Coordinate Planes

The three coordinate axes determine the three coordinate planes.

The xy-plane is the plane that contains the x- and y-axes;

the yz-plane is the plane that contains the y- and z-axes;

the xz-plane is the plane that contains the x- and z-axes.

Point Coordinates as Distances from Coordinate Planes

If P(x, y, z) is a point in space, then

x is the directed distance from the yz-plane to the point P,

y is the directed distance from the xz-plane to the point P, and

z is the directed distance from the xy-plane to the point P.

For the point P(3, 2, 6), determine the directed distance from each coordinate plane.

a. 6
b. 2
c. 3

1. The directed distance from P(3, 2, 6) to the xy-axis.
2. The directed distance from P(3, 2, 6) to the yz-axis.
3. The directed distance from P(3, 2, 6) to the xz-axis.