Question #N333
In the $xy$-plane, a circle has a center at $(4, -3)$ and a radius of $5$ units. What is the equation of the circle?
A. (x - 4)^2 + (y + 3)^2 = 25
B. (x + 4)^2 + (y - 3)^2 = 25
C. (x - 4)^2 + (y + 3)^2 = 5
D. (x + 4)^2 + (y - 3)^2 = 5
Correct Answer is: A
The standard form of the equation of a circle with center $(h, k)$ and radius $r$ is $(x-h)^2 + (y-k)^2 = r^2$. Substituting the given values of $(h, k) = (4, -3)$ and $r=5$, we get the equation $(x - 4)^2 + (y + 3)^2 = 5^2$, or $(x - 4)^2 + (y + 3)^2 = 25$.