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

Feb2313 09:24 AM
micromass

1 
35,192 
Let S be a set on which a linear order <= (less or equal) , is defined. Show that a nonempty finite subset has a max.

Apr2810 05:17 AM
Martin Rattigan

3 
839 
Let a,b>1 be integers such that for all n>0 we have a^n1b^n1. Then b is a natural power of a. I can't find a...

Apr2810 04:57 AM
Martin Rattigan

31 
3,626 
Hi, everyone.
I have a question about geometric constructible numbers.
I know that "if 'a' is constructible then...

Apr2710 07:37 PM
emptyboat

2 
926 
for a 3 x 3 matric of values
a11 a12 a13
b21 b22 b23
c31 c32 c33
the determinant will be...

Apr2710 01:29 PM
Fredrik

1 
1,918 
As a generalization to some problem I've just seen, I'm wonder what the solution to the following question is:
For...

Apr2710 01:01 PM
Martin Rattigan

21 
3,492 
hi, i don't really understand whats the difference between vector product and dot product in matrix form.
for...

Apr2710 11:42 AM
quietrain

6 
10,137 
Let R be an ordered Ring. Assume R+ is wellordered
Prove:
a) min(R+) = 1.
b) R is an integer ring

Apr2710 09:04 AM
g_edgar

2 
775 
Hello, I'm a senior mechanical engineering student.
I'm trying to write an application that plots the system...

Apr2710 04:05 AM
trambolin

14 
5,230 
Hi,
is there any numerical invariant that would characterize the rank of a nonsquare matrix, similar to the...

Apr2710 04:03 AM
trambolin

5 
5,166 
I need to prove the following.
1. A is a symmetric matrix, and x(transpose)*A*x=0 for all x (belongs to R^n) if and...

Apr2710 03:55 AM
trambolin

2 
1,039 
(Note: this isn't a homework question, I'm reviewing and I think the textbook is wrong.)
I'm working through the...

Apr2610 05:04 PM
Dosmascerveza

8 
6,022 
http://img710.imageshack.us/img710/2314/booleanalgebra.jpg
AFAIK logic is all about "T"/"F" or 0/1, and boolean...

Apr2610 02:14 PM
TacTics

3 
1,003 
I need to compute the 3 eigenvalues and 3 eigenvectors of a symmetric 3x3 matrix, namely a stress tensor,...

Apr2610 01:05 PM
jrosen13

8 
14,890 
Let R be a noncommutative ring . Suppose that the number of nonunits of R is finite . Can we say that R is a finite...

Apr2610 10:54 AM
zhentil

5 
1,349 
Claim: If gcd(a,b,c)lcm(a,b,c) = abc, then gcd(a,b)=gcd(b,c)=gcd(a,c)=1.
I'm trying to understand why this is...

Apr2510 04:49 PM
disregardthat

6 
5,116 
hi guys, i have no idea of how to do the following question, could u give some ideas?
Q:determine whether or not...

Apr2510 10:59 AM
HallsofIvy

7 
3,550 
Let me put this here, as it's so simple that everyone can take a look at it. I must be blind not to see my...

Apr2510 04:45 AM
ManDay

0 
1,008 
how do I find all u in R such that Q(u)=Q(√2,³ √5 ) (square root of two and cubed root of 5) and prove they are the...

Apr2410 07:07 PM
VKint

1 
1,187 
Lets try arguing in not mathematical terms but logical reasoning. if a number x is divided by any number n, it means...

Apr2310 06:21 AM
Mentallic

16 
3,367 
I am trying to find an example of a diagonal linear operator T in L(H) H is hilbert space that is bounded but not...

Apr2210 03:50 PM
Landau

1 
1,406 
Show that if a \equiv b mod p for all primes p, then a = b.

Apr2210 09:00 AM
HallsofIvy

5 
4,745 
I am having difficulties with understanding some aspects of inner products. For example,
u² = <u,u>
Where...

Apr2210 08:45 AM
HallsofIvy

10 
1,881 
Hi!
Studying the introductory chapters of a Operator Theory book, I have found that the author seem to find a lot of...

Apr2110 09:18 PM
JSuarez

5 
1,295 
For the theorem: " If v1,.....,vr are eigenvectors of a linear map T going from vector space V to V, with respect to...

Apr2110 08:31 AM
HallsofIvy

6 
2,352 
One of the topics in my linear algebra course is kernel and range of a linear transformation. I have a firm...

Apr2110 12:55 AM
radou

3 
1,404 
Can someone explain to me how to find all the cosets of a set like H={A in GL(n)  det(A) = 1} in GL(n) (set of...

Apr2010 01:21 PM
Martin Rattigan

6 
3,418 
Let R = Mn(F) be the ring consists of all n*n matrices over a field F and
E = E11 + E22 + ... + En1,n1, where Eii...

Apr2010 01:01 PM
Martin Rattigan

4 
1,113 
Does anyone have a good resource of worked examples on simple (ish) tensor algebra? By way of background I'm a...

Apr1910 05:42 AM
bill nye scienceguy!

2 
1,465 
Why is it that if the sum of the digits of a number is divisible by three, the number itself is also divisible by...

Apr1910 02:16 AM
Char. Limit

5 
2,773 
Hi all,
Let's say we have a symmetric matrix A with its corresponding diagonal matrix D. If A has only 1...

Apr1810 02:20 AM
Noxide

4 
5,334 
Hi
I am struggling to get my head fully around the conjugacy classes of D5.
Everywhere I have looked seems to...

Apr1710 01:27 PM
Martin Rattigan

5 
8,843 
Is there a variant form of induction to prove something about the rationals as opposed to just the natural numbers?
...

Apr1710 12:24 PM
ramsey2879

2 
1,561 
This is a theorem about Jacobi symbols in my textbook:
Let n and m be ODD and positive. Then (a/nm)=(a/n)(a/m) and...

Apr1710 12:10 PM
robert Ihnot

1 
2,696 
Let x and y be elements of a group.
I can see that it works the other way, i.e. if x and y commute, then y*x^n =...

Apr1610 09:54 PM
landor

5 
1,677 
Amateur question ahead, be warned.
I really dislike proofs that something cannot be done. My first gripe is that...

Apr1510 10:35 PM
CRGreathouse

18 
10,691 
I think I have worked out a formula for Prime Numbers. I said, "I think," because
1. I dont know , Is that formula...

Apr1510 12:30 PM
CRGreathouse

7 
1,718 
Is set theory, counting off members, realy indicative of any order of difference when neither set has a 'size' ? If my...

Apr1510 08:39 AM
lavinia

14 
2,079 
Today I was reading in a probabilities textbook that the probability of the union of two events is:
p(E_1 \cup...

Apr1410 03:22 PM
Damidami

0 
1,230 
I randomly came accross this problem:
http://en.wikipedia.org/wiki/Thirtysix_officers_problem
however, the...

Apr1410 02:33 PM
Martin Rattigan

1 
2,104 
Hi, can anyone explain to me if a 3 x 4 matrix can have independent columns? How about independent rows?
Thanks!

Apr1310 05:52 PM
VeeEight

3 
1,627 