Найти y'x и y''xx : 3x+sin y =5y
1) 3 + cos(y)*y' - 5*y' = 0; 3 = y'(5 - cos(y)); y' = 3/(5 - cos(y)); 2)y'' = -(3*(sin(y)*y')/(5-cos(y))^2 = (-9*sin(y))/(5 - cos(y))^3