# Differential Equations

- An equation involving derivatives of a function or functions. Solving ODE and PDE
 Meta Thread / Thread Starter Last Post Replies Views Views: 123,612 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 95 136,688 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 29,605 Hello, I'm studying for a test and this is a question on a practice test... cos(x)+y^2+(2yx-1)y'=0 I can't... Jul15-12 12:54 PM JJacquelin 3 956 Function is (x - 2xy + e^y) dx + (y - x^2 + xe^y) dy = 0 Okay so it is the standard convenient exact equation... Jul14-12 07:05 PM Nano-Passion 4 1,159 Hi, Part of my research, I nondimensionalized an ODE to eventually arrive at this form: sin(τλ) =... Jul17-12 01:06 PM fnsaceleanu 7 4,881 anyone have any ideas on a technique to tackle this PDE: u_{tt} = u_{xx} + u_{xxxx} its like a 4th order wave... Jul16-12 12:04 PM JJacquelin 1 825 Hello! I have some examples of non-homogeneous ODEs to be solved by the undetermined coefficients method. Two from... Jul5-12 12:32 AM haruspex 3 1,603 What is the use of Laplace transforms in differential equations? I mean, why are they used? And can you please... Jul20-12 02:57 PM Jonnyb302 11 3,394 I have previously taken PDE's and ODE's. I understand obtaining the equation y''+lambda*y=0 (lambda then giving the... Jul14-12 04:51 PM ericm1234 12 1,522 Hi! A nice method for solving differential equations that occur in physics utilize greens functions as well as the... Jul11-12 04:12 PM center o bass 2 1,233 L2] = ? Jul20-12 03:04 AM maistral 26 2,987 I was given the solution to this problem: y'=-y^2+2y-1, plot phase line, solve it, in terms of y(0)=y0, what happens... Jul14-12 04:53 PM ericm1234 5 807 I have a question about calculus of variations that is driving me absolutely nuts right now: I have followed the... Jul15-12 10:28 AM Marioeden 1 995 The problem: Appreciate help on the following Hot water flows in an insulated copper pipe L long starting at... Jul13-12 07:25 PM Mute 10 1,562 I've been searching online for the past week but can't seem to find what im looking for. I need the analytic... Jul3-12 12:50 PM Mute 3 1,017 Can anybody tell the converted form of the Rodriguez formula from the nth derivative to a well defined power of a... Jul3-12 02:46 PM Blogical 0 819 Hello, I'm having hard times with the following simple linear ODE coming from a control problem: u(t)' \leq... Jul5-12 03:36 AM haruspex 3 909 I want to know the temperature profile of phase transition layer in the interstellar medium. For stationary solution,... Jul5-12 05:36 AM omyojj 2 890 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.... Jul8-12 02:08 AM L0r3n20 4 1,012 This is an extract from my third year notes on 'Computational Physics': The Euler method is inaccurate because it... Jul6-12 05:59 AM Filip Larsen 1 930 Hello again. First off, I wasn't sure how to say this in the title but I'm not taking the inverse Laplace... Jul10-12 12:51 AM JJacquelin 3 1,499 Many texts in deriving the fundamental solution of the Laplace equation in three dimensions start by noting that the... Jul9-12 08:28 PM HallsofIvy 7 1,800 hi every body, im doing an analysis of a paper about a tool used in oil well drilling, they use 3D navier stoke... Jul9-12 08:59 AM iloc86 4 912 Hi, I have an equation of the form; \frac{d}{dt}(W) = \omega \left(x \frac{\partial}{\partial y} - y... Jul9-12 04:53 AM climbon 0 605 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... Jul13-12 03:27 PM ramparts 0 678 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 1,043 Hi Does anyone know what calculations should be used to minimize an energy functional (level set and active contour... Jul10-12 07:42 AM pepe34 0 610 hi all, I've been trying to work this problem out, \frac{dv}{dt}-A(B-v)^{1.6}=G A, B and G are constants ... Jul12-12 01:36 AM JJacquelin 6 1,209 Hello all, I am dealing with a rather complicated problem (as we all do), without much knowledge in differential... Jul18-12 01:22 AM haruspex 4 1,323 I'm reading up on some methods to solve differential equations. My textbook states the following: "y_{1} and y_{2}... Jul12-12 10:54 AM Somenath 1 1,855 Hi!This is a quite sophisticated problem, but it’s interesting and challenging! Consider the following case: Let’s... Jul13-12 03:52 PM marqushogas 2 761 Solve: Δu=-1, u(1, theta)=sin(theta). 0