du/dx=df'(ux)/dx*(ux)'+df'(v+y)/dx*(v+y)'=df'(ux)/dx*(u'+u)+df'(v+y)/dx*v'dv/dx=dg'(u-x)/dx*(u-x)'+dg'(v^2y)/dx*(v^2y)'=dg'(u-x)/dx*(u'-1)+dg'(v^2y)/dx*(2vy)
