# Differential Equations

- An equation involving derivatives of a function or functions. Solving ODE and PDE
 Meta Thread / Thread Starter Last Post Replies Views Views: 4,878 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 30,360 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 95 138,901 According to the confluent hypergeometric equation \frac{d^2}{d x^2} y + \left(c - x \right) \frac{d}{d x} y - a y =... T 10:21 AM Domdamo 4 2,231 Hello I'm struggling with well-known problem of finding shortest path between two points on a sphere using calculus... T 06:56 AM Blazejr 2 125 With $$H = \alpha \left(x^{2}\partial_{x} - x \partial_{x} \right) + \beta\left(x \partial_{x}^{2} -... T 02:18 AM Strum 0 74 sorry for spamming the boards with all these questions lol- i promise this is my last post regarding n body problems.... Y 09:35 PM bluntwcrackrap 3 210 I was reading this interesting article on different varieties of roller coaster loops, and I know nothing about... Sep14-14 12:50 PM FactChecker 2 139 Heya folks, I'm currently pondering how to decide whether a function has an inverse Laplace transform or not. In... Sep13-14 10:51 PM qftqed 0 127 Hi everyone, I need some help to solve this differential equation. The question states "Use the perturbation or... Sep12-14 02:05 PM Johnmm 11 390 Hello, First I'd like to state that I understand how to show that a relation defines an implicit solution of a... Sep11-14 06:37 PM _N3WTON_ 1 96 For each epsilon greater than 0, show that the differential equation x'=x^2-1-cos(t)-epsilon has at least one periodic... Sep11-14 02:10 PM jambaugh 1 137 I took an introduction to ODEs course this past spring semester. It always bothered me where this thing came from. I... Sep10-14 05:52 PM priti2014 13 403 the force field trajectory calculator worked pretty good, so i decided to step it up and solve the famous n body... Sep10-14 01:49 PM bluntwcrackrap 2 226 Hi, I'm an engineer who uses a lot of finite-element software for doing multiphyics modeling. I've been learning a... Sep9-14 07:11 AM NumericalFEA 10 578 Hi, I want to solve the following diffusion equation: (d/dt) C(r,z,t)=D*∇^2 C(r,z,t) where C is the... Sep8-14 07:26 PM nazmulislam 2 159 Hello, it is known that given a certain recurrence relation that describes a sequence of numbers, it is often... Sep8-14 11:35 AM mnb96 0 88 Hello, I was just after an explanation of how people get to this conclusion: Say you are looking at the... Sep8-14 11:08 AM Gwinterz 3 408 Hi, I was just wondering if : (y^2 - 1)*dx/dy + x = 0 In this case, x is the dependent variable. Is linear?... Sep8-14 07:36 AM HallsofIvy 2 136 I'm trying to do some refreshing of differential equations featuring damped systems. Specifically, I have a question... Sep8-14 07:24 AM HallsofIvy 1 109 In most textbooks I've read and programs I've work with, differential equations are normalized (made dimensionless)... Sep7-14 08:38 PM X89codered89X 3 288 Hi all , I would like to solve the following partial differential equation. (∂α/∂t)=G *(a'-a) I attached the... Sep7-14 09:47 AM bigfooted 4 206 I was wondering if there is a way to get specific numerical values for the following differential equation: f'(x)+... Sep6-14 05:38 AM DMT69 5 164 When talking about ordinary (real) linear differential equations with constant coefficients the idea is that we are... Sep5-14 06:59 AM HallsofIvy 1 173 I have a linear time-varying linearly perturbed ODE of the form: \dot{x} = x where A(t) is a bounded... Sep3-14 04:33 PM dmytro 1 135 Im writing a program that calculates the trajectory of a particle in an arbitrary force field. the force field is a... Sep3-14 02:39 PM bluntwcrackrap 5 334 I want to model a Differential Equation for a projectile motion under 2 forces (gravity and wind) So, what I have... Sep3-14 01:08 PM Feeh 2 218 I am learning how to solve 1st order linear ODEs using the integrating factor.However, I run into confusion at the... Sep3-14 08:08 AM HallsofIvy 4 178 I had a brief question regarding SDEs. Typically, I've seen models like the Ornstein-Uhlenbeck process that generally... Sep3-14 12:22 AM Apogee 6 181 Firstly, if this is an inappropriate forum for this thread, feel free to move it. This is a calculus-y equation... Sep2-14 10:13 PM jasonRF 2 230 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 2 239 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 2 195 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 13 515 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 2,132 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 1,353 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 2 270 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 3 263 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 4 337 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 1 201 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 8 391 Hi, while solving differential equations problems we have to sometimes use absolute value while taking an integral of... Aug13-14 11:30 AM HallsofIvy 3 279 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 1 388 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 7 298