Question

The equation of the circle whose center is at (2, 1) and radius is 3 is

A. (x + 2)² + (y + 1)² = 9
B.(x - 2)² + (y - 1)² = 9
C.(x - 2)² + (y - 1)² = 3

Answer 1

The answer is B. (x - 2)^2 + (y - 1)^2 = 9 I got this question right on my assignment.

Answer 2

B. (x - 2)^2 + (y - 1)^2 = 9.

Explanation:

The general equation for a circle can be written as:

(x - a)^2 + (y - b)^2 = r^2 where the centre is at (a, b) and the radius= r.

Here a = 2, b = 1 and r = 3 so the answer is:

(x - 2)^2 + (y - 1)^2 = 3^2

= (x - 2)^2 + (y - 1)^2 = 9.