Find the equation of the circle which passes through (1, 0) and (0, 1) and has its radius as small as possible.

Find the equation of a sphere which passes through (1,0,0)(0,1,0)a n d(0,0,1), and has radius as small as possible.

Find the equation of a sphere which passes through (1,0,0)(0,1,0)a n d(0,0,1), and has radius as small as possible.

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

Find the equation of the circle with centre at (-1,0) and radius 2.

Find the equation (s) of the circle passing through the points (1,1) and (2,2) and whose radius 1 .

Find the equation of the circle with centre (0,2) and radius 2

Find the equation of the circle with centre (1,1) and radius sqrt(2)

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

Find the equation of the lines passing through the point (1,1) and (-2,3)