Question

In the xy-plane, an equation of circle A is

x^2+(y-1)^2=1. Circle B is obtained by shifting
circle A one unit down. Which of the following is an
equation of circle B?
A) x^2+y^2=1
B) x² + (y-2)² = 1
C) (x - 1)^2 +(y – 1)^2 = 1
D) (x + 1)^2 + (y – 1)^2 = 1


Please with explanation

Answer 1

Answer: A

Explanation:

Because the center of circle A is (0,1) and circle B is one unit down, it would be x^2+y^2=1 because the center of circle B is (0,0). (The equation for a circle is (x-h)^2+(y-k)^2=r^2 with h and k as coordinates of the center of the circle and r as the radius.)