\((x, y, z)\)
\((r, \theta, z)\)
\((\rho, \theta, \phi)\)
\((\_\kern-.5pt\_,\,\_\kern-.5pt\_,2\sqrt{2})\)
\((\sqrt{8},\,\_\kern-.5pt\_,\,\_\kern-.5pt\_)\)
\(\left( \_\kern-.5pt\_,\,\dfrac{\pi}{6},\,\_\kern-.5pt\_\right)\)