具有n个顶点的完全图,其边的总数为 __-|||-(A) dfrac (n!)(2) (B) dfrac (n(n-1))(2)-|||-(C) dfrac (
+dfrac (sin n)({2)^n} ;-|||-(2) _(n)=1+dfrac (1)({2)^2}+dfrac (1)({3)^2}+... +df
+dfrac (n)({n)^2+n+n})=dfrac (1)(2)证明:
lim _(narrow infty )(dfrac (1)({n)^2+n+1}+dfrac (2)({n)^2+n+2}+... +dfrac (n)({n
_(n)=((-1))^n+1dfrac (1)(sqrt {n)}-|||-C. _(n)=sin dfrac (npi )(2)-|||-D. _(n)=d
+(n)^3);-|||-(2) lim _(narrow infty )n[ dfrac (1)({(n+1))^2}+dfrac (1)({(n+2))^2
-1 0 -1 0 0 的值为 ()-|||-A 1-|||-B ((-1))^dfrac (n(n-1){2)}-|||-C -1-|||-D ((-1))
+dfrac (1)(n(n+1)) =-|||-(3) lim _(narrow infty )(dfrac (1)(2)+dfrac (3)({2)^2}+
(D) dfrac ((n-1){S)^2}({sigma )^2}sim (chi )^2(n)
lim _(narrow infty )(dfrac (1)({n)^2+(e)^-1+1}+dfrac (2)({n)^2+(e)^-2+2}+dfrac (