Squeezed Toward One

Problem

A sequence {an}\{a_n\} has an>0a_n > 0 and

an+1+1an<2for all nN.a_{n+1} + \frac{1}{a_n} < 2 \qquad \text{for all } n \in \mathbb{N}^*.

1. Prove that an+2<an+1<2a_{n+2} < a_{n+1} < 2. 2. Prove that an>1a_n > 1 for all nn.

Answer

Solution

Difficulty8/10
TopicsMonotonicity, Recursion, sequences, inequality

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