From 4f70171fc76b0b1792a0433f1d8250e157a24dcc Mon Sep 17 00:00:00 2001 From: idealist999 <2974730459@qq.com> Date: Wed, 31 Dec 2025 19:49:32 +0800 Subject: [PATCH] vault backup: 2025-12-31 19:49:32 --- ...231线性代数考试卷(解析版).md | 38 +++++++++++++++++-- 1 file changed, 35 insertions(+), 3 deletions(-) diff --git a/编写小组/试卷/1231线性代数考试卷(解析版).md b/编写小组/试卷/1231线性代数考试卷(解析版).md index e875ebf..2c4fd4a 100644 --- a/编写小组/试卷/1231线性代数考试卷(解析版).md +++ b/编写小组/试卷/1231线性代数考试卷(解析版).md @@ -194,10 +194,42 @@ $$A \to \begin{bmatrix} 1 & 1 & 3 & 1 & 0 & 1 \\ 0 & 1 & 1 & -1 & 1 & 2 \\ 0 & 2 \underline{\qquad\qquad\qquad\qquad}. $$ --- -解析: -一眼顶针,鉴定为: $$ - x = (1,0,0,0)^T$$ +**答**:$(1,0,0,0)^T$。 + +**解析**:由范德蒙行列式的性质可知 $|A| \neq 0$,从而线性方程组 $Ax = b$ 有唯一解。 + +又由 +$$ +\begin{bmatrix} +1 & a_1 & a_1^2 & a_1^3 \\ +1 & a_2 & a_2^2 & a_2^3 \\ +1 & a_3 & a_3^2 & a_3^3 \\ +1 & a_4 & a_4^2 & a_4^3 +\end{bmatrix} +\begin{bmatrix} +1 \\ +0 \\ +0 \\ +0 +\end{bmatrix} += +\begin{bmatrix} +1 \\ +1 \\ +1 \\ +1 +\end{bmatrix} +$$ +可知 $Ax = b$ 的解为 +$$ +\begin{bmatrix} +1 \\ +0 \\ +0 \\ +0 +\end{bmatrix} +$$ ---