4. Find the equation of the set of points which are equidistant from the points (1, 2, 3) and (3, 2, –1).
Given, two points A=(1, 2, 3) and B=(3, 2, –1).
Let the point P= (x,y,z) be a point which is equidistance from the points A and B.
so,
The distance PA= The distance PB
Now lets apply the simplification property,
Hence locus of the point which is equidistant from A and B is .