Field and Wave Electromagnetics 2nd Edition by David Cheng

Exercise 45

Prove that the equation of any plane in space can be written in the form b 1 x + b 2 y + b 3 z = c. (Hint: Prove that the dot product of the position vector to any point in the plane and a normal vector is a constant.)
b) Find the expression for the unit normal passing through the origin.
c) For the plane 3 x - 2 y + 6 z = 5, find the perpendicular distance from the origin to the plane.