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Differential equations

  1. Oct 23, 2009 #1
    i just started a course in differential equations, and this question was in the homework that i got, im not sure we learned how to solve it but maybe i am meant to know.

    xy' + y = sqrt(x-1)

    up until now all i have been able to solve is equations which i can bring to a form of dx/x +dy/y = 0 or something like that

    because this question has 3 parts i havent been able to get F(x)dx + F(y)dy=0

    xy' + y = sqrt(x-1)

    x*dy/dx + y =sqrt(x-1)

    dy/y + x*dx = sqrt(x-1)*dx/y

    dy/y = (sqrt(x-1)/y - x )dx

    now i cant integrat this because on the right i have y as well as x and cannot get rid of it
  2. jcsd
  3. Oct 23, 2009 #2
    Looks like you are familiar only with separable differential equations. Have you learned about integrating factors? That's what you need to solve this DE.
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