1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Find a particular solution that satisfies the intial condition

  1. Nov 24, 2009 #1
    1. The problem statement, all variables and given/known data
    2xy'-ln x2=0 y(1)=2

    2. Relevant equations

    3. The attempt at a solution
    2x(dy/dx)-ln x2=0

    I think I'm suppose to separate variables and then integrate next but I'm not sure.
  2. jcsd
  3. Nov 24, 2009 #2


    Staff: Mentor

    Yes, this is a separable differential equation.

    You should use the fact that ln(x2) = 2ln(x).

    2x*dy/dx = 2 ln(x)
    [tex]\Rightarrow~dy~=~ \frac{ln(x)}{x}dx [/tex]

    Now integrate both sides. Don't forget the constant of integration, which you will determine from your initial condition, y(1) = 2.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook