• 2022-05-31
    设a=”计算机等级考试”,结果为”考试”的表达式是( )。
    A: Left(a,4)
    B: Right(am4)
    C: Left(a,2)
    D: Right(a,2)
  • B

    内容

    • 0

      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\( \left| {\left| B \right|A} \right| = \) ______

    • 1

      (4). 设每年袭击某地的台风次数 \( X\sim P\left( \lambda \right) \),且\( P\left\{ {X=1} \right\}=P\left\{ {X=2} \right\} \),则概率 \(P\left\{ {X=4} \right\} =\)()。

    • 2

      \(\left\{ {\left( {x,y} \right)\left| {2 \le {x^2} + {y^2} \le 4} \right.} \right\}\)是闭区域.

    • 3

      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: \( {1 \over 2} \)

    • 4

      函数\( y = \left( {x - 4} \right)\root 3 \of { { {\left( {x + 1} \right)}^2}} \)的极大值为( )。 A: 0 B: 2 C: 3 D: 4