Question

What is the equation of the circle if the radius is 9 and the center is (2, -7)?

1) (x + 2)+ (y – 7)? = 9
2) (x - 2)2 + (y + 7) = 9
3) (x + 2)2 + (y – 7)? = 81
4) (x - 2)2 + (y + 7)2 = 81

Answer 1

The equation of the circle with center (2, -7) and radius 9 is (x - 2)^2 + (y + 7)^2 = 81.

Step-by-step explanation:

The equation of a circle with center (h, k) and radius r is (x - h)^2 + (y - k)^2 = r^2.

In this case, the center is (2, -7) and the radius is 9. Plugging these values into the equation, we get (x - 2)^2 + (y + 7)^2 = 81.

Therefore, option 4) (x - 2)^2 + (y + 7)^2 = 81 is the correct equation of the circle.