A. (x2/a2+y2/b2)2=d2 (x2/a4+y2/b4)

B. (x2/a2+y2/b2)2= (x2/a4+y2/b4)

C. (x2/a2+y2/b2)2=2d2 (x2/a4+y2/b4)

D. (x2/a2+y2/b2)2=d2 (x2/a4-y2/b4)

The locus of midpoint of the chord of the ellipse x^{2}/a^{2}+y^{2}/b^{2}=1 which pass through the fixed point (h, k) is

The equation of the auxiliary circle of x^{2}/12+y^{2}/18=1 is

If the chord of contact of the point (1, -2) with respect to the ellipse 4x^{2}+5y^{2}=20 is ax+by+c=0 then the ascending order of a, b, c is

The locus of a point P for which the chord of contact of x^{2}/a^{2}+y^{2}/b^{2}=1 touch the circle x^{2}+y^{2}=r^{2}

The value of k if (1, 2) (k, -1) are conjugate points with respect to the ellipse 2x^{2}+3y^{2}=6 is