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

Feb2313 09:24 AM
micromass

1 
30,172 
My intent is to create a thread for people interested in Differential Equations. However, I will explicitly state that...

Jul312 07:18 PM
Luccas

95 
138,495 
I have an electrostatics problem (shown here: http://www.physicsforums.com/showthread.php?t=654877) wich leads to the...

Jan913 06:18 AM
Madoro

8 
1,626 
I am curious what the nonlinear bernoulli equation is used to model. Is there a certain topic or context where it...

Jan813 06:32 PM
SteamKing

2 
1,042 
y*dy/dx= y*Q(x)+ R(x)
I couldn't solve this equation wtih maple. does someone have an idea?
Thank you.

Jan813 03:24 PM
hayalkar

2 
755 
Hi All,
I have a problem in understanding the concept of dirac delta function. Let say I have a function, q(r,z,t)...

Jan813 07:26 AM
HallsofIvy

5 
969 
Is there some book in which I can read how to calculate Lyapunov exponents for differential and difference equation...

Jan713 04:04 PM
LagrangeEuler

0 
808 
I've got all the matrices in statespace form, but how do I solve them? I tried integrating the equations one by one,...

Jan713 08:27 AM
meldraft

1 
1,774 
I'm just starting my DE class, although I've been familiar with separable DEs for a while. Although they're (so far)...

Jan613 05:41 PM
samwinnick

3 
983 
Given an open connected subset D of the (t,x) plane and a function f\in C(D,\mathbb{R}), we say \varphi\in...

Jan513 06:15 PM
jacksonjs20

0 
816 
I found this initial value problem and was supposed to comment on the accuracy of Runge Kutta method. Please enlighten...

Jan413 07:36 AM
joqhey

14 
3,280 
I'm having difficulties trying to establish the best approach to create a mathematical model of a process that has a...

Jan413 12:22 AM
haruspex

6 
1,486 
Okay, so this is the first time I'm encountering this theorem and I'm not very strong in calculus. But I tried to...

Jan313 12:07 PM
indianaronald

1 
924 
I'm having some difficulties figuring out how to linearize second order differential equations for a double pendulum....

Jan313 05:54 AM
HallsofIvy

2 
1,693 
Hello Everyone
I am looking at equations of colliding particles in a granular gas and wondering how to calculate...

Jan213 10:14 AM
GGBCN

3 
1,188 
I have the following equation
\frac{\partial}{\partial y}\left(y\frac{dm}{dx}+m\frac{dy}{dx}\right)\frac{dm}{dx}=0...

Jan113 05:18 PM
I like Serena

14 
1,473 
In Rayleigh's DE :
http://www.wolframalpha.com/input/?i=rayleigh+differential+equation
What does mu stand for?

Dec3012 08:28 AM
atrus_ovis

4 
1,463 
I try to show, that equation
\frac{y}{ x^{2}+y ^{2} } + \frac{x}{ x^{2}+y ^{2}}y'=0
is not exact in...

Dec3012 06:47 AM
lurflurf

5 
1,849 
Plese give me silminer simple example or anther example on this case or explein the steps

Dec2912 01:14 PM
hazzzon

3 
763 
I have the following equation
\frac{\partial}{\partial y}\left(m\frac{dy}{dx}\right)=0
where y is a function of...

Dec2812 07:22 PM
haruspex

2 
2,333 
Hi, I'm new to the forum and need some help regarding my calc class. Any help you could provide would be greatly...

Dec2812 06:45 AM
HallsofIvy

5 
4,695 
Could someone give me an applied math example of the uniqueness theorem in the physical sciences (physics, chemistry,...

Dec2812 06:40 AM
HallsofIvy

1 
764 
Hi,
I'd really appreciate any help on this as I've spent many many hours trying to get my head around it. I am...

Dec2712 09:02 PM
Chestermiller

14 
1,852 
For example, if y=x^2, then the derivative of y is 2x. We write the derivative as either f'(x)=2x or dy/dx=2x.
...

Dec2712 12:05 PM
HassanEE

5 
4,285 
Can someone give me a qualitative example of the uniqueness theorem of a first order linear differential equation? I...

Dec2512 07:20 AM
HallsofIvy

1 
1,194 
What is the solution of the follwoing differential equation
\frac{\partial^{2}y}{\partial...

Dec2212 02:01 PM
JulieK

2 
1,184 
What is the logic behind equating differential equations to zero? For example the equation
y''5y'+6y=0
Because it...

Dec2212 07:49 AM
HallsofIvy

2 
1,255 
Hi all, I have a recursion relation I am trying to solve:
{X_n} = \frac{1}{{1  {\alpha _0} \cdot {X_{n  1}}}} \to...

Dec2212 07:28 AM
bjnartowt

2 
876 
Why we always write equation in form
y''(x)+a(x)y'(x)+b(x)=f(x)
Why we never write:...

Dec2112 10:56 AM
HallsofIvy

4 
1,085 
Why sometimes we search solution of power series in the way:
y(x)=\sum^{\infty}_{n=0}a_nx^n
and sometimes...

Dec2112 03:11 AM
tinytim

3 
999 
This may be vague, so I apologize.
I am interested in applied mathematics, so my question is about the process a...

Dec2012 02:41 PM
bigfooted

1 
1,005 
Hello, i have a problem solving this ecuation
dy/dx=(2*x*y3*x^2*y^3)/(x^3+2*y*x^2)
im using mathematica and...

Dec1912 04:59 PM
mariano2

0 
901 
1. The problem statement, all variables and given/known data
General solution for eccentric spheres, smaller...

Dec1812 10:38 PM
gparker267

0 
1,040 
Hi all. I'm trying to solve this PDE but I really can't figure how. The equation is
f(x,y) + \partial_x f(x,y)  4...

Dec1812 05:35 PM
pasmith

1 
845 
The length of the side of the square is a. The boundary conditions are the following:
(1) the left edge is kept at...

Dec1812 07:14 AM
Chestermiller

13 
2,247 
Is there a way to "crudely" approximate PDEs with Fourier series?
By saying crudely, I meant this way:
Assuming...

Dec1712 08:01 PM
chiro

1 
854 
Question:
Show that the system
x'= xyx
y'= x+y y
has at least one periodic orbit.
I know that I need...

Dec1612 04:14 PM
pasmith

1 
1,021 
hello, everyone. Recently I confront with the integral differential equations(ide's) in my research. Anyone can help...

Dec1612 09:40 AM
Mute

3 
1,289 
Use the orthogonality relation of Bessel function to argue whether the following two integrals are zero or not:...

Dec1512 01:33 AM
samuelandjw

4 
1,836 
http://img22.imageshack.us/img22/9595/capturecv.png
This image is from Thomas's calculus, 10th edition, chapter 9...

Dec1312 07:47 PM
Chestermiller

4 
1,212 
I was busy doodling and basically ended up constructing this differential equation:
p'(t)=c(t)p(t)c(tT)p(tT)
...

Dec1212 12:32 PM
euroazn

3 
1,052 
Hello everybody!
While solving some physical problem I got stuck with some system of integral equations.
The...

Dec1212 09:30 AM
jannyhuggy

1 
909 