Posted by Beth on Friday, June 12, 2009 at 4:41pm.
State the center and the radius of the circle represented by the equation
(x + 1)^2 + (y – 5)^2 = 64

Algebra  Reiny, Friday, June 12, 2009 at 4:50pm
in the general equation of a circle
(xh)^2 + (yk)^2 = r^2
the centre is (h,k) and the radius is r
can you match this with your given equation? 
Algebra  Beth, Friday, June 12, 2009 at 5:22pm
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
(xh)^2 + (yk)^2 = r^2 making the center (1,5)? 
Algebra  Reiny, Friday, June 12, 2009 at 5:27pm
radius is correct,
the centre is (1,5) 
Algebra  Beth, Friday, June 12, 2009 at 5:29pm
That is what I thought, so the standard form would be
(x(1]^2 + (y5)^2 = 64 
Algebra  Reiny, Friday, June 12, 2009 at 5:34pm
yes,
I just mentally change the sign I see in the bracket 
Algebra  Beth, Friday, June 12, 2009 at 5:37pm
Great! Thanks for the help! So R= 8 and the center is (1,5) got it! Thanks again!