# Differential Equations

- An equation involving derivatives of a function or functions. Solving ODE and PDE
 Meta Thread / Thread Starter Last Post Replies Views Views: 2,628 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 30,192 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 95 138,534 Im writing a program that calculates the trajectory of a particle in an arbitrary force field. the force field is a... T 02:14 PM bluntwcrackrap 5 170 I had a brief question regarding SDEs. Typically, I've seen models like the Ornstein-Uhlenbeck process that generally... Y 07:42 PM Matterwave 5 121 Firstly, if this is an inappropriate forum for this thread, feel free to move it. This is a calculus-y equation... Y 10:17 AM Greg Bernhardt 1 153 I took an introduction to ODEs course this past spring semester. It always bothered me where this thing came from. I... Y 08:09 AM FactChecker 9 189 Find y(t), the inverse laplace transform of Y(S). Y(S)= 10 U(S)/2 + 2/(s-4) + s/((s+1)(s+2)) - 6/(s-4)^4. ... Aug31-14 03:30 PM white.carbon 0 82 Hello, I was just after an explanation of how people get to this conclusion: Say you are looking at the... Aug28-14 06:31 AM jtbell 2 339 1. why do we need to use shifted unit step function in defining second shifting theorem? 2. why don't we instead... Aug27-14 07:45 AM asitiaf 2 182 hello. I have a matlab skeleton provided because i want to model a distribution with a circular geometry. all in all,... Aug25-14 06:19 AM Strum 2 148 What is the vector space under consideration when we say that a linear differential equation is of the form Dy=f ... Aug24-14 07:30 AM V0ODO0CH1LD 13 453 Is it possible to solve a differential equation of the following form? $$\partial_x^2y + \delta(x) \partial_x y +... Aug23-14 03:55 AM Simon Bridge 2 2,079 For the following problem \frac{dw}{d\theta}=\theta w^{2}sin(\theta^{2}), w(0)=1 I am not able to obtain the... Aug21-14 03:12 PM rjr 4 1,305 Hi friends i am trying to solve heat equation for a single time domain,with Finite Difference Method. I wrote a... Aug20-14 02:52 PM Strum 2 215 Suppose all second partial derivatives of F = F (x, y) are continuous and F_{xx} + F_{yy} = 0 on an open rectangle R. ... Aug19-14 10:47 AM Medicol 3 221 Greetings all ! This is my first post on the forum, so please kindly let me know if I am not asking a proper... Aug18-14 03:12 PM atto 4 279 I want to solve the following differential equation using matlab and thus want to plot between x & y.... Aug17-14 04:27 AM da_nang 1 157 hi pf! ok, so my math text for PDE's states the following theorem:$$f(x) = \sum_n a_n \phi_n (x)$$for "nice... Aug14-14 11:25 PM Shyan 8 335 Hi, while solving differential equations problems we have to sometimes use absolute value while taking an integral of... Aug13-14 11:30 AM HallsofIvy 3 217 Hi guys , I'm currently reading a book and I faced this with DEs: In the 5 attached images you'll find the textbook... Aug8-14 11:50 PM Simon Bridge 1 345 Hi everyone, i am trying to solve and program a non linear differential equation in matlab where thermal conductivity... Aug8-14 11:04 PM Chestermiller 7 245 http://www.math.uiuc.edu/documenta/vol-ismp/40_lemarechal-claude.pdf I don't understand why we use theta for... Aug8-14 07:32 AM HallsofIvy 1 222 Here's the problem: Find the general solution of x*dy/dx+2y=10x^2. How do I find the answer for this problem on... Aug7-14 07:50 AM Sunfire 2 228 This is a bit counterintuitive to me that the gradient vector is always normal to the level curve and the level... Aug6-14 07:12 AM HallsofIvy 2 222 Hi all, first of all I apologise if my question is not supposed to be in this thread. I am a fledgling mathematician,... Aug5-14 11:22 PM Greg Bernhardt 1 275 Can anybody give me some links for plotting bifurcations online? Aug5-14 11:22 PM Greg Bernhardt 1 379 Suppose we have some partial differential equation for a scalar ##f##$$Df = \rho$$taking values in... Aug5-14 11:22 PM Greg Bernhardt 1 775 does negative divergence of gradient tempearature gives to lalace equation...? -div(∇T) = Aug5-14 07:32 PM SteamKing 1 202 I want to be able to map the position of a planet given initial position, velocity, and acceleration. I know the... Jul30-14 08:21 AM Juan Carlos 2 2,277 Hi!, I'm working on a personal project: Solve the heat equation with the semi discretization method, using my own... Jul30-14 08:08 AM Juan Carlos 2 275 Hey there, I have modeled a propagating wave in a 1D dispersive media, in which square and cubic nonlinear terms... Jul30-14 01:14 AM Strum 2 1,997 How to understand Uniqueness and existence theorem for first order and second order ODE's intuitively? Jul28-14 02:51 PM homeomorphic 3 496 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 1 815 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 1 815 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 2 736 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 4 957 My textbook says that: "A differential equation contains both the function and the derivative of the function" ... Jul22-14 04:31 PM johann1301 3 887 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 2 771 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 2,186 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 3,496 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 2,608 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 1,507