Second order Definition and 570 Threads

  1. M

    System of linear second order differential equations

    I think I know how to solve \frac{d\vec{x}}{dt}= A \vec{x} where A is a constant nXn matrix. We just compute the eigenvalues and the corresponding eigenvectors. But how do we solve \frac{d^2\vec{x}}{dt^2}= A \vec{x} Can we say straight away that the solution is...
  2. S

    Second order differential equation

    Homework Statement find the general solution to the second order ode: x4y''+2x3y'+y=0 Homework Equations using Euler's method The Attempt at a Solution assume that the solution is y=xa then y'=axa-1 and y''-a(a-1)xa-2 substituting these into the ode: a(a-1)xa+2axa+xax-2=0...
  3. K

    Distance between two second order maxima

    Homework Statement Monochromatic light strikes a diffraction grating at normal incidence before illuminating a screen 1.99 m away. If the first-order maxima are separated by 1.36 m on the screen, what is the distance between the two second-order maxima? Homework Equations I think these...
  4. S

    Require help for the solution of second order differential equation.

    Dear Friends i am lookin g for the solution for second order differential equation. will anyone please help me to solve this problem.
  5. S

    A second order nonlinear ODE? Whoa

    Homework Statement I'm not sure if this is actually solvable, or a typo on my homework... but here's the problem in question: Solve the ODE: \frac{d^{2}y}{dt^{2}} + t^{2} \frac{dy}{dt} + y^{2} = 0, y(0)=0, y'(0)=0Attempt at solution I've been stumped on where to even start with this one, but...
  6. L

    Non-linear second order equation

    I am not able to find the general integral of the following non-linear 2nd order equation: y^2 y'' + a y^3 - b = 0 in which: y = f(x) 0 < a <= 1, is a constant b > 0 , is a constant.
  7. G

    Second Order Homogeneous Eq's, Auxiliary Eq for complex roots - Help

    Hi I'v got a maths exam on Tuesday for my 2nd year of chemial engineering. Been going through a past paper and have been going over 2nd order homogenous DE's Im at the stage of calculating the roots (wether repeated or 2 distinct roots) I take the easy path like so: E.g m2 + 4m + 4 =...
  8. R

    Second order linear differential operator

    Homework Statement Suppose that L is a second order linear differential operator over the interval J, that f is a function defined on J, and that the function v has the property that Lv = f on J (a) Show that if y = u + v and that Lu = 0 on J, then Ly = f on J (b) Show that if Ly = f on...
  9. M

    Finding the Second Solution to a Homogeneous Second Order DE

    Homework Statement 4xy'' + 2y' + y = 0 2. The attempt at a solution In class, we were given that y1 = c1Cos(\sqrt{}x). We then used reduction of order to figure out the other solution Yet, I've been trying to figure out, is how do you get y1 in the first place? To me, it doesn't...
  10. A

    Second Order Numerical Integration w/ Neumann Boundary Conditions

    I hope this is the right place to post this question. I'm trying to figure out how to run a numeric integration for a nonlinear second order ODE with Neumann B.C. I've started programming up Runge Kutta 4, but clearly without a boundary condition on the function, but only on its derivative...
  11. I

    Second order differential eq problem (from a calc2 class)

    Homework Statement y''+16y=9xe^(4x) y(0)=0 y'(0)=0 find the solution, y(x) to the differential equation The Attempt at a Solution I found the particular solution to the right side of the equation, which is correct, yp= .28125x-.0703125e^(4x) For the left hand side of the...
  12. M

    Solving Second Order Linear ODE with Parabolic Cylinder Functions

    Can anyone help me to solve the following second order linear 'ODE' for V(x,s,t): \frac{\partial^2 V(x,s,t)}{\partial s^2} = g(s) V(x,s,t) where g(s)=\frac{a^2}{B^4}+\frac{s^2 w^2}{B^2}. Here, a, b and w are (real) constants.
  13. M

    How Do You Solve Autonomous Second Order ODEs Like y'' = f(y)?

