A. (a, b)
B. (b, a)
C. (0, 0)
D. none
The equation of the circle cutting the circle x2+y2+2x-4y+8=0 orthogonally and coaxial with the circle x2+y2+6x-4y-12=0, x2+y2-4x-6y-12=0 is
The inverse point of (1, -1) with resapect to the circle x2+y2=4 is
The equation of the tangent to the circle x2+y2+2x+2y-7=0 which makes 450 with the x axis is
If OA, OB are two equal chords of the circle x2+y2-2x+4y=0 perpendicular to each other and passing through the origin, then the equations of OA and OB are
If the line 2x+3y+1=0 and 3x-y-4=0 lie along diameters of a circle of circumference 10π, then the equation of the circle is
The intercept made by the circle x2+y2-2hx sin θ-2ky sinθ=h2 cos2θ on the x-axis is
The system of circle x2+y2+2λx-5=0 is
The equation of the tangent to the circle x2+y2-2x-4y+3=0 at (2, 3) is
The equation of the circle with centre (3, -2) and radius 3 is
The circles x2+y2-10x+16=0 and x2+y2=r2 intersect each other into distinct points if