设`\A`为三阶矩阵,且`\A + E,A + 2E,A - 3E`均为奇异矩阵,则`\| A^** + 4E| = ` ( )
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设`\A,B,C`均为`\n`阶矩阵,已知`\det (E - A) \ne 0`.若`\B = E + AB,C = A + CA`,则`\B - C = ` ( )
A. `\-E`
B. `\O`
C. `\2E`
D. `\E`
设\[A = \left[ {\begin{array}{*{20}{c}} a&b\\ c&d \end{array}} \right]\]为正交阵,则`\ac + bd =` ( )
A. 1
B. -1
C. 0
D. 2
设`\A`是3阶方阵,且`\|A|=1`,`\A^**`是`\A`的伴随阵,则 ( )
A. \[{\left( {{A^*}} \right)^*} = {A^{ - 1}}\]
B. \[{\left( {{A^*}} \right)^*} = {A^*}\]
C. \[{\left( {{A^*}} \right)^*} = A\]
D. \[{\left( {{A^*}} \right)^*} = {A^T}\]
设`\A,B`为4阶方阵,且秩`\R(A) = 4,R(B) = 3`,`\A,B`的伴随阵为`\A^**,B^**`,则`\R(A^**B^**)` ( )
A. 1
B. 2
C. 3
D. 4