设A、B、C是任意三个随机事件，则下列命题正确的是( )(Acup B)-B=A-B(Acup B)-B=A-B(Acup B)-B=A-B(Acup B)-B=A-B

设2 -2 -4 2 -3 -5-|||-A= -1 3 4 B= -1 4 5-|||-1 -2 -3 1 -3 -4（1）验证2 -2 -4 2 -3 -5-|||-A= -1 3 4 B= -1 4 5-|||-1 -2 -3 1 -3 -4;（2）利用（1）证明2 -2 -4 2 -3 -5-|||-A= -1 3 4 B= -1 4 5-|||-1 -2 -3 1 -3 -4（一般地，若2 -2 -4 2 -3 -5-|||-A= -1 3 4 B= -1 4 5-|||-1 -2 -3 1 -3 -4，称方阵2 -2 -4 2 -3 -5-|||-A= -1 3 4 B= -1 4 5-|||-1 -2 -3 1 -3 -4为幂等矩阵）.

4.iintlimits_(D)xydsigma 其中区域D是由抛物线y=x^2-1及直线y=1-x所围成的区域；

计算：(1)/(3)×(3)/(5)+1(5)/(7)-(5)/(9)×(5)/(7)1-(5)/(7)×(21)/(25)(1)/(2)+(5)/(4)×(4)/(5)(1)/(6)×（5-(2)/(3)）(7)/(8)×7+(3)/(8)．

4.计算下列各行列式:-|||-4 1 2 4-|||-1 2 0 2-|||-(1)-|||-10 5 2 0-|||-0 1 1 7-|||--ab ac ae-|||-(3) bd -cd de-|||-bf cí -ef-|||-2 1-|||-3 -12 1-|||-(2) ;-|||-1 2-|||-5 0 6 2-|||-1 1 1-|||-(4) a b c-|||-b+c c+a a+b-|||-a 1 0 0-|||--1 b 1 0-|||-(5)-|||-0 -1 c 1-|||-0 0 -1 d-|||-1 2 3 4-|||-1 3 4 1-|||-(6)-|||-1 4 1 2-|||-1 1 2 3

设本题涉及的事件均有意义.设A,B都是事件.-|||-(1)已知 (A)gt 0, 证明 (AB|A)geqslant P(AB|Acup B).-|||-(2)若 (A|B)=1, 证明 (overline (B)|overline (A))=1.-|||-(3)若设C也是事件,且有 (A|C)geqslant P(B|C) (A|overline (C))geqslant P(B|overline (C)), 证明-|||-(A)geqslant P(B).

9.设 D= 3 1 -1 2 -5 1 3 -4 2 0 1 -1 1 -5 3 -3 D的(i,j)元的代数余子式记作A9,求-|||-_(31)+3(A)_(32)-2(A)_(33)+2(A)_(34)

[单选题](z)=(z)^2+dfrac (1)({z)^2-1}f'(z)=( )A. (z)=(z)^2+dfrac (1)({z)^2-1}f'(z)=( )B. (z)=(z)^2+dfrac (1)({z)^2-1}f'(z)=( )C. (z)=(z)^2+dfrac (1)({z)^2-1}f'(z)=( )D. (z)=(z)^2+dfrac (1)({z)^2-1}f'(z)=( )

1.3分别用图解法和单纯形法求解下述线性规划问题,并对照指出单纯形表中的各基-|||-可行解分别对应图解法中可行域的哪一顶点.-|||-(a) =10(x)_(1)+5(x)_(2)-|||-s. t-|||- ) 3(x)_(1)+4(x)_(2)leqslant 9 5(x)_(1)+2(x)_(2)leqslant 8 (x)_(1),(x)_(2)geqslant 0 .

一、对于任意的事件A.B,C,已知 P(A)=0.6 P(B)=0.4 , (C)=0.2; 则-|||-(1)若 (Aoverline (B))=0.3, 求P(A∪B)-|||-(2)若 (Acup B)=0.8, 求P(AB)-|||-(3)若 =. (AB)=P(BC)=0.1, 求P(A∪B∪C)

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