“微信扫一扫”进入题库练习及模拟考试
已知圆
求圆
参考答案:设圆的方程为\({x^2} + {y^2} + Dx + Ey + F = 0\).\(\therefore \begin{cases}
2D + 5E + F = - 29 \\
5D + 2E + F = - 29 \\
2D - E + F = - 5 \\
\end{cases}\),解得\(\begin{cases}
D = - 4 \\
E = - 4 \\
F = - 1 \\
\end{cases}\),\(\therefore {x^2} + y{}^2 - 4x - 4y - 1 = 0\)即\({\left( {x - 2} \right)^2} + {\left( {y - 2} \right)^2} = 9\).
解析: