极限 lim_(n to infty) (1)/(n) sum_(i=1)^n sqrt(1 + (i)/(n)) 用定积分表示为(）A. $\int_{0}^
判别下列级数的绝对收敛性与收敛性：(1) sum_(n=1)^infty (i^n)/(n); (2) sum_(n=2)^infty (i^n)/(ln n
若 lim_(n to infty) u_n = 0，则级数 sum_(n=1)^infty u_n（）A. 一定收敛B. 一定发散C. 绝对收敛D. 可能收敛
2、设级数sum_(n=1)^inftya_(n)收敛，lim_(ntoinfty)na_(n)=a.证明：sum_(n=1)^inftyn(a_(n)-a_(
13.设 sum _(i=1)^infty (a)_(n)=1, 则 sum _(n=1)^infty ((a)_(n)-2(a)_(n+1))= __
若lim_(n to infty) b_n = +infty, 则级数sum_(n=1)^infty ((1)/(b_n) - (1)/(b_(n+1)) )的
根据数列极限的定义证明：(1) lim_(n to infty) (1)/(n^2) = 0;(2) lim_(n to infty) (3n+1)/(2n+1
5、设级数sum_(n=1)^infty(-1)^na_(n)2^n收敛，则级数sum_(n=1)^inftya_(n)（）.A. 条件收敛B. 绝对收敛C.
12 lim_(n to infty) (1+2+3+...+(n-1))/(n^2);12 $\lim_{n \to \infty} \frac{1+2+3+
1.6 总体X-N(mu,sigma^2)，x_(1),x_(2),...,x_(n)为其样本，bar(x)=(1)/(n)sum_(i=1)^nx_(i)，s