1. Not finding help here? Sign up for a free 30min 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!

Linear DE help.

  1. Nov 29, 2004 #1
    I've got a linear DE here,

    [tex] (x + 4y^2) dy + 2y dx =0 [/tex]

    I've tried to put it in the general form of a linear equation, and I would get,

    [tex] \frac {dy}{dx} + \frac {2y}{x+4y^2} = 0 [/tex]

    but I have problems isolating the x, so that I would get the [tex] P(x) [/tex] in the general form.
     
    Last edited: Nov 29, 2004
  2. jcsd
  3. Nov 29, 2004 #2

    AKG

    User Avatar
    Science Advisor
    Homework Helper

    This doesn't make sense. If "DE" stands for "differential equation" then no, you don't have a DE here.
     
  4. Nov 29, 2004 #3
    ^ sorry, its supposed to be equals to 0, i forgot to add that...
     
  5. Nov 29, 2004 #4

    Hurkyl

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Think outside the box for a moment. There's a very easy way to turn this into an ODE.
     
  6. Nov 30, 2004 #5

    James R

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Your D.E. is not linear, either.
     
  7. Nov 30, 2004 #6

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    The way you have written it
    [tex] \frac {dy}{dx} + \frac {2y}{x+4y^2} = 0 [/tex]
    it is not linear.
    However, you can write
    [tex] (x + 4y^2) dy + 2y dx =0 [/tex]

    as
    [tex]\frac{dx}{dy}= -\frac{x+4y^2}{2y}= -\frac{1}{2y}x- 2y[/tex]
    which is a linear d.e. for x as a function of y.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Linear DE help.
  1. First order Linear DE (Replies: 2)

  2. Second order linear DE (Replies: 3)

  3. Non-linear DE's (Replies: 4)

  4. 2nd order Linear DE (Replies: 1)

  5. Is this DE linear? (Replies: 3)

Loading...