Respostas

2014-02-04T16:49:07-02:00
x² + y² -4x + 4y = 0
x² - 4x + 4 + y² + 4y + 4= 4 + 4
(x - 1)² + (y + 2)² = 8
C = (+1,-2)
r = √8 = 2√2