ims2n+1=lm(52n+2+)=s n→0 n→0 级数收敛于和s,且s≤u1 余项rn=±(un1-un2+…)2 LL,+ 2 满足收敛的两个条件,≤ n+1 定理证毕lim lim( ) 2 1 2 2 +1 → + →  = n + n n n n s s u = s, , . u1 级数收敛于和s 且s  ( ), 余项rn =  un+1 − un+2 + , rn = un+1 − un+2 + 满足收敛的两个条件, .  n  un+1 r 定理证毕