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

Feb2313 09:24 AM
micromass

1 
35,782 
When I was in grade school my father told me about a method of checking my addition when I added columns of numbers. ...

Nov2111 04:09 PM
epsi00

4 
2,179 
My question is really simple, but I just have to get it confirmed:
for a matrix A, if det(A)=0 that means A has no...

Nov2111 12:17 PM
mathwonk

6 
2,245 
I am working on classifying all groups of order less than or equal to 100. For most orders, this is fairly...

Nov2111 11:14 AM
jgens

0 
889 
This book says that if W^aX_a=0 and X_a is arbitrary, then I should be able to prove that W^a=0. I don't see how this...

Nov2111 06:59 AM
HallsofIvy

2 
1,388 
I've formulated the game Flip It(http://www.coolmathgames.com/0flipit/index.html) into mathematical terms and a...

Nov2011 02:37 PM
TylerH

1 
1,612 
An augmented matrix scaled by a number also means the solutions set is scaled by that same number. I believe this is...

Nov2011 02:27 AM
Deveno

2 
1,032 
because the only thing the definition asks to check is the closure and inverse axioms?
this arose from a problem I...

Nov2011 12:22 AM
Deveno

4 
1,148 
why arent non continuous functions in an interval a linear space?

Nov1911 08:23 AM
HallsofIvy

9 
1,247 
tan(x)=k\frac{x}{z^{2}}
where k is the constant of proportionality, y varies according to x and z. x and z are...

Nov1911 08:21 AM
HallsofIvy

3 
1,064 
If p is prime and (a, p) = 1, show that x^2 \cong a (mod p) has solutions if a^{\frac{p1}{2}} \cong 1 (mod p) and...

Nov1911 06:19 AM
pedja

5 
2,715 
Hi, not sure if this is the right forum.. pls move if not.
Almost 30 years ago, I was studying engineering and my...

Nov1811 05:54 PM
narrator

6 
2,579 
how can we show that proj(a+b) = proj a + proj b on an arbitrary line. My book has a proof but it assumes that the...

Nov1811 12:24 AM
batballbat

0 
858 
I have to prove:
Consider V=F^{n}. Let \mathbf{v}\in V/\{e_{1},e_{2},...,e_{n}\}. Prove...

Nov1711 07:54 PM
Deveno

2 
1,202 
I am looking to find an arbitrary digit of lets say 23^234. This one has 219 digits. so lets find the 187th digit.... ...

Nov1711 07:50 PM
cap.r

2 
2,254 
This sieve is similar to the Sieve of Eratosthenes but is very different in its implementation. Instead of considering...

Nov1711 07:46 PM
idiom

23 
6,613 
I'm trying to find a general formula for an algebraic equation, I'm studying the behavior of...

Nov1711 07:43 PM
micromass

2 
2,655 
If R is a finite ring and its additive group is cyclic, then
R = <r> = {nr : n an integer} for some r in R.
r^2 is...

Nov1711 05:50 PM
Deveno

1 
1,083 
Restrict attention to vectors in ℝ^m where m is a natural number.
Let σ be the vector of ones. Let V be the set of...

Nov1711 05:35 PM
Deveno

13 
2,058 
I think a best informal way to state the theorem is Hardy's:
every positive integer (except the number 1) can be...

Nov1711 11:47 AM
julypraise

4 
2,543 
Can you calculate eigenvalues and eigenvectors for rotation matrices the same way you would for a regular matrix?
...

Nov1611 08:39 PM
chiro

5 
2,045 
Please note: Below, I keep trying to put but it gets turned into !!
In Dennery and Krzywicki, they give an...

Nov1611 05:56 PM
lurflurf

4 
1,428 
So I just want to give a little background. I'm Chandler Baker and love all there is to life: philosophy, etc... I...

Nov1611 05:35 PM
lostcauses10x

1 
1,646 
Is there a way within reasonable errors to say what part of the positive integers are prime and what part is factored...

Nov1611 05:29 PM
lostcauses10x

3 
2,237 
Say I have (a+b+c)^n and I want to split it apart into a^something + b^something + c^something. Is this easily done?

Nov1611 02:45 PM
mathman

1 
1,779 
As we know grad F (F surface) is in normal direction. But we also have (grad F(r)) x r = F'(r) (r) x r = 0
this...

Nov1611 10:10 AM
seshikanth

3 
1,073 
I have to prove:
Let u_{1} and u_{2} be nonzero vectors in vector space U. Show that {u_{1},u_{2}} is linearly...

Nov1611 07:56 AM
Deveno

10 
2,429 
Hi guys,
I always wanted to know if one could generate prime numbers according to an equation,so I wanted to go and...

Nov1611 07:18 AM
lostcauses10x

21 
5,730 
Having worked on prime ideals recently and finding them for Z_n I was wondering how you can to find all the prime...

Nov1511 03:52 PM
Deveno

1 
1,774 
Divisor summatory function is a function that is a sum over the divisor function. It can be visualized as the count of...

Nov1511 09:05 AM
JeremyEbert

18 
7,485 
Hi everyone.
My first post on this great forum, keep up all the good ideas.
Apologies if this is in the wrong...

Nov1511 05:18 AM
pwsnafu

1 
1,770 
I have read at a lot of places that in 2D transformations rotation is a combination of scaling and simultaneous shear?...

Nov1511 04:18 AM
Deveno

3 
2,865 
Which of the transformations are onto?
1) T:R2 > R2, where T(x,y) = (5xy, 0)
I don't know if I'm understanding...

Nov1511 03:47 AM
Deveno

1 
1,504 
Let Fn = 22n + 1 be the nth Fermat number and suppose that pFn, where p is a prime (possibly Fn itself). Show that ...

Nov1411 10:25 PM
demonelite123

4 
2,087 
If we take the derivative of n functions that are linearly independent to each other and we write it down like c1f1(x)...

Nov1411 03:30 PM
AdrianZ

8 
2,241 
Hi guys,
I have a bit of a strange problem. I had to prove that the space of symmetric matrices is a vector space....

Nov1411 02:12 PM
Rowina

0 
938 
Do tuples exist which aren't elements of a cartesian product of sets?
Can you just write an ordered list of elements...

Nov1411 09:18 AM
eztum

3 
1,431 
This is more of a conceptual question more than anything. I've never done any financial modelling, let alone modelling...

Nov1211 10:32 PM
Stephen Tashi

1 
3,005 
I have an equation:
tr\left\{\textbf{AB}\right\} = \sigma
where tr\left\{\right\} denotes the matrix trace. The...

Nov1211 02:56 PM
weetabixharry

5 
1,518 
Hello. First, I'd like to apologize because I don't know where to go ask for homework on linear algebra on the forums...

Nov1211 09:21 AM
sam0617

6 
6,189 
Hi, I wonder that is there any way to disassemble this operation ((n+2^(n2))^2 mod 1000000007) without counting...

Nov1211 07:47 AM
I like Serena

15 
3,919 