Answer:
The general point on xy plane is D(x, y, 0).
Consider this point is equidistant to the points A(2, 0, 3), B(0, 3, 2) and C(0, 0, 1).
∴ AD = BD
Squaring on both sides,
(x – 2)2+ (y – 0)2 + (0 – 3)2 = (x – 0)2 + (y – 3)2 + (0 – 2)2
x2 – 4x +4 + y2 + 9 = x2 + y2 -6y + 9 + 4
-4x = -6y ….(1)
AD = CD
Squaring on both sides,
(x – 2)2+ (y – 0)2 + (0 – 3)2 = (x – 0)2 + (y – 0)2 + (0 – 1)2
x2 – 4x +4 + y2 + 9 = x2 + y2 +1
-4x = -12 ….(2)
Solving equation (1) and (2),
x = 3, y = 2.
The point which is equidistant to the points A(2, 0, 3), B(0, 3, 2) and C(0, 0, 1) is (3, 2, 0).