Question

Please help! A circle is centered at (−4, −6) and has a radius of 3. Which of the following is the equation for this circle?


(x + 4)2 + (y + 6)2 = 3

(x − 4)2 + (y − 6)2 = 9

(x − 4)2 + (y − 6)2 = 3

(x + 4)2 + (y + 6)2 = 9

Answer 1

General equation of a circle is

(x - a)^2 + (y - b)^2 = r^2 where (a, b) is the center and r = radius. so here we have a = -4 and b = -6 and r^2 = 3^2 = 9

Therefore the equation of the required circle is

(x + 4)^2 + (y + 6)^2 = 9