解答题 (共 12 题 ),解答过程应写出必要的文字说明、证明过程或演算步骤
设 $\boldsymbol{A}$ 为三阶矩阵, $|\boldsymbol{A}|=\frac{1}{2}$, 求 $\left|(2 \boldsymbol{A})^{-1}-5 \boldsymbol{A}^*\right|$.
设 $\boldsymbol{A}=\left(\begin{array}{rrr}0 & 3 & 3 \\ 1 & 1 & 0 \\ -1 & 2 & 3\end{array}\right), A B=A+2 B$, 求 $\boldsymbol{B}$.
设 $\boldsymbol{A}=\left(\begin{array}{lll}1 & 0 & 1 \\ 0 & 2 & 0 \\ 1 & 0 & 1\end{array}\right)$, 且 $\boldsymbol{A} \boldsymbol{B}+\boldsymbol{E}=\boldsymbol{A}^2+\boldsymbol{B}$, 求 $\boldsymbol{B}$.
设 $\boldsymbol{A}=\operatorname{diag}(1,-2,1), \boldsymbol{A}^* \boldsymbol{B} \boldsymbol{A}=2 \boldsymbol{B} \boldsymbol{A}-8 \boldsymbol{E}$, 求 $\boldsymbol{B}$.
已知 $\boldsymbol{A}$ 的伴随阵 $\boldsymbol{A}^*=\operatorname{diag}(1,1,1,8)$, 且 $\boldsymbol{A} \boldsymbol{B} \boldsymbol{A}^{-1}=\boldsymbol{B} \boldsymbol{A}^{-1}+3 \boldsymbol{E}$, 求 $\boldsymbol{B}$.
设 $\boldsymbol{P}^{-1} \boldsymbol{A} \boldsymbol{P}=\boldsymbol{\Lambda}$, 其中 $\boldsymbol{P}=\left(\begin{array}{rr}-1 & -4 \\ 1 & 1\end{array}\right), \boldsymbol{\Lambda}=\left(\begin{array}{rr}-1 & 0 \\ 0 & 2\end{array}\right)$, 求 $\boldsymbol{A}^{11}$.
设 $\boldsymbol{A} \boldsymbol{P}=\boldsymbol{P} \boldsymbol{\Lambda}$, 其中 $\boldsymbol{P}=\left(\begin{array}{rrr}1 & 1 & 1 \\ 1 & 0 & -2 \\ 1 & -1 & 1\end{array}\right), \boldsymbol{\Lambda}=\left(\begin{array}{lll}-1 & & \\ & 1 & \\ & & 5\end{array}\right)$,求 $\varphi(\boldsymbol{A})=\boldsymbol{A}^8\left(5 \boldsymbol{E}-6 \boldsymbol{A}+\boldsymbol{A}^2\right)$.
设矩阵 $\boldsymbol{A}$ 可逆, 证明其伴随阵 $\boldsymbol{A}^*$ 也可逆, 且 $\left(\boldsymbol{A}^*\right)^{-1}=\left(\boldsymbol{A}^{-1}\right)^*$.
设 $n$ 阶矩阵 $\boldsymbol{A}$ 的伴随阵为 $\boldsymbol{A}^*$, 证明:
(1)若 $|\boldsymbol{A}|=0$ ,则 $\left|\boldsymbol{A}^*\right|=0$ ;
(2)$\left|\boldsymbol{A}^*\right|=|\boldsymbol{A}|^{n-1}$.
计算 $\left(\begin{array}{llll}1 & 2 & 1 & 0 \\ 0 & 1 & 0 & 1 \\ 0 & 0 & 2 & 1 \\ 0 & 0 & 0 & 3\end{array}\right)\left(\begin{array}{rrrr}1 & 0 & 3 & 1 \\ 0 & 1 & 2 & -1 \\ 0 & 0 & -2 & 3 \\ 0 & 0 & 0 & -3\end{array}\right)$ 。
设 $\boldsymbol{A}=\left(\begin{array}{rrrr}3 & 4 & 0 & 0 \\ 4 & -3 & 0 & 0 \\ 0 & 0 & 2 & 0 \\ 0 & 0 & 2 & 2\end{array}\right)$, 求 $\left|\boldsymbol{A}^8\right|$ 及 $\boldsymbol{A}^4$.
求逆矩阵
$$
\left(\begin{array}{llll}
5 & 2 & 0 & 0 \\
2 & 1 & 0 & 0 \\
0 & 0 & 8 & 3 \\
0 & 0 & 5 & 2
\end{array}\right)
$$