# Some tip you can share to solve this equation?

1. Jan 12, 2015

### GodsmacK

Hi everyone,
I've been trying to solve the following equation:

$x^2(yy''-{y'}^2)+xyy'-y\sqrt{y^2+x^2y'^2}=0$

One of the tries was to do the substitution $z=xy'$. However, it doesnt seem to work...

Last edited: Jan 12, 2015
2. Jan 12, 2015

### Staff: Mentor

Try starting by dividing the equation by y2, and working with z =y'/y. This will reduce it to a first order equation in z.

Chet