A. 5
B. 1
C. 2
D. 3
If 5x-12y+10=0 and 12y-5x+16=0 are two tangents to a circle,then the radius of the circle is
The tangents at (3, 4), (4, -3) to the circle x2+y2=25 are
The equation of the circle cutting orthogonally circles x2+y2+2x+8=0, x2+y2-8x+8=0 and which touches the line x-y+4=0 is
If the circle S=x2+y2-16=0 intersects another circle S’=0 of radius 5 in such a manner that the common chord is of maximum length and has a slope equal to 3/4 then the centre of S’=0 is
The locus of the midpoints of chords of the circle x2+y2=25 which touch the circle (x-2)2+(y-5)2=289 is
If (3,2 )is limiting point of the coaxal system of circles whose common radical axis is 4x+2y=11, then the other limiting point is
An equilateral triangle is inscribed in the circle x2+y2=a2 . The length of the side of the triangle is
The length of the intercept made by the circle x2+y2-12x+14y+11=0 on x-axis is
I: The equation of the circle concentric with x2+y2-2x+8y-23=0 and passing through (2, 3) is x2+y2-2x+8y-33=0
II: : The equation of the circle passing through the points (1, 1), (2, -1), (3, 2) is x2+y2-5x-y+4=0
If a circle passes through the point (a, b) and cuts the circle x2+y2=4 orthogonally, then the locus of its centre is