Find the center and the radius of the circle.
-$$( x + 4 ) ^ { 2 } + ( y - 9 ) ^ { 2 } = 81$$
A) $( - 4,9 ) , \mathrm { r } = 9$
B) $( 9 , - 4 ) , \mathrm { r } = 9$
C) $( 4 , - 9 ) , \mathrm { r } = 81$
D) $( - 9,4 ) , \mathrm { r } = 81$ Graph the equation and state its domain and range. Use interval notation

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 $r$. For the given equation, $(x + 4)^2 + (y - 9)^2 = 81$, the center is $(-4, 9)$ and the radius is $\sqrt{81} = 9$.

Find the Center and the Radius of the Circle (x+4)2+(y−9)2=81( x + 4 ) ^ { 2 } + ( y - 9 ) ^ { 2 } = 81(x+4)2+(y−9)2=81

Find the Center and the Radius of the Circle $( x + 4 ) ^ { 2 } + ( y - 9 ) ^ { 2 } = 81$