ux=2ye^2xycos(y^2-x^2)+e^2xysin(y^2-x^2) *(-2x)=2ye^2xycos(y^2-x^2)-2xe^2xysin(y^2-x^2) uy=2xe^2xycos(y^2-x^2)+e^2xysin(y^2-x^2) *(2y)=2xe^2xycos(y^2-x^2)+2ye^2xysin(y^2-x^2)