The sum of the reciprocals of focal distances of a focal chord `PO` of `y^2=4ax` is

The sum of the reciprocals of focal distances of a focal chord PQ of y^(2) =4ax is

Show that the sum of the reciprocals of the segments of any focal chord of a parabola y^2=4ax is constant.

Prove that the sum of the reciprocals of the segments of any focal chord of a parabola is constant .

The Harmonic mean of the segments of a focal chord of the parabola y^(22)=4ax is

Show that the product of the ordinates of the ends of a focal chord of the parabola y^(2) = 4ax is constant .

The locus of the centre of the circle described on any focal chord of the parabola y^(2)=4ax as the diameter is