两边夹定理的典型例题 求lim[1/n^2+1/(n+1)^2+...+1/(2n)^2](n→∞）; 因为1/n^2+1/n^2+...+1/n^2（n个1/n^2）≤1/n^2+1/(n+1)^2+...+1/(2n)^2≤1/n(n+1)+1/(n+1...
