If you observe carefully you will find that the given points are not collinear. We will start by considering the first three points. We know that there always exist a circle that pass through any three non collinear points. So the centre of ths circle is equidistant from the three points. Now we will prove that the fourth point also lies on this circle.
Let us represent the first three points parametrically as (am,a/m). Let the centre of this circle be (α,β). Let the radius of the circle be r. So
(am-α)2 + (a/m-β)2 = r2
So this is biquadratic equation. So it must have four roots. m1,m2,m3 are already roots of this eqn. Let the fourth root be m4.
If you expand the eqn you will find that the product of the roots is 1. ie m1m2m3m4 = 1
So we get m4 = 1/m1m2m3
ie the fouth point is (am4,a/m4) ie (a/m1m2m3,am1m2m3)
Please like the solution if you understand it.
RAJORSHI PAUL
1st year
Dept of Electrical Engineering
IIT Kharagpur