Bounds for non-linear recursive sequence

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SUMMARY

The discussion centers on the real sequence defined by the recurrence relation x_{n+1} = (x_n)^2 - 100 + sin(n). It is established that if the sequence is bounded by positive numbers, then it must satisfy the condition 10 <= x_n <= 11 for all n >= 0. The participants confirm that if any term x_n falls below 10 or exceeds 11, the sequence becomes unbounded or negative, thus reinforcing the bounded nature of the sequence within the specified limits.

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  • Understanding of recursive sequences and their properties
  • Familiarity with mathematical induction techniques
  • Knowledge of bounded sequences in real analysis
  • Basic trigonometric functions, specifically sine
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  • Learn about mathematical induction and its applications in proofs
  • Explore bounded sequences and their implications in calculus
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Homework Statement



We are given the real sequence x_n+1 = (x_n)^2 - 100 + sin(n), some x_0

Prove that if the sequence is bounded with positive numbers, then necessarily
10 <= x_n <= 11 for all n>=0.

Homework Equations





The Attempt at a Solution


I tried induction and it didn't work. Not sure what's the way to go. Thanks for the help!
 
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You could prove the following: if there exist an n such that xn<10 of xn>11, then the sequence becomes unbounded or negative. Try a few examples first!
 
Worked perfectly. Thanks a lot!
 

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