单选题 (共 4 题 ),每题只有一个选项正确
下列行列式中等于零的是
$\text{A.}$ $\left|\begin{array}{ccc}1 & 2 & 3 \\ -1 & 0 & 3 \\ 2 & 2 & 5\end{array}\right|$
$\text{B.}$ $\left|\begin{array}{ccc}1 & 2 & 3 \\ -1 & 0 & 2 \\ 2 & 2 & 3\end{array}\right|$
$\text{C.}$ $\left|\begin{array}{ccc}1 & 2 & 3 \\ 0 & -4 & 0 \\ -2 & -7 & -6\end{array}\right|$
$\text{D.}$ $\left|\begin{array}{ccc}2 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & -2 & 3\end{array}\right|$
设 $\alpha _1, \alpha _2, \alpha _3, \beta _1, \beta _2$ 都是 4 维列向量,且 4 阶行列式 $\left| \alpha _1, \alpha _2, \alpha _3, \beta _1\right|=m,\left| \alpha _1, \alpha _2, \beta _2, \alpha _3\right|=n$ ,则 4 阶行列式 $\left| \alpha _3, \alpha _2, \alpha _1, \beta _1+ \beta _2\right|$ 等于
$\text{A.}$ $m+n$
$\text{B.}$ $-(m+n)$
$\text{C.}$ $n-m$
$\text{D.}$ $m-n$
设 $D=\left|\begin{array}{lll}a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33}\end{array}\right|, A_{i j}$ 为 $D$ 的 $(i, j)$ 元的代数余子式,则 $A_{31}+2 A_{32}+3 A_{33}=$
$\text{A.}$ $\left|\begin{array}{ccc}a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ 1 & 2 & 3\end{array}\right|$
$\text{B.}$ $\left|\begin{array}{ccc}a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ 1 & -2 & 3\end{array}\right|$
$\text{C.}$ $\left|\begin{array}{lll}a_{11} & a_{12} & 1 \\ a_{21} & a_{22} & 2 \\ a_{31} & a_{32} & 3\end{array}\right|$
$\text{D.}$ $\left|\begin{array}{llc}a_{11} & a_{12} & 1 \\ a_{21} & a_{22} & -2 \\ a_{31} & a_{32} & 3\end{array}\right|$
已知 $| A |=\left|\begin{array}{cccc}a_1 & a_2 & a_3 & a_4 \\ 2 & 2 & 1 & 1 \\ 2 & 3 & 4 & 5 \\ 1 & 1 & 2 & 2\end{array}\right|=9$ ,则代数余子式 $A_{21}+A_{22}=$
$\text{A.}$ 3
$\text{B.}$ 6
$\text{C.}$ 9
$\text{D.}$ 12
填空题 (共 3 题 ),请把答案直接填写在答题纸上
计算$\left|\begin{array}{llll}
a & b & c & d \\
x & 0 & 0 & y \\
y & 0 & 0 & x \\
d & c & b & a
\end{array}\right|=$
$\left|\begin{array}{cccc}
1 & b_1 & 0 & 0 \\
-1 & 1-b_1 & b_2 & 0 \\
0 & -1 & 1-b_2 & b_3 \\
0 & 0 & -1 & 1-b_3
\end{array}\right|=$
已知 4 阶行列式 $\left| \alpha _1, \alpha _2, \alpha _3, \beta \right|=a,\left| \beta + \gamma , \alpha _2, \alpha _3, \alpha _1\right|=b$ ,其中 $\alpha _1, \alpha _2, \alpha _3, \beta , \gamma$ 均为 4 维列向量,计算 $\left| \alpha _1, \alpha _3, \alpha _2, \gamma \right|$ .
解答题 (共 3 题 ),解答过程应写出必要的文字说明、证明过程或演算步骤
计算$\left|\begin{array}{cccc}
-1 & -1 & -1 & -1 \\
-1 & -1 & -1 & 1 \\
-1 & -1 & 1 & 1 \\
-1 & 1 & 1 & 1
\end{array}\right|$
$\left|\begin{array}{cccc}
-a_1 & 0 & 0 & 1 \\
a_1 & -a_2 & 0 & 1 \\
0 & a_2 & -a_3 & 1 \\
0 & 0 & a_3 & 1
\end{array}\right|$
已知方程 $\left|\begin{array}{ccc}x-2 & 0 & 0 \\ -3 & x-1 & a \\ 2 & a & x-1\end{array}\right|=0$ 有二重根,求满足条件的常数 $a$ 及方程的根