    Hi All, I was looking for the general solution of an equation as y(x)'' = f (y), and found the attached document on the web. It presents the solution in a way which I am not sure I understand. I tried to look at the trivila example y'' = - y, solution y = sin (x), but I am struggling in...
  14. B

    Second order differential equations and analog computers

    Hey everyone, I've been doing some experiments with analog computers to further my knowledge of op-amps (and second order differential equations!) This is more of a mathematical question than an electrical engineering question, so I thought I'd ask it in this section. I'm looking for some...
  15. A

    Terms of second order and fourth order what does this MEAN?

    Terms of "second order" and "fourth order"...what does this MEAN?! I am reading the paper written by Born and Oppenheimer that explains the development of the Born-Oppenheimer approximation. The paper contains the following cryptic (to me) statement: "The nuclear vibrations correspond to terms...
  16. G

    Differential equation of second order

    I would very much appreciate if anyone can help me with this problem. I got stuck at the end. I have to find 1.the complementary function, particular integral and the general solution. 2. find complete solution when t=0, q=0, dq/dt=0. -equation...
  17. M

    Solving second order PDE by separation of variables (getting 2 ODE's)

    Hi all, For my thesis I would like to solve the following second order nonlinear PDE for V(x,\sigma,t): \frac{1}{2}\sigma^2\frac{\partial^2 V}{\partial x^2}+\frac{1}{2}B^2\frac{\partial^2 V}{\partial \sigma^2}+a\frac{\partial V}{\partial \sigma}=0, subject to the following boundary...
  18. J

    Second order initial value problem

    Homework Statement Solve the initial value problem y" = 2x - y' , y'(0) = 1 , y(0) = 0 I know this is probably a simple problem but I don't have a book for the class yet and the teacher didn't really cover this material in class but we still have homework due on monday so i need to figure...
  19. F

    First and second order partial derivatives

    Hello, I was wondering if I could get some help with a question I have. Homework Statement We are asked to find the first and second order partial derivatives of f(x,y) = x^2 - y^2 - 4x^2/(y - 1)^2 (sorry, I don't know how to write this in latex). I am not really sure how to get started...
  20. B

    Solving a Second Order ODE with V(t) = -Q/C

    Homework Statement Question and part 1 as above. The second part involves solving this equation where L = 8R^2 C. The system is kept in steady state by maintaining V(t) = -Q/C (constant). V(t) is then set to 0 at t=0. It also says "Note that V(t)=0 for t>0 and that appropriate initial...
  21. Fredrik

    Missing Terms in 3.11: Investigating Second Order Terms

    Top of page 69. I get six second order terms. Two of them cancel. Two are the ones on the right of 3.11. The other two involve KμKμ and KνKν. Why are there no such terms on the right of 3.11? I'm probably just missing something painfully obvious.
  22. N

    Splitting a second order PDE into a system of first order PDEs/ODEs

    In my research, I'm using a modified version of the wave equation: \[ c^2 \left( {\frac{{\partial ^2 p}}{{\partial x^2 }} + \frac{{\partial ^2 p}}{{\partial y^2 }}} \right) = - \tau c^2 \left( {\frac{{\partial ^3 p}}{{\partial t\partial x^2 }} + \frac{{\partial ^3 p}}{{\partial...
  23. M

    Proof of second order derivative

    How to prove that y''=d2y/dx2 if y=f(x)
  24. S

    Solving 2nd Order ODE: y''+(1/x)y'=0

    Homework Statement find the general solution to the ODE: y''+(1/x)y'=0 Homework Equations The Attempt at a Solution I put this in the following form: y''=-(1/x)y' integrated both sides: y'=-ln(x)y +C I think i made a stupid mistake but i can't figure out what it is. Any help...
  25. T

    Second order partial derivatives

    Homework Statement if z= f(x) + yg(x), what can you say about zyy explain? Homework Equations The Attempt at a Solution z= f(x,yy) zyy = d/dy (dz/dy) d(partial derivative)
  26. T

