
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 
138,158 
Please post any and all homework or other textbookstyle problems in one of the Homework & Coursework Questions...

Feb2313 09:24 AM
micromass

1 
30,032 
Hello, I'm studying for a test and this is a question on a practice test...
cos(x)+y^2+(2yx1)y'=0
I can't...

Jul1512 12:54 PM
JJacquelin

3 
965 
Function is
(x  2xy + e^y) dx + (y  x^2 + xe^y) dy = 0
Okay so it is the standard convenient exact equation...

Jul1412 07:05 PM
NanoPassion

4 
1,173 
Hi,
Part of my research, I nondimensionalized an ODE to eventually arrive at this form:
sin(τλ) =...

Jul1712 01:06 PM
fnsaceleanu

7 
4,984 
anyone have any ideas on a technique to tackle this PDE:
u_{tt} = u_{xx} + u_{xxxx}
its like a 4th order wave...

Jul1612 12:04 PM
JJacquelin

1 
834 
Hello!
I have some examples of nonhomogeneous ODEs to be solved by the undetermined coefficients method. Two from...

Jul512 12:32 AM
haruspex

3 
1,628 
What is the use of Laplace transforms in differential equations? I mean, why are they used?
And can you please...

Jul2012 02:57 PM
Jonnyb302

11 
3,451 
I have previously taken PDE's and ODE's. I understand obtaining the equation y''+lambda*y=0 (lambda then giving the...

Jul1412 04:51 PM
ericm1234

12 
1,544 
Hi! A nice method for solving differential equations that occur in physics utilize greens functions as well as the...

Jul1112 04:12 PM
center o bass

2 
1,246 
L2] = ?

Jul2012 03:04 AM
maistral

26 
3,015 
I was given the solution to this problem:
y'=y^2+2y1, plot phase line, solve it, in terms of y(0)=y0, what happens...

Jul1412 04:53 PM
ericm1234

5 
818 
I have a question about calculus of variations that is driving me absolutely nuts right now:
I have followed the...

Jul1512 10:28 AM
Marioeden

1 
1,004 
The problem:
Appreciate help on the following
Hot water flows in an insulated copper pipe L long starting at...

Jul1312 07:25 PM
Mute

10 
1,573 
I've been searching online for the past week but can't seem to find what im looking for.
I need the analytic...

Jul312 12:50 PM
Mute

3 
1,028 
Can anybody tell the converted form of the Rodriguez formula from the nth derivative to a well defined power of a...

Jul312 02:46 PM
Blogical

0 
833 
Hello,
I'm having hard times with the following simple linear ODE coming from a control problem:
$$u(t)' \leq...

Jul512 03:36 AM
haruspex

3 
920 
I want to know the temperature profile of phase transition layer in the interstellar medium.
For stationary solution,...

Jul512 05:36 AM
omyojj

2 
903 
Hi all! I'm stuck with a system of PDE. I'm not sure I want to write it here in full, so l'll write just one of them....

Jul812 02:08 AM
L0r3n20

4 
1,019 
This is an extract from my third year notes on 'Computational Physics':
The Euler method is inaccurate because it...

Jul612 05:59 AM
Filip Larsen

1 
936 
Hello again.
First off, I wasn't sure how to say this in the title but I'm not taking the inverse Laplace...

Jul1012 12:51 AM
JJacquelin

3 
1,527 
Many texts in deriving the fundamental solution of the Laplace equation in three dimensions start by noting that the...

Jul912 08:28 PM
HallsofIvy

7 
1,840 
hi every body, im doing an analysis of a paper about a tool used in oil well drilling, they use 3D navier stoke...

Jul912 08:59 AM
iloc86

4 
923 
Hi,
I have an equation of the form;
\frac{d}{dt}(W) = \omega \left(x \frac{\partial}{\partial y}  y...

Jul912 04:53 AM
climbon

0 
611 
I have an autonomous system of two ODEs, i.e.,
dx/dt = f(x,y)
dy/dt = g(x,y)
I plotted the phase portrait in...

Jul1312 03:27 PM
ramparts

0 
684 
Ok, I know how to separate variables in solving an ODE. I am unable to understand a solution I have for a problem...

Jul1312 06:29 PM
ericm1234

2 
1,060 
Hi
Does anyone know what calculations should be used to minimize an energy functional (level set and active contour...

Jul1012 07:42 AM
pepe34

0 
618 
hi all,
I've been trying to work this problem out,
\frac{dv}{dt}A(Bv)^{1.6}=G
A, B and G are constants
...

Jul1212 01:36 AM
JJacquelin

6 
1,223 
Hello all,
I am dealing with a rather complicated problem (as we all do), without much knowledge in differential...

Jul1812 01:22 AM
haruspex

4 
1,342 
I'm reading up on some methods to solve differential equations. My textbook states the following:
"y_{1} and y_{2}...

Jul1212 10:54 AM
Somenath

1 
1,889 
Hi!This is a quite sophisticated problem, but it’s interesting and challenging!
Consider the following case: Let’s...

Jul1312 03:52 PM
marqushogas

2 
773 
Solve:
Δu=1, u(1, theta)=sin(theta). 0<r<1, pie<theta<pie, u finite at r=0
What I've done: u=u1+u2. Δu2=0,...

Jul1612 08:47 PM
Marioeden

11 
1,268 
xy''+y'=x
y(1)=0, y(0) bounded (so the natural log, 1/x etc. terms drop out)
homogeneous, cauchy euler: y=a+bx...

Jul1512 10:04 PM
ericm1234

11 
1,705 
Can anyone help me on this equation. I want to find a solution for dr/dt. a, b and c are constants.

Jul1512 11:13 AM
Nilupa

5 
1,327 
I am trying to solve four coupled equations. Three of them are first order differential equations and the fourth is a...

Jul1912 06:25 PM
tau1777

0 
605 
I am not too familiar with differential equations but am familiar with basic calculus, I came across this equation...

Jul1912 06:27 PM
haruspex

5 
1,305 
I thought of a method to solving poisons equation the other day, tell me if this is right.
we have,...

Jul2012 01:31 AM
haruspex

1 
887 
To my knowledge I assume:
Newton's second law of motion :
F = ma = mx''
Hooke's Law
F = ks where s is the...

Jul2012 04:02 PM
jlawson

3 
1,381 
i need the derivation of orthogonal properties of associated laguerre polynomial (with intermediate steps). someone...

Jul2212 06:11 AM
Marioeden

1 
1,133 
Working on recurance realtion.
Get to (sum(n=2))n*(N1)*a(n)*X^(n2)+(sum(n=0))a(n)*x^(n)
Try several things but not...

Jul2112 10:57 AM
Marioeden

1 
943 
Not even sure where to start on this one???
Is this a series solution problem?

Jul2112 10:42 AM
Marioeden

5 
927 
Hi
I am reading about the Langevin stochastic differential equation
\frac{d}{dt}p = \alpha p + f(t)
where p...

Jul2112 05:03 PM
Niles

4 
1,043 