(1/4)lgx(n+1)=1+lgxn 即:lgXn+1=lg10Xn即:Xn+1=10Xn,所以数列{Xn}为等比数列,公比为10 x1+
问题描述:
(1/4)lgx(n+1)=1+lgxn 即:lgXn+1=lg10Xn即:Xn+1=10Xn,所以数列{Xn}为等比数列,公比为10 x1+
答
lgx(n+1)=1+lgxn 即
答
lgxn+1=1+lgxn
lgxn+1=1+lgxn xn+1=10×xn即 =10
x1+x2+……+x100=100
x1+x1q+x1q2+……+x1q99=100
lg(x101+……+x200)
=lg(x1q100+……+x1q199)
=lg[q100(x1+……+x1q99)]
=102