    Second Order ODE - Variation of Parameters

    Homework Statement Find the general solution of the following diff. eqn. y''(t) + 4y'(t) + 4y(t) = t^(-2)*e^(-2t) where t>0 Homework Equations General soln - Φgeneral(t) + Φparticular(t) Wronskian - Φ1(t)Φ22'(t) - Φ2(t)Φ1'(t) The Attempt at a Solution I'm solving by...
  27. T

    Solve Second Order ODE: Find a Values for Zero Tendency

    Homework Statement Find all values of a for which all solutions of y''(x) + (a/x)y'(x) + (5/2)y(x) = 0 tend to zero as x tends 0+ and all values for which all solutions tend to zero as x tends to + Homework Equations The Attempt at a Solution I am not even sure where to being with this...
  28. K

    Second order ODE solution for this system?

    second order ODE solution for this system?? hello guys, I am wondering if what is the analytical solution for this system? can we solve it as a mass-spring-damper system? thanks for your helps. the rectangular part is removed from the disk. http://img3.imageshack.us/img3/3610/odev.th.jpg
  29. D

    Identifying Spectra Using First & Second Order Lines

    I know there are many ways to identify the spectra but, what are the advantages and disadvantages of using the first and second order lines to identify spectra? Please Help! If u don't want give me answer then suggest me some links. Thanks
  30. E

    Contour diagram and second order of partial derivative

    Homework Statement The following contour diagram represents the function z = f(x,y) http://img15.imageshack.us/img15/9059/contour.th.jpg (a) Is z an increasing or decreasing function of x? I'd say it's increasing as it goes towards the x-axis the contour lines value goes down (b) Is z...
  31. P

    Help solving non-linear second order DE

    could anyone help me with solving this second order differential equation? I am a noob on here so not sure how you get the mathplayer stuff on... so the equation is of the form x'' +ax' + bx^n = 0 (x^n means x to the power n, with a and b constants). i tried substituting x'=u to get a first...
  32. J

    Second Order ODE Using Laplace Transforms

    Little homework problem that I'm beating myself up over... Solve: xy'' - 2y' + xy = -2\cos x Using the method of Laplace transforms... So I do some jiggling and get to: (1+s^{2})\frac{dF}{ds}+4sF(s) = \frac{2s}{s^{2} + 1} To which I find the following solution: F(s) =...
  33. B

    Tips for Solving a 1D Second Order ODE in an Open Channel Experiment

    Hi all, My maths are very rusty and I would need some advice. I have some experimental results obtained in an open channel and got depth-averaged velocity u(y) at different cross-sectional locations y. I tried different models but there is one I don't know how to tackle. The following one...
  34. R

    Non linear second order diff eq

    I'm trying to find a substitution that works for the nonlin diffeq y''+a(y')^2-by=0 Any suggestions?
  35. S

    Solving a Second Order Linear Differential Equation

    Hi, I'm having problems solving this equation; y'' -2y' +3y =0 y(0)=-1 , y'(0)=(root 2) -1 I found the auxiliary equation r^2 -2r +3 = 0 and since b^2 -4ac is less than zero this the case where r1 and r2 are complex numbers. This is as far as I get without getting stuck...
  36. Y

    How Does a Second Order High-Pass Filter Create Energy at Cutoff Frequency?

    Hey guys, I have a question about the Bode diagram of a second order high-pass filter (one with both a capacitance and an inductance). The Bode-diagram of the amplitude looks like this. http://dave.uta.edu/dillon/pspice/images/pst07g.jpg Here, the cutoff frequency is equal to about 10 kHz...
  37. V

    Second order nonlinear differential equation

    hi, i am facing problem in solving the following differential equation. help me. y''+ayy'+b=0, where y is a function of x, 'a' & 'b' are constants. i have tried substituting y'=u, which implies u'=u*dy/dx, these substitution change the equation to first order but i found no...
  38. E

    General solution of a second order nonlinear DE

    1. Homework Statement + relevant equations I have to solve http://home.vs.moe.edu.sg/linl/eqn1.gif sigma, pinfinity, rho, N are constants. To make things easier for us, we are allowed to treat T as a constant. 2. The attempt at a solution Treat T as constant...
  39. C

