题目
填空题(共3题,30.0分)6.(10.0分)求解下列矩阵方程:(}1&0&00&0&10&1&0),则x_(11)=_____;x_(12)=_____;x_(13)=_____;x_(21)=_____;x_(22)=_____;x_(23)=_____;x_(31)=_____;x_(32)=_____;x_(33)=_____.
填空题(共3题,30.0分)
6.(10.0分)求解下列矩阵方程:
$\left(\begin{matrix}1&0&0\\0&0&1\\0&1&0\end{matrix}\right)\left(\begin{matrix}0&1&0\\1&0&0\\0&0&1\end{matrix}\right)\left(\begin{matrix}1&3&5\\2&4&-4\\-1&-2&0\end{matrix}\right)$,设$X=\left(\begin{matrix}x_{11}&x_{12}&x_{13}\\x_{21}&x_{22}&x_{23}\\x_{31}&x_{32}&x_{33}\end{matrix}\right)$,
则
$x_{11}=$_____;
$x_{12}=$_____;
$x_{13}=$_____;
$x_{21}=$_____;
$x_{22}=$_____;
$x_{23}=$_____;
$x_{31}=$_____;
$x_{32}=$_____;
$x_{33}=$_____.
题目解答
答案
设矩阵 $A = \begin{pmatrix}1&0&0\\0&0&1\\0&1&0\end{pmatrix}$,$B = \begin{pmatrix}0&1&0\\1&0&0\\0&0&1\end{pmatrix}$,$C = \begin{pmatrix}1&3&5\\2&4&-4\\-1&-2&0\end{pmatrix}$。
先计算 $AB$:
\[
AB = \begin{pmatrix}0&1&0\\0&0&1\\1&0&0\end{pmatrix}
\]
再计算 $(AB)C$:
\[
(AB)C = \begin{pmatrix}2&4&-4\\-1&-2&0\\1&3&5\end{pmatrix}
\]
因此,矩阵 $X$ 的元素为:
\[
\boxed{
\begin{array}{ccccccccc}
x_{11} &=& 2, & x_{12} &=& 4, & x_{13} &=& -4, \\
x_{21} &=& -1, & x_{22} &=& -2, & x_{23} &=& 0, \\
x_{31} &=& 1, & x_{32} &=& 3, & x_{33} &=& 5
\end{array}
}
\]