Richirude
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Hello :)
I'm trying to solve an homogeneous equation... but it seems that I'm wrong in some step... or something, because I can't complete this problem, look here is what i got:
Solve the given homogeneous equation:
x\frac{dy}{dx} = ye^\frac{x}{y} - x
2. The attempt at a solution
x dy = (ye^\frac{x}{y} - x) dx
x dy + ( -ye^\frac{x}{y} + x) dx
Using substitution
x = vy
dx = vdy + ydv
vy dy + (-ye^v + vy) [ vdy + ydv ] = 0
(vy + yv^2 - vye^v)dy + (vy^2 - y^2e^v )dv = 0
(vy + yv^2 - vye^v)dy = (y^2e^v - vy^2 )dv
\frac{(y)(v + v^2 - ve^v)}{y^2(e^v - v)} dy = dv
\int \frac{1}{y} dy = \int \frac{(e^v - v)}{(v + v^2 - ve^v)} dv
The integral on the left side is easy to solve, but I can't find a way to solve the right side of the equation. Maybe I'm wrong in some earlier step...
Any Suggestions?
Thanks and sorry for my English, I'm still learning it (i'm from venezuela)
I'm trying to solve an homogeneous equation... but it seems that I'm wrong in some step... or something, because I can't complete this problem, look here is what i got:
Homework Statement
Solve the given homogeneous equation:
x\frac{dy}{dx} = ye^\frac{x}{y} - x
2. The attempt at a solution
x dy = (ye^\frac{x}{y} - x) dx
x dy + ( -ye^\frac{x}{y} + x) dx
Using substitution
x = vy
dx = vdy + ydv
vy dy + (-ye^v + vy) [ vdy + ydv ] = 0
(vy + yv^2 - vye^v)dy + (vy^2 - y^2e^v )dv = 0
(vy + yv^2 - vye^v)dy = (y^2e^v - vy^2 )dv
\frac{(y)(v + v^2 - ve^v)}{y^2(e^v - v)} dy = dv
\int \frac{1}{y} dy = \int \frac{(e^v - v)}{(v + v^2 - ve^v)} dv
The integral on the left side is easy to solve, but I can't find a way to solve the right side of the equation. Maybe I'm wrong in some earlier step...
Any Suggestions?
Thanks and sorry for my English, I'm still learning it (i'm from venezuela)