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!

Nonlinear DE reduction

  1. Jun 23, 2012 #1
    1. The problem statement, all variables and given/known data

    [itex]\ddot{y} = - \dot{y} - y -sin(y)[/itex]

    2. Relevant equations
    3. The attempt at a solution
    to reduce the order I need to find a solution y1. it seems to me the only obvious solution is y1 = 0 but i can't use this to do a reduction can i
     
  2. jcsd
  3. Jun 23, 2012 #2
    Hi sunrah! :smile:

    You should be able to reduce the given DE to first order by substituting [itex]\frac{dy}{dx}= t[/itex]
     
  4. Jun 23, 2012 #3
    indeed, thank you!
     
  5. Jun 23, 2012 #4

    I hope you didn't write [tex]\frac{d^2y}{dt^2} = t'[/tex] :wink:
     
  6. Jun 23, 2012 #5
    i used
    [itex]\frac{d^{2}y}{dx^{2}} = \frac{dt}{dx}\frac{dy}{dy} = t\frac{dt}{dy} [/itex]
     
  7. Jun 23, 2012 #6
    Yep, perfect! :approve:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Nonlinear DE reduction
  1. Is this DE nonlinear? (Replies: 5)

  2. Nonlinear DE (Replies: 11)

Loading...