Question

Give the equation for a circle with the given center and radius. Center at (2, -9), radius = 3

A. (x−9)2+(y+2)2=3
B. (x−2)2+(y+9)2=9
C. (x+2)2+(y−9)2=9
D. (x+9)2+(y−2)2=3

Answer 1

B

Explanation:

The standard form of the equation of a circle is

(x - h)² + (y - k)² = r²

where (h, k) are the coordinates of the centre and r is the radius

Here (h, k) = (2, - 9) and r = 3, thus

(x - 2)² + (y - (- 9))² = 3², that is

(x - 2)² + (y + 9)² = 9 → B