Use the given information about a circle to find its equation.
-Center $( - 5 , - 4 )$ and diameter 10
A) $( x - 5 ) ^ { 2 } + ( y - 4 ) ^ { 2 } = 25$
B) $( x + 5 ) ^ { 2 } + ( y + 4 ) ^ { 2 } = 100$
C) $( x + 5 ) ^ { 2 } + ( y + 4 ) ^ { 2 } = 25$
D) $( x - 5 ) ^ { 2 } + ( y - 4 ) ^ { 2 } = 100$

Question

Quizplus · Accepted Answer

The equation of a circle with center $(h, k)$ and radius $r$ is $(x - h)^2 + (y - k)^2 = r^2$. Given the center $(-5, -4)$ and diameter $10$, the radius is $10/2 = 5$. Thus, $r^2 = 25$, and the correct equation is $(x + 5)^2 + (y + 4)^2 = 25$.

Use the Given Information About a Circle to Find Its (−5,−4)( - 5 , - 4 )(−5,−4)

Use the Given Information About a Circle to Find Its $( - 5 , - 4 )$