Consider the lines L₁ and L₂ defined by ${\mathrm{L}}_1:\mathrm{x}\sqrt{2}+\mathrm{y}-1=0$ and ${\mathrm{L}}_2:\mathrm{x}\sqrt{2}-\mathrm{y}+1=0$

For a fixed constant $\mathrm{\lambda }$, let C be the locus of a point P such that the product of the distance of P from L₁ and the distance of P from L₂ is ${\mathrm{\lambda }}^2$. The line y = 2x +1 meets C at two points R and S, where the distance between R and S is $\sqrt{360}$.

Let the perpendicular bisector of $RS$ meet $C$ at two distinct points R’ and S’. Let $D$ be the square of the distance between R’ and S’