x2+y2x\frac{\sqrt{x^{2}+y^{2}}}{x}xx2+y2
x2+y2y\frac{\sqrt{x^{2}+y^{2}}}{y}yx2+y2
yx2+y2\frac{y}{\sqrt{x^{2}+y^{2}}}x2+y2y
xx2+y2\frac{x}{\sqrt{x^{2}+y^{2}}}x2+y2x