One of the advantages of the hotel is that ________.
A. it is located in a business cneter
B. there are many restaurants nearb
C. its meeting space is the largest in the city
D. a laptop computer is available in each room
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设A是正交矩阵,则下列结论错误的是( ).
A. |A|2必为1
B. |A|必为1
C. A-1=AT
D. A的行(列)向量组是正交单位向量组
正交的两个向量的夹角是90度. ( )
A. 对
B. 错
含有零向量的向量组一定是正交向量组. ( )
A. 对
B. 错