• 2022-06-17
    设\( {\alpha _1} = {\left( {1,2, - a, - 3} \right)^T},{\alpha _2} = {\left( { - 3,2,4,1} \right)^T} \)且\( \left( { { \alpha _1},{\alpha _2}} \right) = - 1 \),则\( a = \)( )
    A: \( - {2 \over 3} \)
    B: \( - {3 \over 4} \)
    C: \( - {1 \over 4} \)
    D: \( {1 \over 2} \)
  • 举一反三