# Differential Equations

- An equation involving derivatives of a function or functions. Solving ODE and PDE
 Views: 8,619 Announcement: Two free ways to get Gold Membership! Jan17-12 Meta Thread / Thread Starter Last Post Replies Views 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 25,468 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 95 120,080 Hi, it is easy solving these PDEs with the idealized homogeneous BCs they throw out in class, but I am having some... Y 11:07 PM womfalcs3 2 150 Hello, does anyone knows the Integral of (dx)^2 Excuse my english, I hope I had make myself clear, thanks Mar8-14 07:08 PM micromass 6 245 I was wondering if somebody could clear up some confusion I have regarding this. I've been going over the... Mar8-14 06:56 AM jellicorse 2 92 Hello,Iam facing a problem with using FindMinimum Function .Can any body help me ? First I used FindRoot fuction to... Mar8-14 03:45 AM Reem Hashem 0 71 Notice that, when solving second-order linear homogeneous constant-coefficient ODEs, the classic linearly independent... Mar6-14 02:18 PM lurflurf 1 179 By a fortuitous mistake in copy/pasting, I happened across this system. It exhibits very chaotic behavior for some... Mar6-14 08:40 AM TylerH 1 105 Hello, As of recently, I've been working with Laplace transforms and have a question about their relationship to... Mar5-14 05:18 PM jaytech 5 281 Hello, I am doing some physics and I end up with this PDE: \frac{\partial q(x,y,t)}{\partial t} = -(x^2 +... Mar5-14 07:50 AM Shyan 3 172 Hello. I have a set of ODE where 1) \frac{dv_x}{dt}=\frac{q(t)B}{m}v_y 2) \frac{dv_y}{dt}=\frac{q(t)B}{m}v_x 3)... Mar4-14 05:47 PM Eloise 5 222 Consider a smooth map ##F: M \to N## between two smooth manifolds ##M## and ##N##. If the pushforward ##F_*: T_pM \to... Mar4-14 11:16 AM center o bass 0 83 Why all jacobi theory and all ellipitc integrals is based in ##\Delta(\theta) = \sqrt{1-m \sin(\theta)^2}## ? You... Mar1-14 09:54 AM Jhenrique 0 170 I have derived these pair of coupled diff equations for U_1 (r) and U_2 (r): r^2 \dfrac{d^2 U_1 (r)}{dr^2} + r... Feb27-14 01:46 PM julian 2 205 Hi everyone, I am trying to find analytical solution (at least approximated) for the following equation: ... Feb26-14 10:25 PM Kvad 0 178 I believe this is an error minimization problem so I am trying to solve the following equation Min((∑ ( (S(t) -... Feb26-14 03:43 PM AlephZero 4 214 The Greens function for the wave equation satisfies the differential equation \square G(x,x') =... Feb26-14 10:35 AM hilbert2 1 150 Hi, Are there any open source C or Fortran libraries for solving 3D Poisson'sequation on an irrefular domain? I'm... Feb26-14 01:50 AM AlephZero 2 169 Hi guys, I have problem in constructing the corresponding differential equation for a markov model: Given a markov... Feb25-14 05:21 PM phyalan 0 117 It is known that:\mathcal{F}\{f\ast g\}=\mathcal{F}\{f\}\mathcal{F}\{g\}\mathcal{F}\{f... Feb25-14 12:40 PM Jhenrique 4 147 This is the definition for the inverse of the laplace transform: ... Feb25-14 09:10 AM Jhenrique 0 121 I can't see the proof clearly. Gradient dot = d/dt = n * t^(n-1) * I don't see... Feb24-14 04:32 PM clairaut 2 185 Is there a single, general, solution guaranteeing method that can be applied to any first degree first order... Feb24-14 12:53 PM bigfooted 5 215 I'm confused finding a solution (numerical integration is ok) for the following model: ... Feb24-14 05:51 AM WLamers 1 204 Looking at the solutions to these initial value problems, I am very confused as to how the highlighted steps are... Feb23-14 06:14 PM annas425 0 153 Hello guys, I would like to ask some questions regarding my coursework, which is about 2nd ODE and multivariable... Feb23-14 02:54 PM LCKurtz 4 254 Let y be a solution of the di®erential equation, \frac{dy}{dx}=\frac{y-1}{x+1} such that y(0)=0; Then y(1)... Feb20-14 10:59 AM pasmith 1 167 Hi there. As the title says im kinda stuck here. My problem is I dont know how I get to the solution that Mathcad... Feb20-14 07:05 AM Autosug 1 176 When solving a Fourier Series, you can run into things that have the following structure. cos(n*pi) cos(n*2pi) ... Feb19-14 10:14 PM HallsofIvy 1 194 AP Physics student here, I'm working on a problem that takes into account air resistance, where something is thrown up... Feb19-14 06:51 PM Chestermiller 1 194 I am looking for a general expression for an integrating factor μ(x,t) to solve the following diffential equation for... Feb19-14 04:53 PM tom.stoer 9 248 Hello, I had a question about the method of undetermined coefficients for solving ODE's. I understand it is only... Feb15-14 06:18 PM AlephZero 4 376 I have the ODE x''(t)+\frac{k}{m}x(t)=0. Given that the solution is of the form sin(ωt+ø), I plug this form into... Feb14-14 01:04 PM PeroK 3 258 Hi, I would like to find the inverse Laplace transform for 11/(s^2+16)^2 I have tried to expand it using the... Feb14-14 12:15 AM lurflurf 1 207 This is a request about the second order differential equation ... Feb12-14 11:56 AM jimmy neutron 0 226 So figuratively, I'm trying to win a nuclear war with a stick. :rofl: I did not take any course in PDEs, I just... Feb11-14 05:43 AM maka89 1 360 Hi, I want to solve the infinite time optimal control problem: J(x, u, t) = \int_t^\infty (x^TQx+u^TRu)\,dt ... Feb11-14 05:31 AM oaksoy 0 196 Hi! I am trying to make a one-dimentional simulator for two-phase flow. I am going to use the finite volume method,... Feb11-14 05:21 AM maka89 0 204 I'm working on manipulation and moving deformable objects by use of a robot with a 2-finger gripper. I would like to... Feb11-14 04:03 AM Liferider 4 235 Hi fi you look at quesiotn 16b in the following link they try to find dE/dx. they use the chain rule. the chain... Feb10-14 09:41 AM vanhees71 1 189 Hi, I would like to convert back this descritized equation(which was done by 3step,runge kutta) to its original PDE... Feb9-14 07:27 PM omid88 0 219 Hello, When I have the differential equation \frac{dY(x)}{dx} = -k^2 Y(x) The solution is of course harmonic... Feb9-14 04:45 PM AlephZero 4 264