Question

True or False?

If a point belongs to both the xy-plane and the xz-plane, then the point lies on the x-axis.

Answer

True.

If a point belongs to the xy-plane then its z-component equals `0`.

If a point belongs to the xz-plane then its y-component equals `0`.

Thus, point has form `(x_0,0,0)`. This means that it lies on the x-axis.