A point is in the XZ-plane. What can you say about its y-coordinate?

A point is on the x-axis. What are its y coordinate and z-coordinates?

Name the octants in which the following points lie:

(1, 2, 3), (4, –2, 3), (4, –2, –5), (4, 2, –5), (– 4, 2, –5), (– 4, 2, 5), (–3, –1, 6) (2, – 4, –7).

Fill in the blanks:

(i) The x-axis and y-axis taken together determine a plane known as _______.

(ii) The coordinates of points in the XY-plane are of the form _______.

(iii) Coordinate planes divide the space into ______ octants.

Find the distance between the following pairs of points:

(2, 3, 5) and (4, 3, 1)