# Differential Equations

- An equation involving derivatives of a function or functions. Solving ODE and PDE
 Meta Thread / Thread Starter Last Post Replies Views Views: 123,109 Announcement: Follow us on social media and spread the word about PF! Jan16-12 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 29,593 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 95 136,634 I want to be able to map the position of a planet given initial position, velocity, and acceleration. I know the... Y 08:21 AM Juan Carlos 2 1,824 Hi!, I'm working on a personal project: Solve the heat equation with the semi discretization method, using my own... Y 08:08 AM Juan Carlos 2 125 Hi all, first of all I apologise if my question is not supposed to be in this thread. I am a fledgling mathematician,... Y 02:46 AM csb 0 118 Hey there, I have modeled a propagating wave in a 1D dispersive media, in which square and cubic nonlinear terms... Y 01:14 AM Strum 2 1,732 How to understand Uniqueness and existence theorem for first order and second order ODE's intuitively? Jul28-14 02:51 PM homeomorphic 3 366 Hi. First off, sorry for the not so descriptive title. If one of you finds a better tilte I will edit it. We have... Jul28-14 03:27 AM Strum 1 609 Can anybody give me some links for plotting bifurcations online? Jul27-14 08:15 AM ion santra 0 256 Hello Everyone. I have a question. Suppose I have a differential equation for which I want to find the values at... Jul26-14 12:39 AM crossfire234 1 672 I'm currently reading Tolstov's "Fourier Series" and in page 58 he talks about a criterion for the convergence of a... Jul25-14 02:49 PM jbunniii 2 525 When deriving the Runge-Kutta Method to solve y'=f(x) we need to use Taylor expansion. Hence we need to differentiate... Jul23-14 01:30 AM matematikawan 4 767 My textbook says that: "A differential equation contains both the function and the derivative of the function" ... Jul22-14 04:31 PM johann1301 3 605 I want to show, in a talk, how to build the Predator-Prey (Lotka Volterra) model. It starts off with the "Population... Jul22-14 07:09 AM dkotschessaa 2 586 Suppose we have some partial differential equation for a scalar ##f## $$Df = \rho$$ taking values in... Jul21-14 11:27 AM center o bass 0 479 According to the confluent hypergeometric equation \frac{d^2}{d x^2} y + \left(c - x \right) \frac{d}{d x} y - a y =... Jul20-14 03:44 PM Domdamo 3 1,847 For the following problem \frac{dw}{d\theta}=\theta w^{2}sin(\theta^{2}), w(0)=1 I am not able to obtain the... Jul20-14 04:15 AM verty 3 1,049 Hi, I'm trying to find the first integral of motion for this set of PDE. I'm not really that familiar with this... Jul17-14 11:44 AM Alicelewis11 2 3,114 Hi - wondering if you can help me find a solution of: \nabla^{2}u-\frac{u}{\lambda^{2}}=a\delta(r) for spherical... Jul17-14 09:17 AM jasonRF 3 2,285 Consider the following linear functional operator: $$Q_w = \lim_{h\rightarrow w} \lbrace \frac{f(x + h) - f(x)}{h}... Jul16-14 06:17 PM da_nang 1 1,274 Does anyone know how to prove this identity? I don't quote understand why the associated Legendre function is allowed... Jul16-14 05:19 PM HasuChObe 2 1,106 Hi, I am having a problem implementing 4th Order Runge Kutta (RK4) to solve a non linear ODE. dy/dt = B(t) -... Jul16-14 03:04 PM AlephZero 2 1,151 I'm doing a practice problem I found online, and I get a solution, but I think it should have a sine term in it. I... Jul14-14 06:21 AM pasmith 1 1,502 As it can be read here, http://en.wikipedia.org/wiki/Laplace_transform#Relation_to_power_series the Laplace transform... Jul12-14 08:23 AM HallsofIvy 2 1,420 For a regular LR circuit (L and R in series) and with a AC voltage: http://i.imgur.com/R8yRjNY.jpg I tried to... Jul11-14 05:18 AM Waxterzz 2 1,716 Hi, Are there any numerical techniques I can use to solve differential equations with periodic boundary conditions? I... Jul10-14 04:44 PM SarthakC 8 1,848 Is it possible to solve a differential equation of the following form?$$\partial_x^2y + \delta(x) \partial_x y +... Jul9-14 09:26 AM the_wolfman 1 1,728 This is about attempting to solve ##\left( y'\right)^2 = y^2 - 1 ##. \int\frac{dy}{\sqrt{y^2 -1}} = \pm \int dx ... Jul9-14 05:47 AM pasmith 2 1,317 f(z) = sq. rt of z-1 / z+1 --- both numerator and denominator are inside the radical. I can write it as (z-1)^1/2... Jul7-14 07:33 PM HallsofIvy 2 1,728 Hello, everybody. I'm trying to replicate plots from Yang et al. 2002. Spatial resonances and superposition... Jul5-14 10:47 AM jssdenton72 2 2,512 Is it possible to convert a general linear second order boundary value ode y'' + P(x)y' + Q(x)y = g(x), y(a) = y_a,... Jul5-14 03:12 AM bigfooted 1 1,809 I am setting up a numerical simulation from a 2D discretization of the heat equation in cylindrical coordinates. my... Jul4-14 12:55 PM geetar_king 2 2,254 If I have a function "F" in a two-dimensional space F(x,t) and its analog F' in another co-ordinate system F'(x',t')... Jun30-14 03:23 PM MathematicalPhysicist 1 1,999 Hi, I desperately need help to solve the following differential equation for buckling of a beam with a uniform... Jun30-14 06:51 AM AlephZero 20 5,748 Are these statements correct, if not could you give me an example 1. If solution of IVP is non-unique then there... Jun27-14 02:58 AM kochibacha 1 1,793 Hi, all. I'll be brief. Can Airy functions be considered orthogonal over some interval? If so, what is their... Jun26-14 10:49 PM skujesco2014 2 1,906 Hello! This is my first post to this excellent forum! I would like some help with this exercise: u_{xx} (x,y) +... Jun25-14 09:10 AM UltrafastPED 1 1,823 The Schrodinger equation is of the form \frac{d^2 \psi}{dx^2}+ \psi=0. In a lecture, the lecturer said that if we... Jun25-14 12:10 AM Shyan 4 2,237 Hİ. How can we sure that the initial conditions , say, for a second-order linear equation must be unique which is also... Jun24-14 12:09 PM mech-eng 2 1,811 Hi there! I have the following property: If x(t) is a solution of \left\{ \begin{array}{l} \dot{x} = f(x) \\... Jun23-14 06:38 PM brunob 2 1,806 Hi, all. While solving a second order linear differential equation why do we have to use linear independent but two... Jun23-14 06:50 AM SteamKing 6 1,960 Hello, I am searching for the Laplace transform of this function u_a(y)\frac{\partial c(t)}{\partial t} ... Jun19-14 04:32 AM ptrinka 3 1,911