- #1
Ed Aboud
- 201
- 0
Homework Statement
Solve
[tex] y \frac{d^2y}{dt^2} + (\frac{dy}{dt})^2 = 1 [/tex]
Homework Equations
The Attempt at a Solution
[tex] \frac{dy}{dt} = v[/tex]
[tex] \frac{d^2y}{dt^2} = v \frac{dv}{dy}[/tex]
[tex] yv \frac{dv}{dy} + v^2 =1 [/tex]
[tex] \frac{dv}{dy} + \frac{v}{y} = \frac{1}{vy} [/tex]
[tex] I(y) = exp ( \int \frac{1}{y} dy)[/tex]
[tex] I(y) = y [/tex]
[tex] y \frac{dv}{dy} + v = \frac{1}{v}[/tex]
[tex] \frac{d}{dy} (vy) = \frac{1}{v}[/tex]
[tex] y= \frac{ln(v)}{v} + \frac{C}{v} [/tex]
Thanks.