明天要交了 还有两道不是很会做.1 ,等比数列{An}中,A1+An=66,A2A(n-1)=128 ,求项数n2,已知项数{An}的前n项和的公式为Sn=32n-n² ,求数列{│An│}的前n项和Tn.
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/30 17:20:53
![明天要交了 还有两道不是很会做.1 ,等比数列{An}中,A1+An=66,A2A(n-1)=128 ,求项数n2,已知项数{An}的前n项和的公式为Sn=32n-n² ,求数列{│An│}的前n项和Tn.](/uploads/image/z/1741270-22-0.jpg?t=%E6%98%8E%E5%A4%A9%E8%A6%81%E4%BA%A4%E4%BA%86+%E8%BF%98%E6%9C%89%E4%B8%A4%E9%81%93%E4%B8%8D%E6%98%AF%E5%BE%88%E4%BC%9A%E5%81%9A.1+%2C%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97%7BAn%7D%E4%B8%AD%2CA1%2BAn%3D66%2CA2A%EF%BC%88n-1%EF%BC%89%3D128+%2C%E6%B1%82%E9%A1%B9%E6%95%B0n2%2C%E5%B7%B2%E7%9F%A5%E9%A1%B9%E6%95%B0%7BAn%7D%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8C%E7%9A%84%E5%85%AC%E5%BC%8F%E4%B8%BASn%3D32n-n%26sup2%3B+%2C%E6%B1%82%E6%95%B0%E5%88%97%7B%E2%94%82An%E2%94%82%7D%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8CTn.)
xRN@~Tm%XF=UgIPIHR 1]`g
O.*^V3}3}KNJj߃sk̝*ZNfr҄syUT5"{6oyie=T&5t]2,*]6T4"lk) =_;G1 {]
Ʃ*GI\^&&v*h>//5=(;IATܘ@idmN