A. a=2c a) a=2c b) |a|=2c c) 2|a|=c d) |a|=c

B. |a|=2c

C. 2|a|=c

D. |a|=c

The area of the quadrilateral formed by the tangents from the point (4,5) to the circle x^{2}+y^{2}-4x-2y-11=0 with a pair of radii joining the points of contact of these tangents is

The equation of the normal to the curve (x/a)^{2/3}+(y/b)^{2/3}=1 at (a cos^{3}θ, b sin^{3}θ ) is

The distance between the limiting points of the coaxial system x^{2} + y^{2} – 4x – 2y – 4 + 2λ(3x + 4y + 10)=0

The condition that the pair of tangents drawn from the origin to the circle x^{2}+y^{2}+2gx+2fy+c=0 may be at right angles is

The equation of the chord of the circle x^{2}+y^{2}+16x+2y+10=0 parallel to the chord x-3y-15=0 and which is at the same distance from the centre is