设等比数列{an}的前n项和为sn.己知a2=6,6a1+a3=30,求an和Sn要详细过程...
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发布时间:2024-10-02 17:52
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热心网友
时间:2024-10-19 04:29
a2^2 = a1*a3 = 36
6a1 + a3 = 30
a1 = 2,a3 = 18或者a1 =3 ,a3 =12
等比q = 3或者2
Sn = 3^n - 1 或者 3(2^n - 1)
热心网友
时间:2024-10-19 04:36
a2^2 = a1*a3 = 36
6a1 + a3 = 30
a1 = 2,a3 = 18或者a1 =3 ,a3 =12
等比q = 3或者2
Sn = 3^n - 1 或者 3(2^n - 1)