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

Feb2313 09:24 AM
micromass

1 
35,870 
I have been asked to show that in Sn the cycle (1,2,....n) only commutes with its powers.
I know that cycles commute...

Jan512 06:19 PM
micromass

8 
3,239 
Hi, Algebraists:
The modN reduction map r(N) from a matrix group (any group in which the elements
are matrices...

Dec3011 12:58 AM
Bacle2

2 
1,563 
Hi, I can do Dijkstra's Algorithm alright, but I always have problems with questions which have some relevance to the...

Jan212 06:01 AM
Ineedhelp

4 
4,156 
I am wondering what are the possible homomorphisms
\tau : Z\overline{+} > Z\overline{+}
From this it should be...

Dec2811 12:21 PM
spamiam

2 
2,035 
I need some help with understanding the basics of Lie algebra theory. I suspect my problems are due to a fundamental...

Jan412 04:57 AM
naima

1 
1,141 
I'm curious, can anyone think of a way to prove whether or not p^x  d^y = p  d, for any odd primes p,d and natural...

Dec3011 01:27 PM
omalleyt

3 
2,407 
Hi,
I am wondering if all isomorphisms between hilbert spaces are also isometries, that is, norm preserving. In...

Dec2811 09:38 AM
Hawkeye18

17 
3,117 
Affine Transformation Matrix is said to be formed by initializing it using a learned projection matrix from a...

Jan312 08:43 PM
Avinash Raj

2 
1,442 
I was thinking about some similarities in the definitions of group and field, and if it would be possible to...

Dec2811 01:49 PM
Damidami

8 
1,751 
According to theory the eigenvalues of a completely disconnected graph (no two nodes are connected) must be all 0. But...

Dec2811 09:00 AM
I like Serena

8 
1,636 
I'm trying to prove the following, which is left unproven in something I'm reading on rulerandcompass constructions:...

Dec2811 06:25 PM
micromass

3 
1,368 
Hi,
I want to solve the following equation by x:
Ʃ(ai^x b)^2 = C ,
where Ʃ is over all i, i = 1:N, and ^...

Jan412 01:12 PM
alexfloo

7 
1,614 
Can someone please add more detail or give references to help explain the lines of math in "Riemann's Zeta Function"...

Jan112 08:06 AM
SychoScribler

2 
3,030 
I was struck with the following question: Is there a linear map that's injective, but not surjective? I know full well...

Dec2911 12:35 PM
Fredrik

4 
2,431 
I know from linear algebra that you can take two things, and if they are equal to each other then you can simply...

Jan212 03:05 PM
NanoPassion

7 
1,569 
Hi,
I'm studying my algebra and I was trying this exercise:
Solve
z³+iz²7ziz66i=0
I found the 2 real...

Jan212 09:42 AM
yoyoyo992

2 
1,483 
The determinant of a matrix is given by the wellknown formula
det(A) = sump parity(p) * producti = 1...n Ai,p(i)
...

Jan712 11:02 AM
lpetrich

2 
1,269 
Does this concept exist? Google yields weird results that mostly have to do with programming, and Wikipedia says...

Dec3111 02:14 PM
marschmellow

0 
2,211 
I have no trouble calculating eigenvalues but I have a hard time understanding how to use them. I know that you can...

Jan212 10:02 AM
AlephZero

2 
4,967 
Hi!
Given a matrix A of elements A_i\;^j, which is the right transpose:
A_j\;^i
or
A^j\;_i
?

Jan512 02:51 PM
qbert

4 
1,141 
I like to know
what is best known efficient algorithm to calculate f(x)modg(x) , in which the degrees of f(x) and...

Jan1012 06:34 PM
Stephen Tashi

1 
1,854 
I've had a go at trying to come up with a procedure, for the following, but not making much progress.
I've googled...

Jan612 06:47 PM
dev00790

0 
1,124 
I'm just revising my maths notes on matrices and I have a couple of questions, mainly about representation of...

Jan312 04:31 PM
rollcast

2 
1,435 
I've been beating my head against this problem for hours. I see numerically that two expressions are equal, but I...

Jan412 04:37 AM
Fredrik

3 
1,081 
Hello,
I was going through the same problem. From what I can see on the net, one of the relations a linear function...

Jan412 04:26 PM
wisvuze

1 
942 
Say I have the equation a^2  10b^2 = 2. So even though this is an equation in two variables and not one, I can still...

Jan612 06:58 PM
TylerH

5 
2,735 
I am using the Law of Cosines to extract and angle I need from a shaft that is turning on an air engine by piston...

Jan412 10:59 PM
Simon Bridge

3 
1,741 
if f(x)modg(x) is valid(means , if it yield a remainder) then , can there be negative powers of x in f(x)?
for...

Jan512 10:32 PM
ramsey2879

1 
1,872 
Well I don't understand this equality:
A^{j}_{i}*A_{j}^{k}=\delta_{i}^{k}
It is true because it is the result of...

Jan512 12:40 PM
Fredrik

10 
1,338 
The prime numbers are the multiplicative building blocks of the integers. Even so, their distribution escapes all...

Jan812 04:04 AM
dodo

14 
3,111 
Hello
I'm trying to show that the following upper bound on the matrix 2norm is true:
...

Jan1212 06:31 AM
Hawkeye18

3 
2,146 
So I need to calculate the square root of the covariance matrix \sqrt{\Sigma_tR\Sigma_t} (the matrix square root, not...

Jan1112 12:43 PM
Stephen Tashi

2 
1,840 
Are there any numbers that is not considered to be a subset of a complex number subset of
a + bi
Where a and b...

Jan912 07:55 PM
ohwilleke

3 
1,785 
Recently I was assigned to implement a procedure involving "3D projections" to "2D space". Supposing that 3D data is...

Jan1112 03:38 AM
chiro

4 
2,781 
Let A denote an mxn matrix and let A' denote the row echelon form of it, which has d steps. We then have according to...

Jan1012 02:36 PM
mathwonk

3 
1,125 
Hi, I have been representing complex numbers in graphical form in school recently. My teacher was telling me about a...

Jan1112 02:59 AM
chiro

1 
1,169 
I'm preparing for a qualifying exam and this problem came up on a previous qual:
Let A and B be nxn matrices. Show...

Jan1112 04:07 PM
morphism

5 
2,560 
how does one evaluate the direct product between a group G with components that are say 2tuple and a group H with...

Jan1112 09:22 AM
wisvuze

2 
1,133 
What is the operator inside the Connes' approach to RH ??, he gave a trace but never says what operator is or gives or...

Jan1212 08:29 AM
zetafunction

0 
1,211 
My apologies if this is in the wrong section.... I wasn't quite sure where to put it.
If we have the "Hessian of a...

Jan1212 10:49 AM
brydustin

0 
909 