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

Feb2313 09:24 AM
micromass

1 
43,869 
for cos y the critical points are n*pi  0.5*pi
for cos 2x, the critical points should be n/2 * pi  0.25*pi ...

Feb213 06:07 PM
pwsnafu

2 
475 
hi guys i'm stuck on this, i keep thinking i have the right answeres but i can't get them.
the function is f(x):...

Mar1305 03:59 PM
cronxeh

6 
1,065 
I was given f(x,y,z) = x4 + y4 + z4  x2  y2  z2.
I found that (or least I think it's these) x = 0 & \pm1/\sqrt{2},...

Oct909 09:43 PM
squenshl

2 
725 
Are inflection points critical points?
and what about at the value that f(x) undefined? Is that critical point too?

Nov412 03:25 PM
Bipolarity

2 
587 
Hi, Everyone:
I am having trouble figuring out what the critical points would be for any such map
f:R^n...

Oct210 05:42 AM
Petr Mugver

3 
922 
I have been studying the 'resummation' methods for divergent series..however i have some questions of critcs.
...

May2607 04:18 AM
tpm

0 
1,196 
Hi,
This is my first post. Sorry for the mistakes it certainly contains.
I have two questions. First, is there a...

Apr2611 02:12 AM
dextercioby

1 
756 
AX(BXC) = B(A(dot)C)  C(A(dot)B)
For the left hand side I got
(AyBxCyAyByCx+AzBxCzAzBzCx)x(hat) +...

Jan1205 07:35 PM
Dr Transport

6 
3,237 
Hey,
I have a problem that can be written in the following form:
u=v x w
where u, v, w are 3by1 vectors and x...

Apr3011 06:39 AM
azizz

2 
963 
I just saw an instructor of EEE (YouTube) talk about Cross Product. He gave an example of when cross products are...

Jul2809 06:41 PM
Phrak

16 
1,206 
Hi all,
Just having some trouble understanding a certain example of cross product. It's actually for physics, but...

Nov1811 03:40 PM
mathman

5 
1,248 
Hi.
I have an integral of a cross product:
\int a\times b(t)dt
a does not depend on t. How can I move it...

Oct1611 01:29 PM
timewalker

10 
14,921 
Hi everyone,
What does \int \vec{f} × \vec{dl} mean? does it mean "The Line Integral of Vector Function on a...

Feb1114 07:23 AM
Simon Bridge

7 
579 
Hello guys, this must be a very trivial question, but I just don't see it.
Ihave a "vectorized quaternion"...

Jul809 01:57 PM
nburo

2 
3,649 
Hi, I've been trying to derive the electromagnetic stress tensor on my own, and I've run into a bit of a problem. I...

Dec2910 11:21 AM
EricTheWizard

2 
4,009 
Is there any neat way/rule to write:
\vec B \times (\vec \nabla \times \vec A)
?
I've tried it myself and found...

Mar105 06:53 PM
dextercioby

3 
12,117 
The cross product between two vectors \vec{A}x\vec{B} and \vec{C} is given by the following equation:...

Mar712 08:09 AM
Mathoholic!

2 
2,081 
I have a question. Lets say you have three distinct, non zero vectors that lie in the same plane. Can I verify the...

Mar813 01:39 PM
timthereaper

4 
810 
"The area of a parallelogram spanned by two vectors, v1 and v2, is v1 X v2."
Would someone help me understand...

Apr2205 02:51 AM
mkkrnfoo85

2 
1,056 
If the area enclosed by an ellipse 4x^2+y^2=1 and its cross section is perpendicular to the xaxis then its volume is?...

Jan2604 06:31 PM
Nachtwolf

4 
1,894 
How do you find ∫ cscx dx?

Nov1603 12:37 AM
reinhard_t

13 
6,937 
The volume of a sphere with radius r is
v = \frac{4}{3}\pi r ^{3}
It makes sense that its derivative with...

Jul2313 05:57 PM
lurflurf

4 
724 
The question im looking at states:
Prove that the elliptical function x^2 + 3y^2=b is orthogonal to the cubic...

Nov307 06:33 AM
HallsofIvy

1 
1,912 
Hi
The curve C has equation y = f(x) and the point P(3,5) lies on C
Given that
f'(x) = 3x²  8x + 6
The...

Jan308 03:29 PM
HallsofIvy

3 
1,456 
on a ti83 calculator, how do you put in cubic roots?

Sep2403 01:36 PM
StephenPrivitera

2 
2,622 
So this is not an homework question, and I have solved the integral...
Just it took alot of time and was very...

Jul811 09:08 AM
andylu224

3 
1,020 
It's clear that f(x)=e^x has no solution for f(x)\le0. So can there be imaginary solutions for values not in the range...

Oct2707 05:14 AM
CompuChip

9 
2,966 
The integral I am seeking to evaluate is
int_{\inf}^{+\inf) exp(w/2) exp( i w ) dw
a definite integral which...

Dec2810 10:25 AM
lamarche

8 
2,333 
These identities might be considered as true:
\begin{array}{rcl}
1  1 + 1  1 + \cdots & = & \frac{1}{2} \\
...

Jun210 01:00 PM
g_edgar

20 
2,299 
i am having trouble with understanding the physical significance of these two operators.

Aug1607 05:49 AM
dx+dy

6 
2,558 
I noted that if f : C \to C is holomorphic in a subset D \in C, then \nabla \by \hat{f} = 0, \nabla \dot \hat{f} = 0....

Aug1111 01:45 PM
Termotanque

0 
1,023 
Hello people!
I've been working on this problem, but I can't find how differentials of V on the left side of the...

Apr1004 12:33 PM
matt grime

1 
1,701 
Regarding the equation for curl:
Nable E literally means the sum of the differences of certain rates of change with...

Jun1709 05:22 PM
rockyshephear

0 
1,368 
Can anyone show me how you get the curl in polar or spherical coordinates starting from the definitions in cartesian...

Apr2211 06:08 PM
Amok

8 
5,366 
I have a number of books which give a vector identity equation for the curl of a cross product thus:
\nabla \times...

Feb2711 07:33 PM
lurflurf

3 
5,908 
Okey Dokey, so I'm bored and decided to play around with some math. I've got a problem that I can't figure out now; I...

Mar1107 07:10 AM
HallsofIvy

2 
1,700 
trying to remember rules for curl test applicability.
is it just simple closed curve?
is F=ysin(x)i+cos(x)j...

Dec610 09:54 AM
HallsofIvy

3 
1,437 
Can someone give me analogies for each of these? I know the standard ones so try to be creative. I just received an A...

Dec2208 09:55 PM
daytripper

17 
3,255 
Have a parametric surface of revolution formed by the hyperbolic spiral equation. The 2d equation is y=1/x. The...

May711 08:05 PM
trustthrust

0 
1,205 
A quick question. In stewart, the curvature is defined as:
\kappa = \abs(\frac{dT}{ds})
and it says that:
...

Jul2805 04:51 PM
Crosson

26 
2,960 