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

Feb2313 09:24 AM
micromass

1 
35,119 
X^3+PX+Q=0
X_0 = A + B
(A+B)^3 + P(A+B) + Q = 0
A^3 + B^3 + (3AB+P)(A+B) + Q = 0
The next step is 3AB+P=0

Oct1710 12:39 AM
kennysmith39

3 
3,009 
I just started reading the first chapter of Georgi Shilov's "Linear Algebra" and I have a question about his notation...

Nov2810 04:57 PM
RBNYC2

3 
2,825 
Hi,
Is there a simplification for the determinant of a symmetric matrix? For example, I need to find the roots of ...

Dec1810 04:08 PM
yiorgos

3 
5,029 
Definition: A semigroup is a pair (R,op) where R is a set an op is a binary operation that is closed and associative. ...

Sep810 06:27 AM
Eynstone

3 
1,262 
0, 1, 1, 1, 2, 2, 4, 8, 12, 96...
What number follows?

Sep510 03:11 AM
adriank

3 
1,029 
Are there cases where there's more than one binary operation to choose from by which to define a Lie algebra for a...

Sep1010 10:47 PM
Rasalhague

3 
975 
what will be the sum of this series?
\Sigma nCr . 2r
where r = 0 to n

Sep1510 02:22 AM
Sherard

3 
1,160 
Appoint all the pairs (k, l) (both k and l in R^+) such that:
\sqrt{k}+\sqrt{l}=\sqrt{4+\sqrt{7}}
I'm really stuck...

Sep1210 09:44 PM
adriank

3 
1,050 
I was wondering what would be the largest possible value for a determinant, for a 3 by 3 matrix whose entries can only...

Oct1110 06:42 PM
Simon_Tyler

3 
4,229 
I'm reading the first chapters of "A Guide to Distribution Theory and Fourier Transforms".
On page 10, Exercises...

Sep1910 01:21 PM
Goldbeetle

3 
967 
what is another way to form (a+b)^c to another simple expression?
like for example a^c+b^c doesnt work because its...

Sep2010 10:12 PM
GlobalDuty

3 
1,153 
When I realize that I am going to have a singular matrix (after exhausting row swap options and maybe even some...

Sep2210 09:50 PM
MurdocJensen

3 
12,166 
Here is my problem. Any ideas are appreciated.
Let P be a projection matrix (symmetric, idempotent, positive...

Sep3010 06:28 AM
trambolin

3 
6,811 
not hw question and i say yes.

Oct2810 03:52 PM
Outlined

3 
857 
I read the following on the wikipedia page about simple rings (http://en.wikipedia.org/wiki/Simple_ring):
I do...

Oct310 10:32 PM
gerben

3 
1,103 
Sounds great thank you

Oct310 04:28 PM
Simon_Tyler

3 
1,141 
Hello everyone. I was going through my Linear Algebra Done Right textbook that threw me off. I hope this forum is...

Oct410 11:17 PM
adriank

3 
5,067 
Is it true that if a finite group G contains a subgroup of index 2, then there is an element of G with order 2?

Oct810 10:08 AM
ForMyThunder

3 
816 
I saw the following problem on my abstract algebra book (dummit && foote) , I tried to solve it but I couldn't :
Let...

Oct1110 04:03 AM
hermanni

3 
1,728 
Let V be a finitedimensional vector space over the field F and let T be a linear operator on V. Let c be a scalar and...

Oct1210 12:49 PM
arkajad

3 
1,563 
Do all linearly dependent sets have elements that are linear combinations of each other? Or does this apply only to...

Oct1210 10:21 AM
ichigo444

3 
1,045 
Can i use the invertability of a matrix as an alternative way of determining the linear independence of a set? Thank...

Oct1210 10:54 AM
Wizlem

3 
919 
I expanded (x+y),(x+y) and got x^2+y^2 > 2xy then replaced 2xy with 2x,y but now I'm stuck.
I need to get it to...

Oct1510 10:14 AM
Rederick

3 
4,741 
Suppose I have three vectors a,b and c in R^d , And, I have that a.b < c.b(assume Euclidean inner product). What are...

Dec710 05:19 PM
Edgardo

3 
1,097 
I think I understand most of this Wikipedia page on the interior product ("not to be confused with inner product"):
...

Oct1710 02:01 PM
Rasalhague

3 
1,943 
Since my late interests have been related to networks, I've started a pet project focusing on natural numbers network....

Oct2110 03:27 AM
networks

3 
1,595 
Hey there, physics forums!
A question occurred to me the other day: Is it true that if f \in \mathbb{Z} is monic...

Oct2110 05:26 PM
CRGreathouse

3 
1,436 
We have vectors x,y of size n and a matrix A of size nxn.
Is it true that the matrix xyTA has at most one non zero...

Nov410 09:27 AM
Outlined

3 
1,496 
Prove that the collection F(N) of all finite subsets of N (natural numbers) is countable.

Oct2810 05:05 PM
willem2

3 
2,134 
Hi,
I ran into conflicting definitions of integral domain. Herstein defines a ring where existence of unity for...

Nov710 04:10 PM
mathwonk

3 
1,406 
I was wondering, if we want to define a morphism from
\mathbb{Z}2006 to, lets say \mathbb{Z}3008.
Obviously, all...

Nov710 04:48 PM
Outlined

3 
1,176 
Im struggling to find proof for this suspicion I have;
Given is a function f(t) and a normalised function h(t), and...

Nov2410 10:22 AM
gerben

3 
1,716 
Question: Show that if R is an integral domain then R^x=R^x(or that the units in R are precisely the units in R, but...

Nov1910 08:49 AM
mathwonk

3 
2,198 
Some one please help me how to prove the following:
\dot{A}:B + A:\dot{B}=A^{\nabla J}:B+A:B^{\nabla J}
A and B...

Nov2110 03:55 PM
josh_machine

3 
3,450 
Hi, I read that the general form of an inner product on \mathbf{C}^n is:
\langle \vec{x} , \vec{y} \rangle =...

Nov2210 08:38 AM
andresordonez

3 
2,178 
How to proof that equation?
a^m \equiv a^{m\phi(m)} mod m ?

Jan1211 08:01 AM
oszust001

3 
1,257 
No. This isn't homework. And I think I am right there with this one.
I'm interested in the intersection of groups...

Dec1410 10:45 PM
kamil9876

3 
912 
Hello
I'm trying to proof the following: f is a semilinear transformation between the vectorspaces V \rightarrow...

Dec1810 10:27 AM
ilia1987

3 
1,327 
Hello everybody,
To compute an observable in a physical problem I need to compute the determinant of a skew matrix...

Jan711 04:15 PM
AlephZero

3 
3,893 
Where, on the internet, can one learn the method to solving equations modulus a number? I'd like to learn the method...

Jan1011 11:54 PM
robert Ihnot

3 
1,903 