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

Feb2313 09:25 AM
micromass

1 
31,115 
I'm having a little trouble seeing something Harris says in his intro book on alg. geom. Say X is contained in P^n....

Dec1912 02:19 PM
hlfmanhoffdor

2 
979 
According to this book I'm reading, if you cut out a closed disc in the projective plane, then the complement of the...

Dec1812 02:19 PM
Monobrow

5 
2,762 
I have got next interesting geometry example :)
I have got regular hexagon ABCDEF, when S (mark for area in...

Dec1812 12:32 AM
EebamXela

1 
809 
Hey guys, I need to fill up a box with uniformly distributed set of nonoverlapping spheres. This is quite easy to do...

Dec1712 03:30 PM
0xDEADBEEF

1 
956 
Hi,
I have a problem understanding something
This is a snapshot of a book I am reading
...

Dec1512 07:01 PM
Lajka

2 
848 
Hi
consider the following problem:
The plane is ruled by the lines y=n for integer n's.To this plane we drop a cross...

Dec1512 12:14 PM
hedipaldi

1 
844 
Note: this is not a H.W. problem. I'm just curious about it.
Imagine you are a flatlander living on a spherical...

Dec1412 10:16 PM
Storm Butler

8 
1,165 
Good morning,
I'm trying to compute the arclength (geodesic distance) between two ndimensional points over a...

Dec1412 11:11 AM
HallsofIvy

10 
1,789 
Hello,
I'm trying to compute the intersection point between a ndimensional vector and a nsphere.
Do you know how...

Dec1412 08:50 AM
7toni7

3 
1,002 
How do you calculate an object in 4 dimensions? Like the 4 dimensional cube. I understand that a point is the begining...

Dec1412 08:50 AM
meldraft

2 
1,020 
Hello, apologies in advance if my questions seem rather ignorant. I'm trying my best (and struggling) to understand...

Dec1312 04:19 PM
STENDEC

2 
1,532 
Hello,
it is true that linear transformations have constant Jacobian determinant.
Is the converse true? That is,...

Dec1212 08:59 PM
mathwonk

5 
1,388 
I have noticed that many theorems in classical geometry can be proven using vectors. Thus, I am naturally inclined to...

Dec1212 08:51 PM
mathwonk

7 
1,484 
Hey everyone!
I have the following question for you guys to settle an argument: If you were an inhabitant of...

Dec1212 07:49 PM
Spinnor

1 
1,054 
I want to find the equations for the circles (formed on the planes) when a sphere cuts the XY, YZ and XZ planes. What...

Dec1212 12:59 PM
sijad

4 
937 
Suppose you have two lines that intersect at the point O. Let's say the lines are OP and OQ. Could you construct a...

Dec1212 10:20 AM
Studiot

13 
2,285 
I'm trying to work out the following problem: Find the first two terms of the power series expansion for the volume...

Dec1012 08:19 AM
Vargo

3 
1,020 
My question relates to constructional geometry & matrices aren't to be involved in the solution because stated Math...

Dec912 01:45 PM
sorter

0 
1,350 
So in the process of giving us a crude definition of a trefoil knot, our professor talks a bit about a function on a...

Dec912 11:18 AM
lavinia

5 
1,219 
Hi everybody,
I hope that I chose the right Forum for my question. As the title might suggest, I am interested in...

Dec712 03:00 AM
timb00

3 
1,492 
Hi everyone,
I work as a mechanical engineer in Ws Atkins in the analysis and asessment of offshore structures. We...

Dec612 05:34 AM
Studiot

3 
987 
Hi
Can someone please explain to me how is the rotation for quaternions
pqp* = (p2  p2 )q + 2 (p.q)p + 2p(pXq)...

Dec512 11:10 AM
rsaad

0 
815 
Ok, so this relates to my homework, but I really can't find an answer anywhere, so this is more of a general question....

Dec412 10:00 PM
lavinia

3 
1,666 
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 
693 
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 
1,749 
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 
1,365 
Hi, Everyone:
A way of defining an orientation form when given a codimension1 ,
orientable nmanifold N...

Dec212 01:12 PM
quasar987

7 
1,766 
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 
1,658 
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 
1,024 
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 
902 
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 
1,083 
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 
1,077 
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 
1,016 
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 
1,239 
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 
1,624 
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 
1,093 
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 
910 
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 
2,219 
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 
1,013 
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 
1,067 