（xy-y^2)dx-(x^2-2xy)dy=0微分方程通解
问题描述：
（xy-y^2)dx-(x^2-2xy)dy=0微分方程通解
答
令u=y/x,怎样推到dy/dx=u+x*du/dx 令u=y/x,y = x * u,y ' = u + x * u ' 即 dy/dx = u + x * du/dx
（xy-y^2)dx-(x^2-2xy)dy=0微分方程通解
令u=y/x,怎样推到dy/dx=u+x*du/dx 令u=y/x,y = x * u,y ' = u + x * u ' 即 dy/dx = u + x * du/dx