22.(15 分)已知数列 $\left\{x_{n}\right\}$ 满足:$x_{1}=1, x_{n}=x_{n+1}+\ln \left(1+x_{n+1}\right)\left(n \in N^{*}\right)$ ,证明:当 $n \in \mathrm{N}^{*}$ 时,
( I ) $0
(III)$\frac{1}{2^{n-1}} \leqslant x_{n} \leqslant \frac{1}{2^{n-2}}$ .
2017 高考数学第 22 题答案解析
2017_浙江卷 (2017)