Two tangents to the circle x² + y² = 4 at the points A and B meet at M($$-$$4, 0). The area of the quadrilateral MAOB, where O is the origin is

The locus of the centre of the circles which touch both the circles x² + y² = a² and x² + y² = 4ax externally is

The equation of circle of radius $$\sqrt {17} $$ unit, with centre on the positive side of X-axis and through the point (0, 1) is

A variable circle passes through the fixed point A(p, q) and touches X-axis. The locus of the other end of the diameter through A is