C is the centre of the circle with centre `(0,1)` and radius unity. `y=ax^2` is a parabola. The set of the values of `'a'` for which they meet at a point other than the origin, is

The locus of the centre of the circle described on any focal chord of the parabola y^(2)=4ax as the diameter is

Two circles with centres C_(1),C_(2) and same radius r cut each other orthogonally,then r is

Let C be the circle with centre at (1, 1) and radius = 1. If T is the circle centred at (0, y), passing through origin and touching the circle C externally, then the radius of T is equal to (1) (sqrt(3))/(sqrt(2)) (2) (sqrt(3))/2 (3) 1/2 (3) 1/4

Find the centre and radius of the circles : x^2 + y^2 - ax - by = 0

Find the radius and centre of the circle of the circle x^(2) + y^(2) + 2x + 4y -1=0 .

A square OABC is formed by line pairs xy=0 and xy+1=x+y where o is the origin .A circle with circle C_(1) inside the square is drawn to touch the line pair xy=0 and another circle with centre C_(2) and radius twice that C_(1) is drawn touch the circle C_(1) and the other line . The radius of the circle with centre C_(1)