Answer:
(x + 1)² + (y - 9)² = 4²
Explanation:
equation of circle is (x - a)² + (y - b)² = r²
where a is x-coordinate of centre of circle, b is y-coordinate of centre of circle, r is the radius. radius = half of diameter.
(x - -1)² + (y - 9)² = 4²
(x + 1)² + (y - 9)² = 4²