• $\frac{\mathit{x}}{\sqrt{{\mathit{x}}^2+{\mathit{y}}^2}}$
  
• $\frac{\mathrm{y}}{\sqrt{{\mathit{x}}^2+{\mathrm{y}}^2}}$
  
• $\frac{\mathit{x}}{\sqrt{{\mathit{x}}^2-{\mathit{y}}^2}}$
  
• $\frac{\mathrm{y}}{\sqrt{{\mathit{x}}^2-{\mathrm{y}}^2}}$