在等差数列{an}中，设公差为d，若前n项和为Sn＝－n2，则通项和公差分别为(　　)_刷题宝

题干

在等差数列{a_n}中，设公差为d，若前n项和为S_n＝－n²，则通项和公差分别为(　　)

A：a_n＝2n－1，d＝－2

B：a_n＝－2n＋1，d＝－2

C：a_n＝2n－1，d＝2

D：a_n＝－2n＋1，d＝2

上一题下一题 0.0难度选择题更新时间:2018-10-02 11:01:21

答案(点此获取答案解析）

B

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