\((x, y, z)\) \((r, \theta ,z)\) \((\rho, \theta, \phi)\)
\((1,\,\_\kern-.5pt\_,\,\_\kern-.5pt\_)\) \(\left( \_\kern-.5pt\_,\,\_\kern-.5pt\_,\dfrac{-2\sqrt{3}}{3}\right)\) \(\left(\_\kern-.5pt\_,\dfrac{\pi}{6},\,\_\kern-.5pt\_\right)\)