Question

помогите пожалуйста!!

Answer 1

yy'' + (y')² - (y')³lny = 0

y' = p(y), y'' = p'y' = p'p

ypp' + p² - p³lny = 0

yp' + p = p²lny

u(y) = py, u' =p'y + p, p = u/y

u' = u² lny / y²

u'/u² = lny/y²

-1/u = C - (1+lny)/y

y/p = -C + (1+lny)/y, p = y'

y'(1 - Cy + lny)/y² = 1

-1/y - Clny - (1+lny)/y = x - A

x = A - (2 + lny + Cylny)/y