Цитата(Grom @ 19.3.2009, 16:45) *

(x^2-y^2)*y'=2xy/:x^2
(1-y^2/x^2)*dy/dx=2*x/y
Пусть y/x=t=>y=xt ; y'=t+x*t'
(1-t^2)(t-x*dt/dx)=2t


t = y/x => t' * x + t = 2t/(1 - t^2)