Question

What is the center and radius of the circle with the equation (x + 10)2 + (y + 15)2 = 121 ?

Answer 1

Hint:

(x + 10)^2 + (y + 15)^2 = 121

(x - (-10))^2 + (y - (-15))^2 = 121

(x - (-10))^2 + (y - (-15))^2 = 11^2


Compare the last equation to (x-h)^2+(y-k)^2=r^2

Answer 2

\[(x-h)^2+(y-k)^2 = a^2\]
e\where (h,k) is the the centre and r is the radius

Answer 3

Keep in mind that

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

has a center of (h,k) and a radius of r

Answer 4

so the radius is 121 i'm guessing...and the center must be 10.-15?

Answer 5

10,-15

Answer 6

the radius is NOT 121

Answer 7

r^2 = 121

r = ???

Answer 8

11 ^w^!

Answer 9

yep

Answer 10

(h,k) = ???

Answer 11

10,15?

Answer 12

close, but your signs are off

Answer 13

-10,-15

Answer 14

if

x - h = x + 10

then h must be -10

Answer 15

yep, center is (-10, -15)

Answer 16

yes! ^w^ thanks dude!

Answer 17

np