Answer:
It is C) (x − 1)^2 + (y + 3)^2 = 4
Explanation:
The radius is the distance between the center and the point on the circle.
Center: (1, −3); Point: (1, −1)
Distance formula: d = square root of {(x2 - x1)^2 + (y2 - y1)^2}
r = square root of {(1 − 1)^2 + (−1 + 3)^2 }
r = square root of {0 + 4 } = 2
(x − h)^2 + (y − k)^2 = r2 ----> (x − 1)^2 + (y + 3)^2 = 4
Hope this isn't confusing and helps. I also know its right because I just did this on USA Testprep.