Find the equation of the circle whose centre is (1,1) and radius 3.

Find the equation of the circle whose centre is (-3, 2) and radius 4.

Find the equation of the circle whose centre is (2, -1) and which passes through (3, 6).

Find the equation of a sphere whose centre is (3, 1, 2) and radius is 5.

In each of the following find the equation of the circle with centre (1/2, 1/4) and radius 1/12 .

In the following ,find the equation of the circle with:- centre (1/2,1/4) and radius 1/12

Find the equation of the circle with the centre (1/2,1/4) and radius 1/2 .

Find the equation of the circle whose centre is (2, -3) and which passes through the intersection of the straight lines 3x-2y=1 and 4x+y = 27.

Find the equation of the circle whose centre is (h, k) and which touches : x-axis.

Find the equation of the circle whose centre is (h, k) and which touches : y-axis.

Find the equation of the circle whose centre is (h, k) and which touches : both axes.