# Differential Equations

- An equation involving derivatives of a function or functions. Solving ODE and PDE
 Meta Thread / Thread Starter Last Post Replies Views Views: 2,414 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 30,172 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 95 138,495 Hello, I watched a lecture by Leonard Susskind, in which he said that a differential is so short that when you... Apr29-14 09:49 AM dauto 15 998 If a repeated integral can be expressed how an unique integral: ... Apr28-14 03:51 PM Jhenrique 7 384 What are the applications of Adams-Bashforth-Moulton Method for O.D.E.'s in the real world? How we could utilize this... Apr28-14 01:08 PM iwan89 5 398 I was thinking about some form of classify all kinds of equations and system of equations. And the better... Apr25-14 01:18 PM micromass 6 371 Hello, I have trouble solving the following differential equation. I am trying to learn how to solve that form... Apr25-14 08:52 AM vanhees71 3 454 Hi, I'm an engineer who uses a lot of finite-element software for doing multiphyics modeling. I've been learning a... Apr22-14 10:31 PM the_wolfman 9 481 Hello I was recently working on a problem where I had to solve the differential equation in the title ( where y is a... Apr22-14 12:48 PM the_wolfman 2 305 I would like to model rain hitting a surface and then running off of the surface. The surface would be a square, such... Apr21-14 07:07 AM HallsofIvy 1 457 I'm having a hard time understanding Green's functions which have been introduced quite early on in the course, and... Apr20-14 12:49 AM chipotleaway 2 350 I'm not sure if this is particularly important, but so far through my studies I've only encountered DE with two... Apr20-14 12:21 AM micromass 2 309 For a system of linear differential equations with constant coefficients with known initial conditions an analytical... Apr19-14 10:26 AM Mark44 1 311 I'm trying to analyze the following Ito stochastic differential equation: $$dX_t = \|X_t\|dW_t$$ where X_t,... Apr18-14 06:57 PM Only a Mirage 2 339 Hi everyone, I'm taking the Differential Equations for the first time, and I want to know the most helpful textbook... Apr18-14 08:12 AM Bill_K 2 376 When I multiply out the first line I end up with an extra (dA/dx)*(dσ/dx). Can someone please show me how i get from... Apr17-14 04:44 PM Bill_K 1 286 In this video at around 9:00 , Carl Bender demonstrates a method of solving y''+a(x)y'+b(x)y=0. ... Apr17-14 09:28 AM chipotleaway 2 266 Definition: ##f(x+k) = \exp(k \frac{d}{dx}) f(x)## So I thought, how take advantage this definition? Maybe it be... Apr17-14 08:19 AM Jhenrique 2 329 Hello I am trying to solve this ODE dx/dt=(f(x)+g(t))^(1/2) I have been recalling what I learn in my ODE... Apr16-14 02:16 PM MathematicalPhysicist 8 435 I tryied make the convolution product between x² and x³ by ##\int_{- \infty}^{+ \infty} f(u) g(x-u) du## and the... Apr14-14 06:20 PM micromass 5 377 I have a differential equation to solve below on the motion of an object oscillating in water with a restoring force... Apr14-14 11:34 AM the_wolfman 1 314 Hello, PF! As I was reading my P-Chem textbook, I noticed most thermodynamic equations involve partial derivatives,... Apr13-14 08:18 PM Mark44 3 362 I know that the standard definition for a slope field is ##\frac{dy}{dx} = f(x, y)##, but and if the equation given is... Apr13-14 04:08 PM HallsofIvy 1 273 f(x,y) = ln(9 - x2 - y2) Domain I got: (x, y) in R2 such that x2 + y2 < 9 How do I find the range from the... Apr12-14 12:09 PM JC3187 6 354 Show that the explicit Runge-Kutta scheme $$\frac {y_{n+1} -y_{n}}{h}= \frac{1}{2}$$... Apr10-14 07:21 PM rickyflair 2 339 If a system of first-order ODEs like ##\frac{d\vec{r}}{dt}=A\vec{r}## have as solution ##\vec{r} = C_1 \exp(\lambda_1... Apr10-14 02:58 PM Jhenrique 9 552 Hi All, I am taking Dynamic Systems and Controls this semester for Mechanical Engineering. We are solving non... Apr9-14 12:40 AM MisterX 1 390 You can give me a good examples where ##\frac{\partial}{\partial x}## is different to ##\frac{d}{dx}## ? Apr8-14 09:12 AM Jhenrique 2 378 Hello I am having some trouble understanding what the difference is between the reference solution and the "true"... Apr7-14 07:36 AM jjr 2 444 Hello guys, suppose we have an eigenvalue problem \left\{ \begin{array}{ll} u'' + λu = 0, ... Apr2-14 10:44 AM AlephZero 6 521 I realized that a PDE of 2nd order can written like: A:Hf+\vec{b}\cdot\vec{\nabla}f+cf=0 \begin{bmatrix} a_{11} &... Apr1-14 09:22 PM Jhenrique 0 338 Hi, I am looking for a solution of \frac{\partial\phi}{\partial t} =... Apr1-14 06:50 AM soni 0 322 Which the difference between diff equations of kind: \frac{dy}{dx} = \exp(x) \frac{dy}{dx} = 1/x and diff equations... Apr1-14 02:22 AM Mark44 8 401 Hello, I have been trying to find an equation to represent the observed angular velocity of any object traveling in a... Mar31-14 08:50 PM bendloewen 3 425 Hello, I'm trying to analyze a system of elastically coupled oscillators, whose masses are all the same, using... Mar31-14 10:51 AM Runei 1 303 Hello, I am doing some physics and I end up with this PDE: \frac{\partial q(x,y,t)}{\partial t} = -(x^2 +... Mar28-14 02:51 PM kosovtsov 4 704 How do we solve a system of coupled differential equations written below? -\frac{d^2}{dr^2}\left( \begin{array}{c}... Mar27-14 11:04 PM Ravi Mohan 2 480 Given a implicit ODE like F(x, y(x), y'(x), y''(x)) = 0, why your explicit form is y''(x) = f(x, y(x), y'(x))? Why a... Mar27-14 12:36 PM micromass 4 432 If we have a constant coefficient second order homogeneous ODE, the way to solve this is to suppose a solution of the... Mar27-14 08:13 AM quasar987 4 404 hello pf! i am wondering if anyone here knows of a geometric, intuitive explanation for the laplace transform? if... Mar26-14 05:34 PM micromass 3 372 I would like to learn this. Can someone teach me? The things like δy2/δ2x and solving for x and y. :rolleyes: Mar26-14 12:37 AM z.js 10 704 I want to solve y''+y'+y=(sin(x))^2 and try to use y=Ae^{ix} but then when I square it I get A^2 e^{2ix} ... Mar26-14 12:26 AM lurflurf 1 333