The points are , and .

Find which point is closest to the -plane.

The -plane is the plane that contains the - and -axes.

The -plane is the plane that contains the - and -axes.

The -plane is the plane that contains the - and -axes.

The distance formula for three dimension is .

In - plane , and .

.

The distance from - plane is from any point.

For , .

For , .

For , .

The smallest distance from - plane is .

The point is the closest to the - plane.

Which point lies in the - plane.

The -plane is the plane that contains the - and -axes and - axis is zero.

Observe the points:

In point , the - axis is zero.

Therefore, the pont lies in the - plane.

lies in the - plane.

The point is the closest to the - plane.

lies in the - plane.