Proving convergence of Sequence dependent on previous terms

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SUMMARY

The sequence defined by the recurrence relation xn+1 = (2009xn + 2010)/2011 converges for x1 > 9000. By applying the Monotone Convergence Theorem, it is established that the sequence is both monotone and bounded. To prove monotonicity, one must analyze the difference xn+1 - xn and determine the conditions under which this difference is negative, indicating a monotonically decreasing sequence. This analysis will also reveal the limit of the sequence.

PREREQUISITES
  • Understanding of recurrence relations
  • Familiarity with the Monotone Convergence Theorem
  • Knowledge of limits in sequences
  • Ability to manipulate algebraic expressions
NEXT STEPS
  • Analyze the difference xn+1 - xn to establish monotonicity
  • Study the implications of the Monotone Convergence Theorem in detail
  • Explore examples of bounded sequences to reinforce understanding
  • Investigate the concept of limits in recursive sequences
USEFUL FOR

Mathematics students, particularly those studying real analysis or sequences, and educators seeking to clarify the convergence of recursive sequences.

tallandpoofy
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Homework Statement



Let x1 > 9000, and

xn+1 = )2009xn + 2010)/2011 for n >1

show that (xn) converges and find its limit


Homework Equations



Definition of a limit, Monotone Convergence Theorem.

The Attempt at a Solution



Since xn+1 is monotone for n>1 and bounded, then it converges by Monotone Convergence Theorem.

How do i prove monotone for this function?
I tried xn+2 - xn+1 < 0 but it does not work since xn+1 is dependent on xn
 
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tallandpoofy said:

Homework Statement



Let x1 > 9000, and

xn+1 = )2009xn + 2010)/2011 for n >1

show that (xn) converges and find its limit


Homework Equations



Definition of a limit, Monotone Convergence Theorem.

The Attempt at a Solution



Since xn+1 is monotone for n>1 and bounded, then it converges by Monotone Convergence Theorem.

How do i prove monotone for this function?
I tried xn+2 - xn+1 < 0 but it does not work since xn+1 is dependent on xn

You should be able to use your approach to prove monotonicity. Compute nth term minus (n+1)th term in terms of nth term (equivalent to your suggestion). Then analyze under what conditions it is positive (meaning sequence is monotonically decreasing). This analysis should also give you a clue about the limit.
 

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