K\cdot M \ll N columns.
Is there a generic way to choose L rows s.t. the...

Aug2513 02:34 PM
Stephen Tashi

3 
838 
Suppose that V and W are finite dimensional and that U is a subspace of V. If dimU≥dimVdimW prove that there exists a...

Aug2513 07:33 AM
HallsofIvy

6 
1,007 
Hello!
The following system of linear equations
has been expressed in term of column vector in the following....

Aug2313 09:19 AM
HallsofIvy

5 
1,228 
If u=(3, 3 , 3) is a vector in R3 then we can draw the vector in a three dimensional space.(3=x coordinate, 3= y...

Aug2213 01:24 PM
HallsofIvy

3 
636 
Suppose that ##A## is a diagonalizable ## n \times n ## matrix. Then it is similar to a diagonal matrix ##B##. My...

Aug2013 08:54 AM
mathwonk

5 
1,033 
Is there a term for the least k such that a^k = 1 in some ring R (if it exists, specifically in a finite ring)? Is...

Aug1913 12:50 PM
micromass

1 
719 
Hello,
I'm following the proof for this theorem in my textbook, and there is one part of it that I can't...

Aug1913 10:17 AM
TheShrike

4 
1,004 
Hi,
Lets say that I have a 4x4 matrix, and am interested in projecting out the most important information in that...

Aug1813 12:26 PM
AlephZero

4 
788 
I am trying to prove that for any two vectors x,y in ##ℂ^{n}## the product ## \langle x,y \rangle = xAy^{*} ## is an...

Aug1613 08:41 PM
chiro

4 
833 
Hi all,
I would like to ask about the eigenvalues of adjacency matrices of a simple undirected unweighted graph. I...

Aug1613 03:53 PM
simpleton

0 
681 
Similar matrices share certain properties, such as the determinant, trace, eigenvalues, and characteristic polynomial....

Aug1613 11:50 AM
Office_Shredder

3 
1,086 
What is the sample mean of the following matrix?

Aug1413 01:45 PM
statdad

2 
724 
Hi
I am trying to learn how the number systems was created, and there are two very basic thing I don't get.
...

Aug1313 08:02 PM
bobby2k

7 
770 
\renewcommand{\vec}{\mathbf{#1}}
Here is an excerpt from the text:
"Theorem 12.5 The only finite symmetry groups...

Aug1313 09:02 AM
lpetrich

10 
1,238 
I have a problem with something that should be very simple,I do not no if it is programming issue or my ignorance.
If...

Aug1213 08:13 PM
HallsofIvy

3 
800 
I gather the modern term for a set with a closed binary operation is "magma" and that the old term "groupoid" now...

Aug1213 12:10 AM
Stephen Tashi

2 
662 
Hi all,
I would like to know if there exists any method to represent multidimensional vectors on a 2D plot so...

Aug1113 11:16 PM
dexterdev

8 
1,148 
This might seem like a stupid question but would the null space of a matrix and its, say Gaussian elimination...

Aug713 12:46 PM
HallsofIvy

2 
697 
I am following Friedberg's text and having some trouble understanding some of the theorems regarding...

Aug713 07:32 AM
HallsofIvy

3 
743 
This system originates from systems of linear Diff Eqs. I am required to use the method of undetermined coefficients....

Aug613 04:15 PM
SteamKing

7 
939 
Could someone please help me to read the following line(in case of inner product)?

Aug613 10:36 AM
jbunniii

3 
1,106 
I was wondering if anybody can see where I have gone wrong here?
I was given the rule, E2(E1A1)=(E2E1)A1, I can't...

Aug513 02:19 PM
AJBMuir

2 
750 
Its been a while since I've done this stuff, and I don't have a text handy. I know that for sets, intersection...

Aug513 01:20 PM
jbunniii

1 
735 
I have heard about two or above dimensional plane which we can express R2 or Rn. But I never heard about...

Aug513 12:51 PM
HallsofIvy

1 
596 
I need to convexify a 2D function
F:R ^2 > R
I have an analytic expression for F, but it is exceedingly...

Aug513 12:10 PM
brunnels

0 
593 
The matrix is an example of a Linear Transformation, because it takes one vector and turns it into another in a...

Aug513 03:17 AM
Fredrik

2 
635 
What is the difference between orthogonal transformation and linear transformation?

Aug513 01:01 AM
EnglsihLearner

6 
1,888 
When I start to read the the article called "symmetric bilinear forms", I face the following sentence. But I don't...

Aug413 11:49 PM
micromass

3 
571 
Let M be a module over the commutative ring K with unit 1. I want to prove that M \cong M \otimes K. Define \phi:M...

Aug313 08:42 PM
micromass

3 
1,075 
Do hyperbolic rotations of euclidian space and ordinary rotations of euclidian space form a group?

Aug313 12:18 AM
neerajareen

2 
520 
Hi,
I'm getting a bit confused about the adjoint representation. I learnt about Lie algrebras using the book by...

Aug213 03:24 PM
AlbertEi

0 
564 