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

Feb2313 09:24 AM
micromass

1 
35,127 
What interpretation could the eigenvectors in a graph have? By graph I mean an adjaceny matrix not counting...

Jun1311 08:11 PM
Ackbeet

1 
1,661 
What is the absolute best abstract algebra book for graduate students? I was wanting a book that covers algebra in the...

Jun1511 09:55 PM
ForMyThunder

5 
3,083 
Hi folks,
If I have a Lie algebra \mathfrak{g} with an invariant (under the adjoint action ad of the Lie algebra)...

Jun1411 11:50 AM
SergejVictorov

2 
1,382 
For any natural number a and b, with b > 1, two natural numbers x and y can always be found such that b^x  b^y is...

Jun1311 01:10 AM
marshmellow

5 
2,446 
I know that any prime p = 1 mod 4 can be expressed as sum of 2 squares.
But how many different pairs of integers a,b...

Jun1411 08:23 AM
robert Ihnot

7 
2,803 
Hi,
Is every matrix similar to a triangular matrix? If it is, anyone have an idea how to prove it?
Thanks

Jun1311 03:37 AM
td21

3 
1,286 
I'm trying to find out what the rotation group of a cube is. It seems natural to view it as a subgroup of S_{6},...

Jun1611 03:47 PM
lpetrich

18 
5,340 
With normal vectors i usually check there is the correct number of vectors i.e 3 for R3 2 for R2 etc and then just...

Jun1211 07:11 AM
HallsofIvy

10 
2,123 
Hi,
I have this problem,
1) Find 1 + 2 + · · · + n by summing the identity (m + 1)2 − m2 = 2m + 1 from m = 1 to...

Jun1211 10:31 PM
bluemoon2188

2 
1,851 
Suppose that the set of functions \{P^a:\mathcal S\rightarrow \mathcal L\,a\in \mathcal L\} has the property that for...

Jun1111 07:26 PM
Fredrik

2 
657 
does multiplying the invertible matrix A to the basis {X1,X2,X3..Xn} create a new basis; {AX1,AX2,Ax3..AXn}? where Xn...

Jun1311 02:48 AM
mitch_1211

4 
1,746 
i want to extend the set S={(1,1,0,0),(1,0,1,0)} to be a basis for R4. I know I am going to need 4 vectors, so i need...

Jun1811 04:07 PM
Bacle

6 
6,544 
Hey everyone,
Not sure if this is the right section to post this in, but makes the most sense to me so here goes.
...

Jun1111 10:52 PM
Xian

0 
1,215 
Hi, I'm currently doing a project and this topic has come up. Are there any known famous classes of polynomials...

Jun1211 01:18 PM
burritoloco

8 
1,279 
\lambda_i(AB)\leq\lambda_i(A)\lambda_i(B)?
\lambda_i(A+B)\leq\lambda_i(A)+\lambda_i(B)?...

Jun1311 02:10 AM
td21

0 
677 
I want to express the matrix product Ax as a linear combination of the column vectors in A.
I know for that for...

Jun1311 08:17 PM
Mark44

5 
5,117 
lets assume the matrix multiplication AB exists, how would i prove that the column space of AB is contained in the...

Jun1311 03:01 AM
td21

3 
4,206 
For two matrices A and B, when p(A)=0 iff p(B)=0 for any polynomial, what will happen? i read that A and B have the...

Jun1311 02:13 PM
HallsofIvy

2 
1,264 
Hi!
Q is postive definite
A is any matrix.
Why Q^{1}AQ^{1} is hermitian??

Jun1311 04:17 AM
dragonlorder

1 
644 
if i have a 4x3 matrix, this means there are more equations than unknowns and so there are no solutions to the system....

Jun1411 03:19 AM
td21

3 
2,564 
If S^{1}BS=A, can we always find Q ,such that Q^{1}BQ=A? Q different form S and no scalar multiple of S.
If not,...

Jun1311 05:54 AM
henry_m

1 
673 
Hi folks. This is something I've been wondering about for a while now. Is there a reason why taking the minimum norm...

Jun1311 10:23 AM
HallsofIvy

1 
825 
Hello all :)
I am studying divisibilities of
1, 11, 111, 1111, 11111 and so on
when I have even number of 1s, in...

Jun1311 08:46 PM
l1jcho

2 
1,540 
Hi, yet another question regarding polynomials :). Just curious about this.
Let f(x), g(x) be irreducible...

Jun1511 08:21 PM
burritoloco

5 
1,385 
In the book I am looking only one of the following is listed as a Jordan Form. Could somebody tell me why the other...

Jun1511 07:05 PM
Zorba

5 
1,130 
I have a nonhomogeneous Ax=b (with b nonzero) and i want to know if the set of all the solution vectors, x, forms a...

Jun1411 04:03 AM
td21

2 
2,295 
I came across this question. How do you show that √N is irrational when N is a nonsquare integer?
Cheers.

Jun1611 07:12 AM
bgwyh_88

2 
2,271 
I have a question I need to resolve before my exam on thursday. It relates to the following result:
Let N be a...

Jun1411 01:25 PM
Zorba

2 
1,145 
The prime number theorem describes the distribution of the prime numbers, in a sense. Are there other prime number...

Jun1511 08:12 PM
hansenscane

2 
1,792 
Hello :)
I have been giving a mathematical problem. But I find difficulties solving this. Therefore, I will be very...

Jun1611 08:21 AM
micromass

12 
2,215 
Consider the spectral decomposition , let
Gj=xjyjT for j=1,2,3 ,n so that A=sigma (mjGj) .
aShow that each...

Jun1511 11:11 AM
bernoli123

0 
839 
Show that the representation of T with respect to the basis {x1,x2,x3, xn} where xi belong toSi (1 less i less ...

Jun1511 11:13 AM
bernoli123

0 
776 
Consider a) f1=1, f2=sinx , f3=cosx
b) f1=1, f2=ex , f3=e2x
...

Jun1511 11:30 AM
micromass

1 
875 
If \omega is an alternating tensor, then Alt(\omega)=\omega, where Alt is the mapping that maps any tensor to an...

Jun1511 02:52 PM
Office_Shredder

1 
872 
Given two orthonormal bases v_1,v_2,\cdots,v_n and u_1,u_2,\cdots,u_n for a vector space V, we know the following...

Jun1711 01:44 AM
I like Serena

6 
1,546 
such as some 3D matrix visualization or eigenvalue/singular value things/jordan form?
Thanks very much for any...

Jun1811 10:01 AM
Stephen Tashi

1 
1,668 
Is saying \existsx, \existsy
the same as saying \existsy, \existsx?

Jun1711 10:54 PM
gmmstr827

2 
1,690 
If Riemann's Hypothesis is proved as true, would number theory collapse?

Jun1811 08:20 AM
Karlx

3 
1,772 
"orthonormal columns imply orthonormal rows for square matrix."
My proof is:
Q^{T}Q=I(orthonormal columns)...

Jun1811 03:53 AM
Fredrik

1 
940 
Hi all,
I have problem with regard to illconditioned linear system of solving sets of simultaneous equations using...

Jun1811 02:29 PM
kaizen.moto

0 
1,413 