A. a, b, c

B. b, c, a

C. a, c, b

D. b, a, c

The two circles (x-a)^{2}+(y-b)^{2}=c and (y-b)^{2}+x^{2}=4c have only one real common tangent then

The locus of the point whose shortest distance from the circle x^{2}-2x+6y-6=0 is equal to its distance from the line x-3=0 is

A=(cosθ, sinθ) and B==(sinθ, -cosθ) are two points. The locus of the centroid of ΔOAB where O is the origin is

The conjugate system of the coaxal system x^{2}+y^{2}+2ax+2by+2λ(ax-by)=0, λ is a parameter, is

The locus of the midpoint of the chord of the circle x^{2}+y^{2}-2x-2y-2=0, which makes an angle of 120^{0} at the centre is