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 
121,257 
Please post any and all homework or other textbookstyle problems in one of the Homework & Coursework Questions...

Feb2313 09:24 AM
micromass

1 
25,855 
Hello
Did an exercise and a small simulation to expand f(x)=x, defined on 0<x<3 in a FourierBessel series using...

Dec110 09:02 AM
rezaborhani

12 
14,631 
Hello everybody,
could you please direct me how to solve this nonlinear differential equation analytically, so by...

Nov1110 10:38 PM
Dickfore

20 
3,650 
I have the following elliptic equation that I must solve:
a\frac{\partial^{2}\phi}{\partial...

Nov1110 03:54 PM
fzero

7 
1,067 
The initial mass of fish in a lake was 7 thousand pounds on January 1st, 2001. Since the time, there was a 4year...

Nov1210 06:44 AM
HallsofIvy

1 
1,190 
Hi everyone,
This is more of a numerical question but I felt this would be the most appropriate forum. I apologise...

Nov1110 04:02 AM
pamparana

0 
1,574 
Problem:
y'+2y=4(x+1)2 > y=5e2x+2x2+2x+1
1. What the Order of the ODE?
It's 1st order
2 How do you check...

Nov2310 09:27 AM
eskie

7 
2,334 
dx/dt= x+y
dy/dt= 2x
x(0)=0
y(0)=1
I'm not familiar how to solve a system like this. Somebody plz help?
...

Nov1210 11:09 PM
maverick280857

8 
2,248 
x' = y2x
y' = 2xy
Whenever you look for equilibrium points x'=0 and y'=0, y=2x for both cases. What is the...

Dec210 05:52 AM
epenguin

5 
2,297 
yIII+yIIyIy = 0
I used the characteristic equation and got:
r3+r2r = 0
r (r2+r1) = 0
Which means that...

Nov1210 06:29 AM
HallsofIvy

1 
13,356 
I am considering a second order ODE of the form y''(x) + f(x) y(x) = 0, with boundary conditions that y(x) = 0 at...

Nov1210 10:16 AM
mordechai9

0 
2,222 
Hello
I'm trying to solve the following DGL with an integrating factor:
x'=xg(y)
y'=yh(x)
which is...

Nov1310 10:44 AM
heinerL

1 
1,225 
Hi,
My differential equations professor wanted us to think about this problem:
How would you go about modeling...

Nov1610 09:01 AM
jambaugh

2 
2,257 
Hi there, I am a young mathematician and I have discovered that Dirichlet's boundary problem is ill posed... Anyone...

Nov1510 04:06 PM
arildno

1 
1,677 
Hello,
My course is a bit vague on this topic.
1 First of all it states: if the differential equation A(x)y''(x)...

Nov1810 08:03 AM
HallsofIvy

1 
2,030 
Hi,
Could someone please show me how to solve the following simple problem using the RungeKutta (RK4) integration...

Nov1810 08:54 AM
HallsofIvy

3 
1,920 
Hello,
Sfunction! in Simulink/Matlab
does anyone solve ODE in Sfunction! in Simulink C++ blocks instead of...

Nov1810 12:05 PM
mbolhi

0 
2,040 
The equation of motion of a rocket with mass depletion during ascent and subject to drag forces can be written as
...

Nov2210 01:57 PM
Rruffpaw

7 
2,654 
I have an ellipse of a rl circuit and a rc circuit but now i am confused on how to obtain the phase angle.
i know...

Nov2110 02:51 PM
noname1

0 
1,869 
y''+9y=sin(3t)
I need to solve the above using the method of undetermined coefficients.
I have already found the...

Nov2310 11:11 AM
phantomcow2

4 
2,549 
Hey everyone. I'm trying to refresh myself of solving linear ODEs. For simplicity's sake, I began by trying to solve...

Nov2310 02:24 AM
arenaninja

2 
1,230 
Find the Particular Solution. Show the steps of derivation, beginning w/ the general solution....

Nov2310 12:10 PM
Matthew Rodman

1 
1,004 
x^2 y'' + x y' + n^2 y = 0 \; Is Euler equation and solution is y=x^m
I understand the three cases with different...

Nov2410 09:30 AM
HallsofIvy

4 
1,505 
I can not how define way to solve these equation
x(lx)y''+4y'+2y=o
If any one can help

Nov2610 09:21 AM
HallsofIvy

4 
1,209 
Hello,
Thanks at first. If anyone can understand, then I would like to know how do I get to equation 4.15. Its a...

Nov2610 09:10 AM
hgfalling

3 
955 
Hey Guys.
Im trying to find an inverse laplace transform for fraction in the laplace domain but cant find it in any...

Nov2610 09:23 AM
HallsofIvy

2 
941 
I was asked to seek for a harmonic function u(x,y) in the 2dimention disk whoes boundry condition is...

Nov2610 03:26 AM
JJacquelin

1 
1,126 
This appears on the bottom of p.279 of this book.
The author begins with Green's second identity:
\int_V \alpha...

Nov2810 02:21 AM
kakarotyjn

6 
1,323 
why is a_{11} dy^2  2a_{12} dxdy + a_{22} dx^2 = 0 the characteristic equation of a_{11} \phi _x^2 + 2a_{12} \phi...

Nov2710 06:09 AM
kakarotyjn

0 
705 
Zero input means input equals zero
the input is to some differential equation D2x = Dx + x + Input
the input =...

Nov2810 03:27 AM
zhermes

3 
1,408 
Hey all!
I'm trying to use the RungeKutta method on this differential equation but I am getting nowhere and it's...

Nov3010 02:31 PM
EnumaElish

2 
1,691 
Suppose I wanted to know the surface integral of a recently whose points are (0,0,0),(0,0,2),(1,1,0),(1,1,2)
The...

Dec110 11:12 PM
LCKurtz

1 
932 
The problem:
You are given the problem of analyzing the dynamics of a line of cars moving on a onelane highway. One...

Dec110 05:13 AM
jackmell

1 
1,485 
For the pde below
$d^2G(x,y)/dxdy+(a(x,y)1)*dG(x,y)/dx*dG(x,y)/dy=0$
how do I show the existence of G(x,y) given...

Dec110 11:02 PM
toptrial

0 
874 
Hello,
Let us assume we have a differential equation
( \frac{d^2}{dx^2}+ \frac{2}{1+1/n}\Theta_n^{n1}  \nu^2...

Dec210 06:52 AM
omyojj

0 
984 
I want to preface this by saying that these questions are not to find an exact answer, just to build intuition. If you...

Dec410 09:53 AM
farleyknight

0 
1,784 
Alright, so I have a general question on finding the general solution of the eq:
...

Dec510 01:47 AM
JJacquelin

1 
1,608 
greetings
what does a integrating factor tells about a differential equation?
in order to find the solution for a...

Dec610 10:14 AM
HallsofIvy

1 
2,142 
http://en.wikipedia.org/wiki/Girsanov_theorem
Could anyone tell me what does the of t mean in the attached...

Dec610 06:12 PM
tennishaha

2 
1,510 
Hi I need to find the solution of
d^2y/dx^2 + 2x(dy/dx) = 0
I've solved it in Maple and get that
y=a*erf(x)+b...

Dec610 06:01 PM
Juggler123

2 
1,761 
Dear Physics Forums,
I have a reaction scheme with 4 states where A<>B, B<>C and B<>D:
C
/
A...

Dec710 12:35 PM
Coomb Raider

1 
570 