A. x2+y2=a

B. x2+y2=b

C. x2+y2=ab

D. x2+y2=a2+b2

If (1, a), (b, 2) are conjugate points with respect to the circle x^{2}+y^{2}=25, then 4a+2b=

The equation of the circle cutting orthogonally circles x^{2}+y^{2}-4x+3y-1=0 and passing through the points (-2, 5), (0, 0) is

If the points (k, 1), (2, -3) are conjugate w.r.t x^{2}+y^{2}+4x-6y-12=0 then k=

The equation to the locus of the midpoint of the chords of the circle x^{2}+y^{2}=r^{2} having a constant length 2l is

Consider the circles x^{2}+(y-1)^{2}=9, (x-1)^{2}+y^{2}=25. They are such that