Answer:
16. (x + 5)² + (y - 6)² = 1
17. (x - 6)² + (y + 9)² = 16
18. (x + 9)² + (y - 3)² = 121
Explanation:
Circle:
(x - h)² + (y - k)² = r²
16. Ends of a diameter: (-5, 5) and (-5, 7)
(h,k) = (-5-5)/2, (5+7)/2 = (-5,6)
Diameter = 7 - 5 = 2
Radius = 2/2 = 1
(x - (-5))² + (y - 6)² = 1²
(x + 5)² + (y - 6)² = 1
17. Ends of a diameter: (2, -9) and (10, -9)
(h,k) = (2+10)/2,(-9-9)/2 = (6,-9)
Diameter = 10 - 2 = 8
Radius = 8/2 = 4
(x - 6)² + (y - (-9))² = 4²
(x - 6)² + (y + 9)² = 16
18. Ends of a diameter: (-9, 14) and (-9, -8)
(h,k) = (-9-9)/2, (14-8)/2 = (-9,3)
Diameter = 14 - (-8) = 22
Radius = 22/2 = 11
(x - (-9))² + (y - 3)² = 11²
(x + 9)² + (y - 3)² = 121