设圆的方程是x^2 + y^2 + Dx + Ey + F = 0,分别代入三点
{ 1 + E + F = 0
{ 1 - E + F = 0
{ 16 + 4D + F = 0
解得：D = - 15/4,E = 0,F = - 1
所以一般式方程是x^2 + y^2 - (15/4)x - 1 = 0
化为标准式方程是(x - 15/8)^2 + y^2 = 289/64