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

Feb2313 09:25 AM
micromass

1 
30,118 
Has anyone written on differential geometry for complex spaces where rather than z = x + iy we use z = r e^it (Polar...

Dec312 11:49 PM
thehangedman

0 
681 
Hi All, I'm not a math guy so I am coming to you for help.
I am trying to come up with an equation to graph any 180...

Dec312 12:06 PM
JimEd

8 
1,701 
Hello!
I have a problem. How can I convert a left part from picture which is in coordinate system
(r, s) to...

Dec312 05:30 AM
soks

4 
1,334 
Hi, Everyone:
A way of defining an orientation form when given a codimension1 ,
orientable nmanifold N...

Dec212 01:12 PM
quasar987

7 
1,719 
Hi, All:
I'm trying to show that the Mapping torus of a manifold X is a manifold, and I'm trying to see what...

Dec112 01:05 AM
WWGD

7 
1,611 
Hi,
I'm trying to understand the fiber bundle formulation of gauge theory at the moment, and I'm stuck on the...

Nov2912 09:07 PM
...?

2 
993 
Hello,
I would like to ask you some questions.
1) I've a closed curve (for example an ellipse, which may...

Nov2912 11:14 AM
SteamKing

3 
878 
I have a list of points on a 2D simple closed curve and I'd like to approximate that curve using a polynomial such...

Nov2812 03:10 PM
Integratethis

0 
1,051 
Hi I'm working on a project where I need to develop a flight path to cover a circular area. I was thinking of having...

Nov2812 01:29 PM
rhimmelblau

2 
1,050 
I been reading some material that lead me to understand that it takes an inner product of a dyad and a vector to...

Nov2712 11:45 PM
jedishrfu

1 
998 
I have a (3 x N) matrix of column rank 2. If each column is treated as a point in 3space, then connecting the points...

Nov2412 12:39 PM
weetabixharry

2 
1,218 
I'm trying to find a reasonably fast method for testing whether or not a point (x,y euclidean coordinate system) lies...

Nov2412 04:11 AM
Physt

3 
1,576 
If X is a left invariant vector field, then L_x \circ x_t = x_t \circ L_x , where xt is the flow of X and Lx is the...

Nov2212 05:46 PM
demonelite123

0 
1,062 
Hello! I came across the following formula for the change in the subtended angle (of a circle), when we move our...

Nov2212 09:17 AM
Kontilera

0 
893 
Hairy ball theorem  Wikipedia is not as good or as wellreferenced as I'd hoped, and it mainly discusses vector...

Nov2112 01:19 PM
mathwonk

8 
2,122 
Hi all,
does anyone know if there exists a result that proves/disproves the following?:
"If a halfspace \{x \in...

Nov2112 10:18 AM
hwangii

0 
994 
Hi,
I wish to study (nontrivial) algebraic functions which have varied cycles at a few places other than the...

Nov2112 09:17 AM
jackmell

1 
1,051 
Hi guys, I have a very general question but I would like opinions asap. I am doing a project on Hilbert...

Nov1812 07:07 PM
micromass

1 
1,119 
Hi, Again:
I'm trying to show that, given a 3manifold M, and a plane field ρ (i.e., a distribution on
TM) on M,...

Nov1712 06:47 AM
quasar987

11 
1,820 
Hi, All:
There is a standard method to construct a nowherezero form to show embedded
(in R^n ) manifolds are...

Nov1512 03:53 PM
lavinia

8 
1,274 
hello,
I'm trying to understand catmullclark A. but I'm having a hard time with this...

Nov1312 06:48 AM
kiyoshi7

0 
965 
I've been thinking of a solution, but can't find a one. You have a square of side length 1. You have to draw 2 circles...

Nov1212 05:40 PM
Studiot

2 
1,049 
Hello!
I am a bit confused about how I can use covector fields on a differentiable manifold.
John M. Lee writes...

Nov1212 10:10 AM
Vargo

6 
1,632 
Hello,
can anyone suggest a geometric interpretation of the metric tensor?
I am also interested to know how we could...

Nov1212 09:17 AM
lavinia

12 
2,235 
Suppose that points x and y are given in Euclidean space. Point x is displaced to point x1 by
x1=x+a(xy)
Given...

Nov1212 07:27 AM
tinytim

3 
1,040 
Hi, All:
I need some help with some "technology" on differential forms, please:
1)Im trying to understand...

Nov1212 07:26 AM
quasar987

1 
902 
Hello everyone,
I'm studying basic graph theory, and my instructor gives me these statements to translate into...

Nov1112 07:35 PM
Simon Bridge

1 
898 
Say I have a function F(x,y)=(f(x),g(y)), F:X×Y→X'×Y'. Is there a theorem that says if f:X→X' and g:Y→Y' are...

Nov912 04:15 PM
sammycaps

10 
1,543 
I am currently reading a paper discussing the convexity of the image of moment maps for loop groups. In particular, if...

Nov912 02:32 PM
Vargo

3 
1,089 
So I'm having a little trouble with the part of Van Kampen's theorem my professor presented to us. He called this the...

Nov912 08:36 AM
sammycaps

4 
1,284 
If the hyperbolic paraboloid z=(x/a)^2  (y/b)^2
is rotated by an angle of π/4 in the +z direction (according to...

Nov812 11:45 AM
BrainHurts

2 
1,205 
I know that physically, they describe relationships whereby, for instance a vector field, for each point in three...

Nov612 03:58 PM
djpailo

5 
1,821 
Does anyone have a good book or reference on computing riemannian connections. I'm looking at Do Carmo and can't find...

Nov612 03:49 PM
lavinia

2 
1,105 
Let S1*(S2*) be the polar cone of the set S1(S2) (http://en.wikipedia.org/wiki/Dual_cone_and_polar_cone).
How can I...

Nov412 06:14 PM
avilaca

5 
1,385 
Hello!
I seem to have a problem with spherical coordinates (they don't like me sadly) and I will try to explain it...

Nov312 10:00 PM
chiro

3 
1,871 
When given a cylinder with radius, height and thickness, how does one go about computing the amount of material used...

Oct3012 09:22 PM
Vargo

1 
839 
All,
I am trying to determine the length of line across 3 dimensions (XYZ). My X&Y are WGS 84 coordinates and my Z...

Oct3012 03:43 PM
entombedtrade

0 
851 
given a compact, orientable, ndim. Riemann manifold, what is a sufficient condition for globally vanishing curvature...

Oct3012 11:36 AM
lavinia

5 
1,316 
Suppose a set of k arbitrary points, x_i, 1<=i<=k, x_i from R^2 are selected from a line. How can it be shown that a...

Oct2912 11:34 AM
Vargo

6 
1,144 
Find the vertices of α(t) = 1  2 cos(t)
I know that to find the vertices we have to set the curvature equal to...

Oct2912 08:02 AM
lavinia

2 
1,005 