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已知函数f(x)=1+2/x ,数列{xn}满足x1=11/7 Xn+1 =f(Xn),若bn=1/Xn -2 +1/3求证数列{bn}是等比数列,并求其通项公式若Cn=3^n - abn(a为非零整数,n属于N*) 试确定a的值,使得对任意n属于N*,都有Cn+1 >C...全文
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teacherzhy：bn=1/(xn-2)+1/3=(xn+1)/3(xn-2) b(n+1)=1/[x(n+1)-2]+1/3 =1/[f(xn)-2]+1/3 =1/[(1+2/xn)-2]+1/3 =2(xn+1)/3(2-xn) b(n+1)/bn=-2(定值） b1=1/(11...(2011-05-10 11:14)
