已知数列an=4n-2和bn=2/4^(n-1),设Cn=an/bn,求数列{Cn}的前n项和Tn我晓得这道题的回答是解:Cn=an/bn=(4n-2)/[2/4^(n-1)]=(n-1)4^(n-1)Tn=0+1*4+2*4^2+3*4^3+.+(n-1)4^(n-1)4Tn=1*4^2+2*4^3+3*4^4……(n-1)4^nTn-4Tn=4+4^2+4^3+...+4^(n-1
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![已知数列an=4n-2和bn=2/4^(n-1),设Cn=an/bn,求数列{Cn}的前n项和Tn我晓得这道题的回答是解:Cn=an/bn=(4n-2)/[2/4^(n-1)]=(n-1)4^(n-1)Tn=0+1*4+2*4^2+3*4^3+.+(n-1)4^(n-1)4Tn=1*4^2+2*4^3+3*4^4……(n-1)4^nTn-4Tn=4+4^2+4^3+...+4^(n-1](/uploads/image/z/1389357-45-7.jpg?t=%E5%B7%B2%E7%9F%A5%E6%95%B0%E5%88%97an%3D4n-2%E5%92%8Cbn%3D2%2F4%5E%28n-1%29%2C%E8%AE%BECn%3Dan%2Fbn%2C%E6%B1%82%E6%95%B0%E5%88%97%7BCn%7D%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8CTn%E6%88%91%E6%99%93%E5%BE%97%E8%BF%99%E9%81%93%E9%A2%98%E7%9A%84%E5%9B%9E%E7%AD%94%E6%98%AF%E8%A7%A3%EF%BC%9ACn%3Dan%2Fbn%3D%EF%BC%884n-2%29%2F%5B2%2F4%5E%28n-1%29%5D%3D%28n-1%294%5E%28n-1%29Tn%3D0%2B1%2A4%2B2%2A4%5E2%2B3%2A4%5E3%2B.%2B%28n-1%294%5E%28n-1%294Tn%3D1%2A4%5E2%2B2%2A4%5E3%2B3%2A4%5E4%E2%80%A6%E2%80%A6%28n-1%294%5EnTn-4Tn%3D4%2B4%5E2%2B4%5E3%2B...%2B4%5E%28n-1)
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