Question

The center of a circle is at (-5, 7) and its radius is 6 units. Which of the following is the equation for this circle?

A) (x - 5)2 + (y + 7)2 = 36
B) (x + 5)2 + (y - 7)2 = 36
C) (x - 5)2 + (y + 7)2 = 12
D) (x + 5)2 + (y - 7)2 = 12

Answer 1

Answer:
Option B, (x + 5)² + (y - 7)² = 36

Step-by-step explanation:

The equation for a circle is (x - h)² + (y - k)² = r² where r represents the radius of the circle and the center is ordered pair (h, k).

We can then plug the given information into the formula and simplify where possible.

Center at (-5, 7), radius = 6:
[x - (-5)]² + (y - 7)² = (6)²

(x + 5) + (y - 7)² = 36, which matches option B.