• 2022-06-16
    ‎下面哪个矩阵肯定不是随机向量x的协差阵。‌
    A: [img=158x85]1803102fd6b6e31.png[/img]
    B: [img=133x71]1803102fe0f6ff3.png[/img]
    C: [img=85x51]1803102feb8c665.png[/img]
    D: [img=111x63]1803102ff59dda5.png[/img]