设 \( A \)为 \( m \times n \)矩阵， \( B \)为 \( n \times m \)矩阵，则下列结论中不正确的是（ ）
A: \( {\left( {AB} \right)^T} = {B^T}{A^T} \)
B: \( \left| {AB} \right| = \left| {BA} \right| \)
C: \( tr\left( {AB} \right) = tr\left( {BA} \right) \)
D: \( {A^T}A,\;B{B^T} \)均为\(n\)阶对称阵
A: \( {\left( {AB} \right)^T} = {B^T}{A^T} \)
B: \( \left| {AB} \right| = \left| {BA} \right| \)
C: \( tr\left( {AB} \right) = tr\left( {BA} \right) \)
D: \( {A^T}A,\;B{B^T} \)均为\(n\)阶对称阵
B
举一反三
- 设`\A`是`\m \times n`矩阵，`\m` 小于 `\n`，则必有 （ ） A: \[\left| {{A^T}A} \right| \ne 0\] B: \[\left| {{A^T}A} \right| = 0\] C: \[\left| {A{A^T}} \right| > 0\] D: \[\left| {A{A^T}} \right| < 0\]
- 设\( A,\;B \) 均为\( n \) 阶方阵，则必有（ ）. A: \( {(A + B)^2} = {A^2} + 2AB + {B^2} \) B: \( \left| {A + B} \right| = \left| A \right| + \left| B \right| \) C: \( \left| {AB} \right| = \left| A \right|{\kern 1pt} \left| B \right| \) D: \( {\left( {AB} \right)^{\rm T}} = {A^{\rm T}}{B^{\rm T}} \)
- 设\( A,B \)均为\( n \)阶方阵，则必有（ ） A: \( \left| {A + B} \right| = \left| A \right| + \left| B \right| \) B: \( AB = BA \) C: \( \left| {AB} \right| = \left| {BA} \right| \) D: \( {\left( {A + B} \right)^{ - 1}} = {A^{ - 1}} + {B^{ - 1}} \)
- 设\(A\)为\(n\)阶方阵,\(\left| A \right| = 2 \)，则\(\left| {\left| A \right|{A^T}} \right|=\) A: \({2^{n + 1}} \) B: \({2^{n }}\) C: \({2^{n - 1}}\) D: \(2\)
- 设 \( A \)是 \( 3 \times 3 \)矩阵， \( B \)是 \( 4 \times 4 \)矩阵，且\( \left| A \right| = 1,\,\left| B \right| = - 2, \) 则\( \left| {\left| B \right|A} \right| = \) ______
内容
- 0
设向量组\( {\left( {2,1,1,1} \right)^T},{\left( {2,1,a,a} \right)^T},{\left( {3,2,1,a} \right)^T},{\left( {4,3,2,1} \right)^T} \) 线性相关，且\( a \ne 1 \) ，则 \( a = \)______
- 1
设 \( A \)为方阵，则 \( \left| { { A^T}} \right| = \,\left| A \right|\, \).（ ）
- 2
设\( A,B \) 为方阵，则 \( \left| {AB} \right| = \,\left| A \right|\,\left| B \right| \)。（ ）
- 3
设\( A \) ，\( B \)为\( n \)阶方阵，满足关系 \( AB = O \)，则必有（ ） A: \( A = B = O \) B: \( A + B = O \) C: \( \left| A \right| = 0 \)或\( \left| B \right| = 0 \) D: \( \left| A \right| + \left| B \right| = 0 \)
- 4
设\(n\)阶矩阵\(A\)的伴随矩阵为\({A^ * }\),若\(\left| A \right| = 0\)，则\(\left| { { A^ * }} \right| \ne 0\).