关于a1a3a4的百科

• 已知公差不为0的等差数列{an}满足a1,a3,a4成等比数列,Sn为数列{an}的前n项和,则的值为(　　)...

• 问题详情：已知公差不为0的等差数列{an}满足a1,a3,a4成等比数列,Sn为数列{an}的前n项和,则的值为()A.-2                        B.-3                   C.2                    D.3【回答】.C解析设等差...
• 2021-05-239674