An equation of the plane that is parallel to the x,y-plane and that passes through (2,7,3)is
A) x = 2.
B) y = 7.
C) z = 3.
D) x = 7.
E) y = 3.

Question

Quizplus · Accepted Answer

Since the plane is parallel to the x,y-plane, its normal vector is perpendicular to the x,y-plane and has a direction parallel to the z-axis. Therefore, any point on the plane has a z-coordinate of 3. Thus, the equation of the plane is z=3.

An Equation of the Plane That Is Parallel to the X,y-Plane