A. x2/a2+y2/b2=1/a2

B. x2/a2+y2/b2=1/b2

C. x2/a4+y2/b4=1/a2

D. x2/a4+y2/b4=1/b2

If the line lx+my=1 is a normal to the ellipse x^{2}/a^{2}+y^{2}/b^{2}=1 then a^{2}/l^{2}-b^{2}/m^{2}=1

The radius of the circle passing through the foci of the ellipse x^{2}/16+y^{2}/9=1 and having its center at (0, 3) is

If x and y are strictly positive such that x+y =1,then the minimum value of x log x + y log y is

The locus of middle point of the chord of the ellipse x^{2}/a^{2}+y^{2}/b^{2}=1 touching the ellipse The locus of midpoint of the chord of the ellipse x^{2}/α^{2}+y^{2}/β^{2}=1

The points on the ellipse x^{2}/25+y^{2}/9=1 whose angles differ by a right angle are