6. If A and B be the points (3, 4, 5) and (-1, 3, -7), respectively, find the equation of the set of points P such that , where k is a constant.
Given points,
A (3, 4, 5) and B (-1, 3, -7),
Let the coordinates of point P be (x,y,z)
Now,
Given condition :
And
Now, given Condition
Hence, equation of the set of points P is
.