Homogenous Differential Equations (Converting Back into Explicit Form

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SUMMARY

The discussion focuses on solving the homogenous differential equation given by x*e^(y/x) + y dx = xdy with the initial condition y(1) = 0. The solution process involves transforming the equation into a function of v by dividing through by x dx, leading to the equation e^v + v = dy/dx. The user correctly integrates both sides to derive the explicit form y = -x/(ln(cx)), but questions whether applying the initial condition to find the constant c would simplify the solution further.

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Homework Statement



x*e^(y/x) + y dx = xdy, y(1) = 0

Homework Equations



The Attempt at a Solution



To solve, I divide everything by x dx to put everything in terms of v.

e^v + v = dy/dx

dy/dx = x dv/dx + v

e^v + v = x dv/dx + v

e^v = x dv/dx

e^v / dv = x/dx

Flip both sides.

e^-v dv = 1/x dx

Integrate both sides

-e^-v = ln|x| + c

-e^(-y/x) = e^(ln|x| + c)

-e^(-y/x) = x * e^c

-e^(-y/x) = cx

ln(-e^(-y/x)) = ln(cx)

ln(e^(x/-y)) = ln(cx)

-x/y = ln(cx)

1/y = -ln(cx)/x

y = -x/(ln(cx))

Is that the correct explicit form? Would it make it easier if I used the initial condition to find c, and then attempted to put it in explicit form, or not?
 
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-e^-v = ln|x| + c

-e^(-y/x) = e^(ln|x| + c)

this step does not follow. otherwise I think you're on the right track.
 

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