Tentukan pusat dan jari jari x^2+y^2-8x-2y-8=0x

x^2 + y^2 -8x -2y -8 = 0
(x - 4)^2 -4^2 +(y -1)^2 -1^2 -8 = 0
(x - 4)^2 + (y -1)^2 -16 -1-8 = 0
(x - 4)^2 +(y -1)^2-25;= 0
(x -4)^2 +(y -1)^2 = 25
Pusat ( 4, 1 ) dan r = √25 = 5