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

Feb2313 09:24 AM
micromass

1 
46,611 
hi there,
just new to this form

Nov1209 04:25 PM
mathman

4 
1,156 
Hi,
I need two simple proofs of complex inequalities.
1) 1z/z<2
2)1+z/z>1/2
Ik need them for a...

Nov1209 03:03 PM
Belgium 12

2 
737 
so I have a semi circle that goes from
\frac{5\pi}{4} to \frac{\pi}{4}
so the angle between the x axis the...

Nov1209 09:37 AM
LumenPlacidum

1 
1,858 
I need to find the vertical sections and level curves of the function z=max(x,y^2) associated with the constant...

Nov1209 08:55 AM
LumenPlacidum

1 
2,009 
Hello! I wanted to solve this integral but really didn't understand the method show in the book.
Can anyone help me...

Nov1109 03:37 PM
kranav

2 
902 
Let b be a real number. Correct me if I'm wrong, but it seems that:
(1) The interval (b,b) is empty, as are the...

Nov1109 03:30 PM
Hurkyl

1 
594 
What is the algebra required to rewrite the nth term of: (sum from n=0 to infinity) of (pi^n)/(3^n+1) in geometric...

Nov1109 03:16 PM
ollybabar

2 
2,107 
Hi all,
In proof of derivative of lnx,
\frac{d}{dx}(lnx)=\lim_{\Delta x\rightarrow 0}\frac{\ln(x+\Delta x)lnx...

Nov1109 01:01 PM
l'Hôpital

1 
2,957 
given the set of moments m_k
obtained from the known measure w(x) \int _{\infty}^{\infty}dx w(x) x^{k} = m_k ...

Nov1109 12:31 PM
zetafunction

0 
617 
Recently, I proved that Given f:A \rightarrow \mathbb R is uniformly continuous and (x_{n}) \subseteq A is a Cauchy...

Nov1009 04:45 PM
snipez90

3 
984 
define F(x)=x, then uF is the lebesgue stiljes measure
duF=dx
Let y=x^2
we all know that how to transform \int...

Nov1009 06:58 AM
emamm

4 
2,054 
The energy of a magnetic dipole in an external magnetic field is
U =  \mathbf{m} \cdot \mathbf{B}
Yet if I try to...

Nov909 04:16 PM
fantispug

8 
5,572 
I always have trouble sketching regions and solids.
For example, if one solid described by the inequialities (in...

Nov909 12:44 PM
LCKurtz

2 
1,726 
If two spheres of radius 1 intersect each other so the surface of each sphere passes through the other’s center how...

Nov909 11:44 AM
volleyball21

2 
1,286 
Hey:
How to get the green function for laplace equation with dirichlet on the boundary for a CUBE domain?
I've...

Nov909 10:48 AM
Kaiser.LIU

0 
3,064 
How would I calcluate a surface integral in dimensions greater than 3.
For example, from the definition of a...

Nov909 09:49 AM
Hurkyl

1 
806 
Hello,
The general solution of a differential equation for y'+P(x)y=G(x) is
y(x)=e^{\int P(x)dx}
for y'+xy=x...

Nov809 12:07 PM
coki2000

2 
2,832 
I'm trying to express the polar rose as an implicit function:
r(t)=sin t
x = sin t * cos t
y = sin^2 t
Since...

Nov809 06:44 AM
tinytim

10 
1,587 
Hello!
Can you tell me the sufficient condition for the existence of the vector potential?
Thank you very much!

Nov709 07:19 PM
ManuelF

4 
1,126 
As mentioned in the title~
Could anyone give me a hint or an idea ?
Thanks~

Nov709 10:17 AM
abcdefg10645

2 
3,103 
I'm not completely familiar with measures yet, but am trying to be. I'm trying to show a that a few sets in Rn have...

Nov709 09:36 AM
rochfor1

6 
3,701 
given a function f(x) with a truncated Taylor series
f(x)= a_{0}a_{1}x+ a_{2}x^{2}a_{3}x^{3 } ...
even in...

Nov709 05:48 AM
zetafunction

0 
1,853 
I'm trying to show that a function f(z) is analytic by showing f'(z) exists. But f(z) is defined in terms of a contour...

Nov609 07:18 AM
Phyisab****

2 
1,857 
Could someone explain this to me please where n=y/squareroot(4vt)
∂C/∂t=(dC/dn)(∂n/∂t)=(1/2)(n/t)(dC/dn)
When i...

Nov509 08:48 PM
juice34

2 
646 
My textbook notes that if:
\frac{x^{2}}{a^{2}}+ \frac{y^{2}}{b^{2}} + \frac{z^{2}}{c^{2}}=1
and a \neq b \neq c...

Nov509 07:55 PM
IniquiTrance

2 
736 
I honestly enjoyed using James Stewart (yes heathen) when I did calc I, II, III and now these forums are buzzing with...

Nov509 04:52 PM
heldervelez

5 
2,930 
I am trying to measure a concrete structure to compute the surface area.
I have included a sketch of the structure...

Nov509 12:21 PM
jonlorio

1 
1,367 
Hello 
I have a problem in general finding the region in which the Laurent series converges...
Could someone...

Nov509 03:49 AM
Butelle

4 
966 
the idea is , do orthogonal polynomials p_{n} (x) have always REAl zeros ?
for example n=2 there is a second...

Nov509 03:46 AM
HallsofIvy

5 
1,951 
Does anyone know how to solve for x in the following equation:
x + \sqrt{x} = 6
I don't know how to solve for x...

Nov509 03:43 AM
HallsofIvy

4 
804 
How do you explicitly solve for x in terms of y using this quadratic formula?
y = 2x2 + x
I need to solve for x...

Nov509 03:36 AM
HallsofIvy

2 
1,355 
would in = an infinite amount of real possibilites if n is complex. considering that 1+0i is still a complex number,...

Nov409 05:26 AM
slider142

4 
948 
I`ve encountered this limit in a book i`ve been reading.
\lim_{t_c \rightarrow 0} \frac{1}{t_c} \int_0^{\infty}...

Nov409 04:44 AM
muballitmitte

1 
1,154 
If you have dv/dt you say to yourself its the derivative of v with respect to t. But in an example of deriving the...

Nov409 04:01 AM
HallsofIvy

9 
1,089 
How to prove the following inequality: for complex z such that Re z < 0 :
\left e^z1\right < \left z\right ?

Nov409 02:14 AM
smyroosh

2 
934 
nm, made a logical error. back to the drawing board.

Nov309 10:53 PM
TaylorWatts

0 
684 
Hi:
____________________________________________________________________
Added Nov.3, 2009
(For anyone who can't...

Nov309 03:30 PM
JG89

1 
1,448 
So I'm supposed to do this but is it just me or is it too hard to do this analytically? (I put it into wolfram online...

Nov309 07:56 AM
Pere Callahan

1 
2,271 
Please help required with this integral:
(x/(xa))^0.5 where "a" is a start distance of 10^3 and the final distance...

Nov309 07:20 AM
Per Oni

3 
950 
Is it true that every open set contains a compact set?

Nov309 06:42 AM
g_edgar

3 
2,048 