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First Order, Non-Linear DE - Not Seperable

  1. Jul 15, 2012 #1
    Hello, I'm studying for a test and this is a question on a practice test...

    cos(x)+y^2+(2yx-1)y'=0


    I can't separate the variables (it's not homogeneous, either), this isn't exact and bernoulli won't work...

    dy/dx=-cos(x)/(2yx-1)-y^2/(2yx-1)

    I changed the equation so it would look like this but I can't simplify it any more than that and I can't just take the integral of it here...If anyone could give me some help with this problem it would be much appreciated. Thanks!
     
  2. jcsd
  3. Jul 15, 2012 #2
    Looks like an exact equation, if it's on your test you should know how to solve it. That said, it doesn't look like the solution is anything obvious so you'll have to go through the usual P = df/dx and Q = df/dy
     
  4. Jul 15, 2012 #3
    Oh you're right, thanks!
     
  5. Jul 15, 2012 #4
    Hi !

    cos(x)+y²+2yxy'-y'=0
    cos(x)+(x y² -y)'=0
     
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