A. 4

B. -9

C. -3

D. -5

Equation of the circle touching the y-axis at (0, √3) and cuts the x-axis in the points (- 1, 0) and (-3, 0) is

The equation of the common tangent at the point contact of the circles x^{2}+y^{2}-10x+2y+10=0, x^{2}+y^{2}-4x-6y+12=0 is

The number of tangents that can be drawn from (6, 0) to the circle x^{2}+y^{2}-4x-6y-12=0 are

The locus of the middle points of portions of the tangents to the circle x^{2}+y^{2}=a^{2} terminated by the axes is

If the length of the tangets from two points A, B to a circles are 6, 7 respectively. If A, B are conjugate points then AB=