Цитата(Тролль @ 18.3.2009, 15:55) 
y/x = t(x) => y = x * t(x) => y' = t(x) + x * t'(x)
Получаем, что
t + x * t' = t * ln t
x * dt/dx = t * ln t - t
dt/(t * ln t - t) = dx/x
int dt/(t * ln t - t) = int dx/x
int d(ln t)/(ln t - 1) = ln |x| + C
ln |ln t - 1| = ln |x| + C
ln t - 1 = C * x
ln t = 1 + C * x
t = e^(1 + C * x)
y = x * e^(1 + C * x)