题目(1)设随机变量X的分布律为-|||-X -2 0 2-|||-pk 0.4 0.3 0.3-|||-求E(X),E(X ^2), (3(X)^2+5) 。-|||-(2)设 sim pi (lambda ) ,求 (dfrac (1)(X+1)) 题目解答答案