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

Feb2313 09:24 AM
micromass

1 
30,523 
Hello,
I noticed that it is possible to define an inverse for the convolution operator so that a function f convolved...

Jul409 07:14 PM
trambolin

7 
9,543 
Can you help me with this problem:
if a^2 divides b^2, show that a divides b.
This was a homework question that I...

Oct2409 05:42 AM
Bingk

23 
9,520 
I am really confused on this topic.
can you give me an example and explain how you found, pleaseee!
for example,...

Jul2810 02:41 PM
Jamma

14 
9,518 
I am trying to find the Nth power of a general 2x2 real matrix. This seemed simple at first, but I am running into...

Dec2509 09:24 AM
Hurkyl

4 
9,496 
I need help proving the following:
1 A nonsquare matrix cannot have both a left and a right inverse
2 If a...

Nov407 01:18 PM
mathguy34

2 
9,458 
Hey,
I have a set of quadratic equations in the form of:
ax^2 bxy + cy^2 = d
ax^2 bxz + cz^2 = d
ay^2 byz +...

May1111 01:43 PM
hotvette

20 
9,444 
Let V be a vector space over the complex field.
If V has an inner product <\cdot,\cdot>, and \cdot is the...

May2110 02:12 PM
Landau

1 
9,420 
How can you show that an arbitrary n \times n matrix has n linearly independent eigenvectors? What if all you know...

May409 07:54 PM
jbunniii

3 
9,406 
Hi, has anyone else seen this news item http://www.physorg.com/news/201101maththeoriesrevealnature.html on how to...

Mar1711 05:26 PM
Raphie

12 
9,391 
Hello
I recall, I think, that there is a lemma wich states that a 2x2 symmetric matrix can be diagonalized so that...

Dec2811 06:52 AM
ApplePion

5 
9,361 
Hi,
I'm trying to solve the following matrix equation:
XAX' = B
where A,B are known...

Aug1105 03:21 PM
drorled

0 
9,350 
How is measure theory associated with number theory, if at all.
If they are connected, can anyone give a link?

Nov2107 04:02 PM
morphism

18 
9,347 
Someone please help me show that (uv)^n= Summation {u^(i)v^(ni)}
where i=0 the starting point and n is the ending...

Mar304 09:31 PM
Ed Quanta

18 
9,339 
Hi,
Is there a formula to do this? The textbook just says to "reverse" the action of T to get T^1 (T inverse). Can...

Jul1505 09:30 PM
KataKoniK

7 
9,329 
Do you think you could do vector operations in polar coordinates?

Oct2904 01:39 AM
James R

2 
9,325 
Wikipedia details the technique for converting from toroidal coords to cartesian. How do you convert the other way?
...

Feb2608 04:47 AM
pkleinod

22 
9,305 
Hi,
I recently became interested in some number theoretical questions. I have actually never really studied it...

Sep1108 09:08 PM
CRGreathouse

27 
9,285 
If A and B are idempotent(A=A^2) and AB=BA, prove that AB is idempotent.
this is what i got so far.
AB=BA...

Oct1507 03:02 PM
learningphysics

9 
9,281 
Is any formula that produces nth prime ?
if not visit this web site
http://www.primenumbersformula.com

Jul1808 11:49 PM
CRGreathouse

48 
9,264 
So I'm considering dimensions of real vector spaces.
I found myself thinking about the following:
So for the...

Mar408 10:54 PM
ircdan

1 
9,262 
I'm stuck on the following problem:
Describe the span of the vectors u1 and u2 in R^3, where
u1 = (1, 1, 1),...

Jun3005 11:05 PM
mathwonk

6 
9,260 
Hi,I am a Chinese sophomore major in software engineering.I am reading Artin's Algebrarecently and have come across...

Sep806 06:01 PM
GreenApple

6 
9,255 
I have the second printing of the first edition of Herstein's 'Topics in Algebra', published 1964.
On page 58 near...

Aug3008 01:05 PM
peter_n

6 
9,245 
Springer is having their annual Yellow Book sale and I was going to pick up an algebra text to supplement Dummitt and...

Oct1506 01:27 PM
mathwonk

7 
9,237 
Hello,
I am having trouble understanding groups in my group theory class. I am not confident on how to approach the...

Oct2903 06:38 PM
wubie

4 
9,226 
Hi there:)
I found a quick formula for calculate perfect numbers.
T(v)={{*}^2}/128  {*}/16
T(v1) is the...

Jun2707 09:34 PM
Kummer

9 
9,181 
I just have one question about the proof. Why does (p1)!a^{p1}=(p1)!\pmod{p}? It seems like it would be true if...

Sep1005 08:54 PM
amcavoy

5 
9,179 
hi
that day, a friends of mine asked me to find out the last digit of 3^999. i knew that i have to find out 3^999 mod...

Apr906 08:22 AM
murshid_islam

8 
9,173 
Hi,
I have forgotten the formula for calculating the second norm of matrix. Does anyone know the formula?
Regards,...

Sep1704 12:31 PM
mathwonk

2 
9,097 
We are currently using Dummit & Foote's Abstract Algebra book in a gradute course of the same name. Recently, I had...

Sep206 05:17 PM
AKG

9 
9,095 
Hi, this is my first post here, so bare with me.
So I need to compute the eigenvectors of a large matrix...

Jul1708 06:48 PM
JPRitchie

9 
9,048 
HI, I am taking linear algebra this semester, So i wanted to know..what does linear algebra deals with? Is it really...

Jan1406 04:28 PM
Kouros Khamoushi

17 
9,028 
Suppose we have a system of 2 equations in 2 unknowns x,y:
a1x+b1y=c1
a2x+b2y=c2
If the determinant of
is...

Sep2009 01:46 AM
kingwinner

1 
9,020 
Alright. As stated in the title above.
So, a subspace is a set of vectors that satisfies:
1) It contained the zero...

Mar809 04:24 PM
HallsofIvy

8 
8,996 
is the gcd of two successive integers (n, n+1) always equal to 1? i.e., are two successive integers always coprime? it...

Mar1507 10:03 AM
Moo Of Doom

8 
8,993 
I do not know if this counts as number theory, but I came to this question while studying number theory, so I post...

Mar1108 01:29 PM
LorenzoMath

11 
8,969 
Hi! I'm in serious need of some help.
I am supposed to show that a transformation \mathcal{A} = \mathbb{R}^n...

Jan3104 08:00 AM
matt grime

1 
8,911 
How do i comput the euler phi function of a large interger?
i know that if p is prime then phi(p)=p1 and i've found...

Jun2509 03:44 AM
Petter

5 
8,904 
I'm not saying PF is a bad forum....but
*What are some good books on number theory?
I'm a HS senior, currently...

Nov1105 07:10 PM
mathwonk

4 
8,901 
I'm reading through the book "Linear Algebra", by Jim Hefferon (which you can download for free!). In section I.3, he...

Apr2005 05:45 PM
HallsofIvy

2 
8,892 