(2)似然函数:L()=Ⅱ e i=1x! hmL(4)=-n+∑x1m-∑hn(x1!) d In L(n) -n+ d元 n元 ∑xλ λ Πλ − = = e !x )( )(L i x n i 1 2 似然函数： !x e n x i i λ Π λ =1 − = ∑∑ = = +−= − n i i n i i lnxn)(Lln )!xln( 1 1 λλ λ 0 1 1 ∑ =⋅+−= = n i i xn d )(Llnd λ λ λ ∑ = = n i i nx 1 λ .xx n n i ∑ i = = = 1 1 λ