    Understanding Second Order PDEs: Explaining the Unit Tangent to a Curve

    Hi In my lecturer's notes he describes the unit tangent to a curve y=Y(X) as (i + Y'(X)j)/[(1+[Y'(X)]^2)^(0.5)] in an introduction to second order PDEs I'm a bit confused by this. Where did it come from? Can anyone explain Thanks
  40. S

    Matlab: Solving two second order differential equations

    Homework Statement Write a function and solver for the chaotic motion of stars in a galaxy Initial conditions: x at time zero = 0 velocity of x at time zero = 0.3 y at time zero = 0 velocity of y at time zero = 0 Time period 2 to 200 with an interval od 0.02 Homework Equations...
  41. J

    Second Order Seperable Differential Equations

    Hello and thanks to all who read this. I'm trying to teach myself applied mathematics, specifically (simple) differential equations. I've been solving them all fine, so far, but now I've come across second order DE's with a squared term, and I can't seem to get the right answer. I'll give...
  42. Z

    Linearizing a second order non-linear equation

    Homework Statement I am modeling a set of equations for a protein network. It is a feedback loop between 2 proteins. I have gotten the differential equations for this model and plan on doing an extended Kalman Filter to estimate the levels of protein in real time. However, I am having...
  43. E

    Please help Need solution to Second Order nonlinear DE

    Does anyone know how to solve the following Non-linear, second order, differential equation? A*y" + B*(y')^2 = F(t) + C where A, B, & C are constants **please note, in case the above notation isn't clear, the y' term is squared which is what makes it non-linear. Also, F(t) is time...
  44. A

    Second Order Homogeneous Differential Equation.

    I would very much appreciate if anyone can help me with this problem; I have approached it from many different angles to no avail. The position x(t) of a particle moving along the x-axis is governed by the differential equation: x'' + kx' + (n^2)x = 0 , and initially x(0) = a, x'(0) = u...
  45. V

    Power series solution to a second order o.d.e.

    Homework Statement Find the terms up to x^5 in the power series solution of the following equation y''=(1+x^{2})y Homework Equations Power series, sum from 0 to infinity y=\sum a_{n}x^{n} The Attempt at a Solution At first I just differentiated each term separately and...
  46. T

    Solving Second Order Differential Equations with Constant Coefficients

    Homework Statement I've completed this question but I don't think I've got it right. It's from a 2008 June FP1 further maths paper. There is a second part to the question I don't understand which I will post after I know I have got this part right :) Find, in terms of k, the general...
  47. K

    Why is the solution for a second order ODE -m_{l}^{2} e^{im_{l}\phi}?

    Can someone explain to me why the solution of \frac{d^{2}\Phi (\phi)}{d\phi^{2}} = -m_{l}^{2} is \Phi = e^{im_{l}\phi}?
  48. R

    Second Order Differential Equation

    This is the question word for word: a) Solve the initial value problem: x'' + x = 2cos(\omega t) ; x(0) = 0 ; x'(0) = 0 ; \omega != 1 b) repeat but with \omega = 1 c) use the trigonometric identity: cos(\alpha) - cos(\beta) = -2sin(\frac{\alpha + \beta}{2})sin(\frac{\alpha - \beta}{2})...
  49. I

    Second Order Differential Equation Help

    Homework Statement A 2-\mu F capacitor is charged to 20 V and then connected across a 6-\mu H inductor forming an LC circuit. (a) Find the initial charge on the capacitor (b) At the time of connection, the initial current is zero. Assuming no resistance, find the amplitude, frequency and...
  50. R

    How to Solve a First and Second Order ODE for y(x) and u=dy/dx

    The Problem You are given: http://img530.imageshack.us/img530/4468/88346476ca9.jpg Where http://img408.imageshack.us/img408/209/53113174nt5.jpg is constant (taken as B). a) Differentiate both sides to produce a second order ODE for y(x) b) Show that it can be written as a first order ODE...
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