1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: 2nd Order inhomogeneous ODEs

  1. Mar 30, 2010 #1
    1. Using the complementary function and particular integral method find the solutio of the differential equation.

    d2y/dx^2 + 3 dy/dx +2y = 20cos2x

    Which satisfies y(0) = 1 y'(0) = 0



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 30, 2010 #2
    there are different ways to solve this differential equation.
    I know you can solve it with the method of undetermined coefficients OR Variation of Parameters.
     
  4. Mar 30, 2010 #3
    I have already found the complementary function to be:

    y = Ae^(-t) + Be(-2t)

    Im just not sure how to find the particular integral!
     
  5. Mar 30, 2010 #4

    Mark44

    Staff: Mentor

    Try yp = Ccos(2x) + Dsin(2x) for your particular solution.

    Minor note: The independent variable should be x, not t, since x is the independent variable in your differential equation.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook