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

Feb2313 09:25 AM
micromass

1 
30,988 
Working on another problem here with varying results. I have three line segments in 3D and am looking to find what...

Jul2112 08:53 PM
chiro

1 
1,104 
Hi All,
I am currently reading Menzel's "Mathematical Physics" and one part in particular confuses me. When he is...

Jul2012 05:28 PM
cpsinkule

7 
1,709 
There is an Exercise in a book as following :
Given a Manifold M , if N is a submanifold , an V is open set then...

Jul2012 12:17 AM
Bacle2

2 
1,251 
I'm interested in the crossover of Lie groups/differential geometry and I'm a bit confused about the relation of Lie...

Jul1712 05:21 AM
TrickyDicky

5 
1,709 
Hi everyone,
I am having a little trouble with the difference between a covariant vector and contravariant vector. ...

Jul1612 04:36 PM
Matterwave

1 
1,458 
Hi,
I am not very strong in maths, so sorry if these sounds simple. If I have a 3D geometry of a pipe which has its...

Jul1612 08:26 AM
athuss

3 
1,351 
reading that the commutator of rotations on two orthogonal axes is i * the rotation matrix for the third axis
but...

Jul1512 01:57 PM
BWV

2 
1,010 
Hello everybody, i am new to this forum, i am not a physist not a mathematician, just an architect and i have a...

Jul1512 12:06 PM
micromass

32 
9,969 
I'm trying to give an answer to the following problem, I hope someone could come in help! Consider a smooth...

Jul1512 09:00 AM
finsly

4 
1,082 
Hi all,
I'm currently writing an iPhone application where I'm taking the following ellipse which I created in Adobe...

Jul1512 03:10 AM
MaTHFRo

6 
1,548 
Hi everyone,
What is a covariant derivative? I have looked online but the explanations are not clear.
I just...

Jul1412 11:00 AM
quasar987

4 
1,675 
I've been scratching my head over this one. I'm trying to find a system of equations to solve for points R and S. The...

Jul1312 08:52 AM
chiro

3 
1,372 
So as I have read in Schutzs book on GR, and I'm finding his section on tensors and one forms very confusing.
...

Jul1112 09:47 PM
lavinia

15 
1,952 
I'm trying to work out the mathematics of this for a school project.
Say you have 4 beacons arranged in a square (I...

Jul1112 07:25 PM
chiro

4 
2,383 
This might be more of an algorithm question than a math question: how do I go about distributing n points as evenly...

Jul1112 09:18 AM
phyzguy

4 
1,389 
What mathematics are necessary for understanding and using minimal surfaces particularly in quantum field theory? As...

Jul1012 04:27 PM
JPBenowitz

5 
1,098 
I can't seem to find on the web a site that gives the Z cohomology of the infinite dimensional Grassmann manifold of...

Jul912 06:22 AM
lavinia

4 
1,303 
On a bipartite graph a game of cat vs mouse can be played, with say both the cat and mouse starting on a "red" vertex....

Jul812 10:35 PM
KOSS

2 
1,401 
I am reading Munkres book on Topology, Part II  Algegraic Topology Chapter 9 on the Fundamental Group.
On page...

Jul812 05:04 AM
lavinia

1 
928 
Hi all!
It's already a couple of days that I'm trying to solve this problem. I've been given the following Kahler...

Jul812 04:37 AM
L0r3n20

3 
1,106 
On page 333 in Section 52: The Fundamental Group (Topology by Munkres) Munkres writes: (see attachement giving Munkres...

Jul712 09:06 AM
lavinia

3 
1,205 
This thread asks for help calculating the Z2 cohomology ring of the Klein bottle using intersections.
This is what...

Jul712 08:07 AM
lavinia

3 
1,737 
Can someone explain to me in detail, why the ratio of the circumference of a circle to its diameter is not equal to pi...

Jul512 05:46 PM
Allojubrious

11 
1,733 
I'm not sure if this is the right section, but what the hell.
I've been looking to buy a bluray of fractal zooms,...

Jul512 02:55 PM
Doofy

0 
753 
There is a part in the proof of sard's theorem where we restrict our discussion to a point x such that Df(x)=0, and...

Jul512 02:53 PM
Tinyboss

1 
975 
I am reading Thurston's book on the Geometry and Topology of 3manifolds, and he describes the metric in the Poincare...

Jul512 02:25 PM
L0r3n20

4 
1,541 
Hello,
In R^3, the surface of the parallelogram determined by two vectors u and v is given by the norm of the cross...

Jul412 02:24 PM
coquelicot

26 
1,936 
Hi!
Does anyone know which is exactly the map of groups (2,3,∞) → (2,3,n) (from modular group to triangle group) as...

Jul412 07:25 AM
mery2

0 
693 
Hello,
I want to ask for a verification of something I did. Lets say I want to compute the mth cohomology group of...

Jul312 08:35 PM
lavinia

3 
1,595 
I think this a map of the Klein fourgroup geometry. Comments?...

Jul312 07:36 PM
micromass

57 
9,178 
Dear all,
I have a problem that I need to solve. (I have made posts previously about this as well). Quite simply...

Jul212 11:28 PM
chiro

1 
1,362 
consider we have n dimensional manifold,N
at point p we can define a vector
this vector is independent of our...

Jul112 06:07 PM
HallsofIvy

1 
599 
{(a_i)_j} is the dual basis to the basis {(e_i)_j}
I want to show that
((a_i)_1) \wedge (a_i)_2 \wedge.... \wedge...

Jun2812 03:16 PM
brydustin

1 
810 
Desargues' theorem:
Two triangles are in perspective axially if and only if they are in perspective centrally.
I...

Jun2612 05:10 PM
Ironben

0 
807 
Hi, I hope this is not too ignorant, but my Algebraic Topology is rusty:
Is there such a thing as DeRham...

Jun2612 07:30 AM
lavinia

10 
2,954 
Hi all!
I have some problems understanding the geometrical construction of Klein's quartic.
Starting from the...

Jun2512 04:12 PM
AntiCrackpot

1 
1,172 
Hi!
I'm trying to understand a proof for the fact that the isometry group of a symmetric space is a Lie group. The...

Jun2512 02:51 PM
Sajet

0 
730 
Hello,
I'm trying to define an axis as a set of 3 unit vectorsu, v, and w. at a given point P
Suppose we are...

Jun2512 09:16 AM
meldraft

3 
1,549 
Consider the following:
On a circle of radius 1, two points are marked: P1 and P2.
Two lines are drawn from the...

Jun2412 07:27 PM
Tinyboss

1 
913 
hi friends !! i have a little problem :
Let M and N be two varieties, such that N is a menu hermitian metric h. Let...

Jun2412 03:48 PM
math6

0 
809 