`S` is a circle having the center at `(0,a)` and radius `b(b < a)dot` A variable circle centered at `(alpha,0)` and touching the circle `S` meets the X-axis at `Ma n dN` . Find the a point `P` on the Y-axis, such that `/_M P N` is a constant for any choice of `alpha`

The equation of the circle having centre at (3,7) and radius 5 units is _

The equation of the circle having centre at (3,7)and radius 5 units is

Find the equation of the circle with centre at (0,0) and radius r .

Find the equation of the circle having center at (2,3) and which touches x+y=1 .

Find the equation of the circle having center at (1,2) and which touches x+y=-1 .

Let C be the circle with centre at (1, 1) and radius = 1. If T is the circle centered at (0, Y) passing through origin and touching the circle C externally, then the radius of T is equal to :

The locus of the midpoint of a line segment that is drawn from a given external point P to a given circle with center O (where O is the orgin) and radius r is (a) straight line perpendiculat to P O (b) circle with center P and radius r (c) circle with center P and radius 2r (d) circle with center at the midpoint P O and radius r/2dot

A circle touches the x-axis and also touches the circle with centre (0,3) and radius2. The locus of the centre of the circle is

In one of the diameters of the circle, given by the equation x^(2) + y^(2) - 4x + 6y - 12 = 0 , is a chord of a circle S , whose center is at (-3 , 2) , then the radius of S is

C_1 and C_2 are circle of unit radius with centers at (0, 0) and (1, 0), respectively, C_3 is a circle of unit radius. It passes through the centers of the circles C_1a n dC_2 and has its center above the x-axis. Find the equation of the common tangent to C_1a n dC_3 which does not pass through C_2dot