Find the radius of the circle which passes through the origin and the points (a, 0) and (0, b).

Find the equation of a circle which passes through the origin and whose centre is (a, b).

Find the equation of a circle which passes through the origin and whose centre is (a, b).

Find the equation of the circle which passes through the points (1,1), (0, -1) and (-2, 0)

Find the equation of the circle which passes through the points (0,0), (0,1) and (2,3)

Find the slope of the line which passes through the origin and the mid-point of the line segment joining the points A (0, -4) and B (8, 0) .

Find the slope of the line which passes through the origin and the mid-point of the line segment joining the points A (0, -4) and B (8, 0) .

Find the equation of the straight line which passes through the origin and the point of intersection of the lines ax+by+c=0 and a'x+b'y+c'=0 .

Find the equation to the circles which pass through the points : (i) (0,0),(a,0) and (0,b)

Find the equation of the circle passing through the three points (0,0) ,(a,0) and (0,b).

The least radius of the circle which passes through the points (1,0)&(0,1) is