Find the center and the radius of the circle.
-$$( x + 5 ) ^ { 2 } + ( y - 9 ) ^ { 2 } = 15$$
A) center $( - 5,9 )$; radius $= 15$
B) center $( 5 , - 9 )$; radius $= \sqrt { 15 }$
C) center $( - 5,9 )$; radius $= 225$
D) center $( - 5,9 )$; radius $= \sqrt { 15 }$

Question

Quizplus · Accepted Answer

The equation of a circle in the form $(x - h)^2 + (y - k)^2 = r^2$ has a center at $(h, k)$ and a radius of $r$. The given equation $(x + 5)^2 + (y - 9)^2 = 15$ matches this form with $h = -5$, $k = 9$, and $r^2 = 15$, meaning $r = \sqrt{15}$.

Find the Center and the Radius of the Circle (x+5)2+(y−9)2=15( x + 5 ) ^ { 2 } + ( y - 9 ) ^ { 2 } = 15(x+5)2+(y−9)2=15

Find the Center and the Radius of the Circle $( x + 5 ) ^ { 2 } + ( y - 9 ) ^ { 2 } = 15$