A. x2+y2=a2

B. x2+y2=r2

C. x2+y2=r2+a2

D. x2+y2=r2-a2

The The limiting points of the coaxal system x^{2}+y^{2}+2µy+9=0 are

If (2, 1 )is limiting point of the coaxal system of which x^{2}+y^{2}-6x-4y-3=0 is a member, then the other limiting point is

The locus of the point of intersection of two perpendicular tangents to the circle x^{2}+y^{2}=a^{2}, x^{2}+y^{2}=b^{2} is

The equation of the image of the circle x^{2}+y^{2}-6x-4y+12=0 by the line mirror x+y-1=0 is

The inverse point of (1, 2) w.r.t the circle x^{2}+y^{2}=25 is (5, k), then k=