# Differential Equations

- An equation involving derivatives of a function or functions. Solving ODE and PDE
 Meta Thread / Thread Starter Last Post Replies Views Views: 5,739 Announcement: Follow us on social media and spread the word about PF! Jan16-12 Pinned: Intro. to Differential Equations ( 1 2 3 ... Last) My intent is to create a thread for people interested in Differential Equations. However, I will explicitly state that... Jul3-12 07:18 PM Luccas 95 139,030 Please post any and all homework or other textbook-style problems in one of the Homework & Coursework Questions... Feb23-13 09:24 AM micromass 1 30,398 Hi, could someone please link me to the relevant theorems etc (or explain personally) that answer the issue that... Apr4-11 07:15 PM Ben Niehoff 1 1,086 I'm a theoretical biologist in the process of developing a spatial model for animal movement. So far, I've arrived at... Apr24-11 03:40 AM JJacquelin 3 1,086 I'm trying to solve the heat conduction formula in 3 dimensions when there is constant generation from electrical... Feb1-13 01:03 PM pasmith 2 1,086 I've been trying (unsuccessfully!) to rearrange the following equation so that H is the subject: mgH = / 2 ... Mar24-10 10:24 PM hotvette 1 1,085 Ok, I know how to separate variables in solving an ODE. I am unable to understand a solution I have for a problem... Jul13-12 06:29 PM ericm1234 2 1,085 How can we say: f(x)=A'sin(kx)+B'cos(kx) or equivalently f(x)=Ae^{ikx}+Be^{-ikx}?? How are these two... Nov18-12 04:44 AM M. next 6 1,085 I would like to ask if anybody knows something about the methods of solving infinite linear autonomous systems of... Jul31-13 12:01 PM Mandelbroth 3 1,085 I'm having trouble understanding the concept of laplace transformations. my book states that it is comparing how... Apr26-05 09:04 PM Corneo 1 1,084 What method can I use to analytically solve the following 2nd order PDE? u=u(x,t) ∂u/∂t - a*x*∂u/∂x-D*∂^{2}u/∂t^{2}... Oct30-11 03:05 AM pangyatou 1 1,084 Hello I have no experience in solving such equations, the equation in question is \frac{dv}{dt}=-\alpha v +... Oct30-11 11:30 AM johnt447 0 1,084 is this the wriye formula of cofficient of friction 22/7 x D x n/12 May16-09 06:40 AM HallsofIvy 2 1,083 Hi Everyone, Apologies if this is posted in the wrong place. I am trying to produce numerical solutions for the... Jan25-11 10:37 AM rs12345 0 1,083 Hello Don't think this is homework, because I just want to know whether or not it has a solution (x^2 + x + 1)y''... Apr25-11 04:28 AM JJacquelin 5 1,083 Hi, I want to solve the following wave equation: u_{tt} - c^2 u_{xx} = f(x,t)u What is the best way to do it?... May28-11 11:00 AM Tohiko 2 1,083 Hi all, Suppose the solution of a pde exists and is unique, what can be said about the smoothness thereof? In... Nov30-09 05:54 PM Hootenanny 1 1,082 so im working on a problem and i have a question about the step function. lets say that a decaying force is f(t). with... Nov22-11 12:49 AM I like Serena 1 1,081 I don't understand what my professor told me. He said that if a fourieer series of a function f is not continuous then... Dec8-09 11:13 PM LCKurtz 4 1,079 I'm trying to solve this equation: Ux + Uy + U = e^-(x+y) with the initial condition that U(x,0)=0 I played... Apr12-10 08:09 PM gato_ 2 1,079 Hi everyone, Im looking for an autonomous first order ode that has the following properties. For dependent... Jan25-13 12:38 AM JJacquelin 7 1,079 Explain differential equation of order 3? With example? Nov26-08 05:02 AM HallsofIvy 1 1,078 Hey guys, I have a pretty simple question but I can't seem to find the answer anywhere. is y''+xy'-5=(x^2)(e^y)... Jan22-10 09:07 AM matematikawan 2 1,078 Hello everyone, I am solving an eigenvalue problem. Right now, I would like to know; How to determine the... May23-11 06:05 PM Urkel 0 1,078 Hi everyone, I have an equation that contains the derivative of the Bessel Function of the first kind. I need to... Nov19-12 07:26 AM KyleS4562 2 1,078 Is this problem possible? Solve the initial value problem x''(t) + 6x'(t) + 9x(t) = f(t); x(0) = N, x'(0) = M ... May18-11 04:35 AM JJacquelin 1 1,077 Hello, What does laplace transformation exactly 'do'? If I have PDE of second order and use LT on it, what do i... Dec4-11 05:02 PM hunt_mat 1 1,077 I am solving a problem involving Lagrange Multipliers and calculus of variations and have the equation: f_{x} -... Feb1-12 04:45 PM shank8 0 1,077 Hello guys, Which method can we use to solve the differential equation below? dy/dx= 1/(xy+x^2y^3) It doesn't... Apr7-05 09:07 PM Lyuokdea 5 1,076 can any one know how to derive the Lax pair for the cubic nonlinear schrodinger equation? currently I am interested... Mar16-11 07:23 AM saravanan13 0 1,076 Having a bit of trouble with this equation, I need to find V explicitly and this would obviously be done by... Apr28-12 08:40 AM JJacquelin 5 1,076 Hello, I am looking to apply to heat equation to a cylindrical rod and solving with explicit finite difference scheme.... Apr30-13 03:48 PM bigfooted 4 1,076 Hello everyone, I have the following differential equation : \dot{\theta}(t) = \omega(t) -... Aug20-09 03:14 PM Feldoh 6 1,073 Hello there, I am solving numerically the ODE $$\dot{y} = min \, (y, A) + B\, sin(t)$$ , A,B being constant. ... Nov29-12 01:26 PM Mute 1 1,073 Just a question that came to my mind while studying differential equations. Of-course this is a silly one (I... Oct15-11 03:11 PM HallsofIvy 1 1,072 Hi friends, I have been trying to solve the ode of second degree below: d2y/dz2=(i/a*z+b)*y i is the complex... Oct18-11 06:43 PM bloodlines 4 1,072 Eq u'(x)+p(x)u=f(x) with initial condition u(0)=0 It's homogenous solution is u_h=Ce^{-\int^x_0 p(s)ds} Jan7-12 05:14 PM matematikuvol 3 1,072 Hello, In my Differential Equations class we are learning about modelling with first order differential equations.... Sep28-13 02:55 AM UltrafastPED 3 1,072 Hey guys, I'm sure i'm doing something really daft in not getting this to work, but... I want to use NDSolve to... Jul5-10 02:39 PM rabbahs 1 1,071 Hello all, During the course of a calculation I was doing for my research, I derived a delay integral equation of... Jul15-10 02:58 PM Mute 2 1,071 Hello guys, I am new here to the forum and I was wondering if you could help me with some trouble I am having with... Oct29-10 11:56 AM Funzies 2 1,071 Can anyone tell me if this ODE has an analytic solution? And if it does, how the heck might I go about it? ... Dec10-10 06:46 AM JJacquelin 4 1,071