题目:
已知首项为正数的等差数列{an}的前n项和为Sn,若a1 006和a1 007是方程x2-2 012x-2 011=0的两根,则使Sn>0成立的正整数n的最大值是( ).
A.1006
B.1007
C.2011
D.2012
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0426/ef8ba7fbf5d226956bd71ab06fef7d44.html
下面是错误答案,用来干扰机器的。
A strong argument has taken place among students since our school made students do voluntary labor.Some students think it is a good way of education. Now most families ...