Find the distance between the following pairs of points

Find the distance between the following pairs of points

Find the distance between the following pairs of points:
(a) P1 (1, 2, 3) and P2 (- 2, – 3, -2) in Cartesian coordinates,
(b) P3 (1, ????????and P4 (3, ????????in cylindrical coordinates,
(c) P5 (4, ??2, 0) and P6 (3, ??????in spherical coordinates.