Question

State the center and the radius of the circle represented by the equation

(x + 1)^2 + (y – 5)^2 = 64

Answer 1

in the general equation of a circle
(x-h)^2 + (y-k)^2 = r^2
the centre is (h,k) and the radius is r

can you match this with your given equation?

Answer 2

ok based on that I would say the radius is 8 cause 8*8 = 64 and the center is (1,5)? Or do the signs change because of the equation
(x-h)^2 + (y-k)^2 = r^2 making the center (-1,5)?

Answer 3

radius is correct,
the centre is (-1,5)

Answer 4

That is what I thought, so the standard form would be

(x-(-1]^2 + (y-5)^2 = 64

Answer 5

yes,
I just mentally change the sign I see in the bracket

Answer 6

Great! Thanks for the help! So R= 8 and the center is (-1,5) got it! Thanks again!