Question

Circle S has an equation of (x – 16)2 + (y – 9)2 = 4. What is the center and radius of circle S?
Answer
Center: (16, 9); Radius: 4
Center: (-16, -9); Radius: 4
Center: (16, 9); Radius: 2
Center: (-16, -9); Radius: 2

Answer 1

the third one.

Answer 2

madsci is right

Answer 3

can you explain? i really dont get it

Answer 4

circle equation:

(x-h)^2+(y-k)^2=r^2

h is the x coordinate, for the center, and k is the y coordinate for the center.
r is for radius.

Since (x-16)^2+(y-9)^2=4

we can say that r^2=4

so in order to find r we find the positive square root of four... which is two...
so r=2

we know that:
-16=-h
multiply both sides by negative 1

and you get 16=h
do the same for
-9=-k

and you get k=9

therefor, the coordinates for the center are (16,9) and the radius is 2

Answer 5

oh ok i understand thanks so much

Answer 6

no prob :)