Question

On a coordinate plane, a circle has a center at (1, negative 2) and a radius of 4 units.
Which equation represents a circle with the same radius as the circle shown but with a center at (-1, 1)?

(x – 1)2 + (y + 1)2 = 16
(x – 1)2 + (y + 1)2 = 4
(x + 1)2 + (y –1)2 = 4
(x + 1)2 + (y – 1)2 = 16

Answer 1

Center (-1, 1) and radius 4 give (x - (-1))^2 + (y - 1)^2 = 4^2, so

(x + 1)^2 + (y - 1)^2 = 16.

Thus the correct choice is: (x + 1)^2 + (y - 1)^2 = 16.