A. a2x2-b2y2=c4

B. a2x2+b2y2=c4

C. a2x2+b2y2=c2

D. b2x2+a2y2=c4

The tangents are drawn to the ellipse x^{2}/a^{2}+y^{2}/b^{2}=1 at point where it is intersected by the line lx+my+n=0. The point of intersection of tangents at these points is

If the lines 4x+3y-1=0,x-y+5=0 and kx+5y-3=0 are concurrent,then k is equal to

The product of the slopes of the tangents to the ellipse 2x^{2}+3y^{2}=6 draw from the point (1, 2) is

The ordinate PN of P(a cos θ, b sin θ) on the ellipse x^{2}/a^{2}+y^{2}/b^{2}=1 meets the auxiliary circle at Q,. The locus of the point of intersection of normal at P and Q is

The locus of the middle point of chords of the ellipse x^{2}/a^{2}+y^{2}/b^{2}=1 whose pole lies on the auxiliary circle is