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

Feb2313 09:24 AM
micromass

1 
35,751 
A little while ago I noticed a pattern in the sums of the digits of perfect squares that seems to suggest that:
For...

Apr1204 08:55 PM
honestrosewater

25 
7,431 
My lack of any shred of idea about the concept of the determinant is really beginning to bug me. Especially now that I...

Sep2010 12:09 PM
mathwonk

23 
7,397 
I am a member of the Dozenal Society of Great Britain ( www.dsgb.orbix.co.uk ) . We maintain that base twelve is...

Jan1410 03:17 PM
HallsofIvy

34 
7,396 
I'm working on a skeletal animation system, and I want to interpolate the rotations between frames. The rotations are...

Jan2705 04:42 PM
BobG

2 
7,394 
About 20 years ago I caught an article about a graduate student
who had found an algoritm which would return the nth...

Sep2706 07:55 PM
Mothershed

14 
7,381 
Hi,
This is the problem:
Lorraine has $7.70 in dimes and quarters. If the number of quarters is two more than twice...

Apr3005 10:30 PM
dajohu

2 
7,379 
Can isomorphism of matrix groups
\phi: G_1 \rightarrow G_2
always be expressed by
\phi(M) = S M S^{1}?

Jul2508 03:43 AM
cathalcummins

16 
7,368 
I have to prove that if ab is divisible by the prime p, and a is not divisible by p, then b is divisible by p.
In...

Aug604 08:10 AM
HallsofIvy

9 
7,359 
Can someone guide me through the proof (or point me to where I can find the proof) that the group of rational numbers...

Apr2904 12:46 PM
NateTG

7 
7,354 
How to find detA if A is 4x4 matrix or more than 4x4.

Oct2910 12:01 AM
mathwonk

7 
7,335 
hello all
after doing a bit of research on the riemann hypothesis I came along this paragraph, in which I dont...

Dec1010 01:37 PM
change257

16 
7,317 
Investigating the Diophantine equation q = \frac{n^2+1}{p}} where {p} is a prime number, n,q are integers per...

May1805 07:56 AM
AntonVrba

5 
7,312 
Hi,
I have been searching the web for this subject to see if the formula I stumbled on
is out there. This site...

Jun1308 05:58 AM
jim mcnamara

1 
7,308 
I am reading (theorem 2.14) from a textbook, and don't understand how g = Tf and (#1) line of reasoning. The theorem...

Oct1909 11:08 AM
viviane363

9 
7,306 
I've done 3 of my 5 problems, which took me 2 days and over 3050 pieces of scrap paper. I'm serious, I didn't even...

Oct505 12:16 AM
ramsey2879

6 
7,288 
I am trying to find a way to generate solutions to 5b^2*c^2 = 4a^2(b^2+c^2)
Can anyone offer some insight?
I...

Dec1312 06:26 AM
ramsey2879

55 
7,283 
Greetings, I just stumbled upon this site and thought someone might be able to help me. How many elements of order 5...

Oct604 11:22 AM
Motifs

2 
7,261 
I have this matrix problem:
Given R_1, R_2, R_3\in\mathbb{R}^{N\times N} are symmetric matrices with rank p<N....

May2306 07:36 AM
doodle

1 
7,259 
Hello,
can anyone tell me if I understand this right? :rolleyes:
I have a tinvariant subspace with basis B,...

Feb1407 11:08 AM
matt grime

3 
7,257 
Q: If A is an m x n matrix and rank A = m, show that m <= n.
I know that by definition if A is m x n, then rank A...

Jul1305 10:46 PM
mathwonk

9 
7,252 
I mean, according to my knowledge, Bertrand's postulate has already been proved, I've already read and understood one,...

Apr3010 04:11 AM
astroultraman

20 
7,246 
I'm looking at the exercises of Hungerfod's Algebra. Some looks easy but it seems the proofs are not so obvious....

Nov1109 12:27 AM
Spartan Math

4 
7,244 
I need to find the inverse of a 2x2 matrix of the form
I'm halfway there, but the algebra gets really messy. ...

Sep2408 09:51 PM
Defennder

3 
7,241 
Cantor's diagonal slash has been used to argue that the infinity of reals is uncountable, whereas the infinity of...

Mar705 05:23 AM
Hurkyl

44 
7,227 
hmm.........

Sep3011 05:47 PM
lostcauses10x

19 
7,222 
Quick question: is the nullspace the orthogonal complement of the column space or the the row space?
Thanks, sorry...

Nov2204 05:21 AM
Galileo

2 
7,211 
Just a conjecture...
If any realizable real is built from the integers, then the single smallest positive real is:...

Jun2104 01:22 AM
Jack Martinelli

16 
7,183 
Does anybody know of any jobs that deal explicitly with Matrices and/or Linear Algebra? I have to do a paper and I...

Oct1907 12:43 PM
chapani

2 
7,177 
Claim: n! + 1 and (n+1)! + 1 are relatively prime.
How can we prove this? Can we use mathematical induction?
Base...

Jan1410 01:09 AM
Ivan,Cow'sSon

45 
7,160 
write all possible equivalent conditions to "A is invertible," where A is an nxn matrix.

Nov707 07:55 PM
morphism

7 
7,154 
A function f between groups is said to be a homomorphism if it "preserves" the product in the sense that...

Aug210 05:58 AM
Fredrik

52 
7,142 
I'm working on some basic number theory. I came across an idea and I'm having trouble finding a general solution.
A...

Jun2807 11:08 AM
ramsey2879

3 
7,131 
If you have two groups, G_1 and G_2 and A is a common subgroup, then you can form the free product of G_1 and G_2...

Oct2506 10:30 PM
mathwonk

20 
7,107 
I've been told that any number raised to the zeroeth power is equal to 1. What about zero raised to the zeroeth...

May2905 09:06 AM
matt grime

83 
7,106 
The question:
If G is the additive group Q/Z, what are the elements of the subgroup G(2)? Of G(P) for any positive...

Sep1208 01:50 AM
morphism

1 
7,093 
I have a few questions to ask. They are simple, but the purpose is to make sure I'm staying on track.
First, the...

Jan2606 05:20 PM
JasonRox

44 
7,089 
How would I calculate the determinant of a square matrix using LU Decomposition. Please be plain, I am not good with...

Aug2009 10:11 PM
jeff1evesque

1 
7,071 
What do you guys think of this? I haven't been able to find any sort of verification from reputable sites.
"Edgar...

Oct606 12:08 PM
arildno

20 
7,062 
So I've shown that A and A^T have the same char. polynomials => same eigenvalues, using the fact that detA = detA^T. ...

Feb1508 04:19 PM
ObsessiveMathsFreak

2 
7,062 
Hi
I don't understand why only a matrix full of zero has a rank = 0.
"the rank of a matrix A is the number of...

Mar2711 12:32 PM
eg0

5 
7,046 