Question

Find the radius of the circle whose equation is (x - 2)2 + (y - 4)2 = 9.
O 81
09
3

Answer 1

r = 3

Explanation:

The stock equation for a circle of center (h, k) and radius r is

(x - h)^2 + (y - k)^2 = r^2. Comparing this with the given (x - 2)^2 + (y - 4)^2 = 9, we see that r^2 must be 9 and therefore r = 3.

Answer 2

3

Explanation:

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

The equation of a circle is written as

(x-h)^2+ (y-k)^2 = r^2

where ( h,k) is the center and r is the radius

(x - 2)^2 + (y - 4)^2 = 3^2

The center is ( 2,4) and the radius is 3