20.[单选题] 设 =cos i ,则 ()-|||-A (A) lim _(narrow infty )(m)_(n)=0-|||-~z=0;-|||-B (B) =pi :;-|||-C (C) |z|=0 =-|||-D (D) argz=π

已知 lim _(narrow infty )(a)_(n)=2 lim _(narrow infty )(b)_(n)=3已知 lim _(narrow in

11.(单选题) 设C为正向圆周|z|=2，则oint_(c)(bar(z))/(z^2)dz=（ ） A (A.)-2πi; B (B.) 0;

极限lim _(narrow +infty )((dfrac {1)(3))}^n= A 0 B 1极限A0B1

设 ^2=sum _(n=0)^infty (a)_(n)cos nx,(-pi leqslant xleqslant pi ), 则 _(3)= __ 艹

下列极限中正确的是lim _(narrow infty )(7)^dfrac (1{x)}=0-|||-→0lim _(narrow infty )(7)^df

→(a)→∞-|||-lim _(narrow infty )(x)_(n)=+infty lim _(narrow infty )(y)_(n)=infty

1.单选题-|||-设 sim N(M,(sigma )^2) ,则 +b 服从-|||-A N(0,1)-|||-B ○ (aM+b,(a)^2(a)^2)-

__-|||-lim _(narrow infty )([ sin (dfrac {pi )(4)+dfrac (1)(n))] }^n=( )A.

根据数列极限定义证明：(1) lim _(narrow infty )dfrac (1)({n)^2}=0-|||-(2) lim _(narrow infty

设 (x)=sin x g(x)= -pi ,xleqslant 0-|||-+pi ,xgt 0-|||-则 [ g(x)] =() .-|||-A、sinx