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Questions in category: 解析几何 (Cartesian geometry).

通过所经过的九个点, 判断二次曲面属于哪一类曲面

Posted by haifeng on 2015-08-23 23:33:15 last update 2015-08-23 23:33:15 | Answers (1) | 收藏


已知二次曲面 $\Sigma$ (非退化)过以下九点:

\[
\begin{aligned}
A(1,0,0),\quad B(1,1,2),\quad C(1,-1,-2),\\
D(3,0,0),\quad E(3,1,2),\quad F(3,-2,-4),\\
G(0,1,4),\quad H(3,-1,-2),\quad I(5,2\sqrt{2},8).
\end{aligned}
\]

问 $\Sigma$ 是哪一类曲面?