A circle `S` of radius `' a '` is the director circle of another circle `S_1,S_1` is the director circle of circle `S_2` and so on. If the sum of the radii of all these circle is 2, then the value of `' a '` is `2+sqrt(2)` (b) `2-1/(sqrt(2))` `2-sqrt(2)` (d) `2+1/(sqrt(2))`

A circle x^(2)+y^(2)+4x-2sqrt(2)y+c=0 is the director circle of circle S_(1) and S_(2) ,is the director circle of circle S_(1), and so on.If the sum of radii of all these circles is 2, then find the value of c.

A circle x^(2)+y^(2)+4x-2sqrt(2)y+c=0 is the director circle of the circle S_(1) and S_(1) is the director circle of circle S_(2), and so on.If the sum of radii of all these circles is 2 ,then the value of c is k sqrt(2), where the value of k is

The radius of the circle passing through the points (1, 2), (5, 2) and (5, -2) is : (A) 5sqrt(2) (B) 2sqrt(5) (C) 3sqrt(2) (D) 2sqrt(2)

If C_1: x^2+y^2=(3+2sqrt(2))^2 is a circle and P A and P B are a pair of tangents on C_1, where P is any point on the director circle of C_1, then the radius of the smallest circle which touches c_1 externally and also the two tangents P A and P B is 2sqrt(3)-3 (b) 2sqrt(2)-1 2sqrt(2)-1 (d) 1

The equation of director circle to the circle x^(2) + y^(2) = 8 is

Find the equation of the circle with : Centre (-a, -b) and radius sqrt(a^2 - b^2) .

Three circles of radius 1 cm are circumscribed by a circle of radius r, as shown in the figure. Find the value of r? (a) sqrt(3) + 1 (b) (2+sqrt(3))/(sqrt(3)) (c) (sqrt(3) + 2)/(sqrt(2)) (d) 2 + sqrt(3)

If m(x-2)+sqrt(1-m^(2))y=3, is tangent to a circle for all m in[-1,1] then the radius of the circle is

Find the equation of the circle with : Centre (1, 1) and radius sqrt(2) .