bobmerhebi
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Homework Statement
Use the appropriate substitution to solve the following D.E.: -ydx + (x + \sqrt{}xy)dy = 0
Homework Equations
y = ux
The Attempt at a Solution
y = ux implies dy = udx + xdu
so -xudx + (x + x\sqrt{}u)(udx + xdu) =0
we then get after some simplificaion: xu\sqrt{}u dx + x2 (1 + \sqrt{}u)du = 0
so (1/x).u\sqrt{}udx + (1 + \sqrt{}u)du = 0
hence dx/x + du/(u\sqrt{}u) + du/u = 0
now we have after integrating: lnx + lnu - 2/\sqrt{}u = c1
substituting bk u= y/x we have: ln x + ln (y/x) - 2\sqrt{}x/\sqrt{}y = c1
ln x + ln y - lnx - 2\sqrt{}x/\sqrt{}y = c1
so ln y - 2\sqrt{}x/\sqrt{}y = c1
here i got stuck. i couldn;t continue although i know that the answer should be : 4x = y(ln|y| - c)2
need help in this please. my process is right isn't it? how should i continue?