A. a2/|x1y1|
B. a2/|x1y1|
C. a4/|x1y1|
D. a2/2|x1y1|
The equations of the tangents drawn from the origin x2+y2+2gx+2fy+f2=0 is
The area of the triangle formed by the tangents from (1, 3) to the circle x2+y2-4x+6y+1=0 and its chord of contact is
The condition that the pair of tangents drawn from (g, f) to the circle x2+y2+2gx+2fy+c=0 may be at right angles is
The equation of the circle passing through the points of intersection of the circles x2+y2-8x+10y+2=0, x2+y2-3x+5y-1=0 and touching line 2x+y=3 is
The equation of the circle passing the origin having its centre on the line x+y=4 and cutting the circle x2+y2-4x+2y+4=0 orthogonally is
The limiting points of the coaxal system x2+y2+2λx+4=0 are
The equation of the circle passing through (2, 1) and touching the coordinate axes is
The length of the tangent from the point (-1, 1) to the circle x2+y2-4x+k=0 is equal to 2 then k=
The equations of the tangents to the circle x2+y2=16 which are inclined at an angle of 600 to the x-axis is
The common chord of x2+y2-4x-4y=0 and x2+y2=16 substends at the origin an angle equal to