From the points on the circle x2 + y2 = a2, tangents are drawn to the hyperbola x2 – y2 = a2; then the locus of the middle points of the chords of contact is the curve
(x2 – y2)2 = a2(x2 – y2)
(x2 – y2)2 = 2a2(x2 + y2)
(x2 – y2)2 = a2(x2 + y2)
(x2 + y2)2 = a2(x2 + y2)
