Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question related to PDE y(z_x)+x(z_y)+z=y

  1. Feb 27, 2009 #1
    To solve the PDE:
    y(z_x)+x(z_y)+z=y

    Use Method of characteristics
    a=y
    b=x
    d-cz=y-z

    Thus
    dx/y=dy/b=dz/(y-z)

    Taking first and second term
    xdx=ydy
    x^2-y^2=A
    x=sqrt(y^2+A)

    My question is, at this stage of the calculation, must we account for a negative constant A such that
    x=sqrt(y^2-A)
    and if not why not?

    Thank you
     
  2. jcsd
  3. Feb 27, 2009 #2
    To be honest I'm not familier with the method.

    Is it not that your x and y are the independent variables? So what is the domain for the solution function. A is just a constant. It can be positive or negative. I think!
     
  4. Feb 28, 2009 #3
    Anyone else!?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Question related to PDE y(z_x)+x(z_y)+z=y
Loading...