Proving Cauchy Sequence with Triangle Inequality

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    Cauchy Sequence
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SUMMARY

The discussion focuses on proving that the sequence \( S_n \) is a Cauchy sequence using the triangle inequality. The condition given is \( |S_{n+1} - S_n| < 2^{-n} \) for all natural numbers \( n \). By applying the triangle inequality, the proof involves showing that for any \( m > n \), the sum of the differences \( |S_m - S_n| \) can be bounded, ultimately demonstrating that the sequence converges as required by the definition of a Cauchy sequence.

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  • Understanding of Cauchy sequences in real analysis
  • Familiarity with the triangle inequality
  • Basic knowledge of sequences and limits
  • Experience with mathematical proofs and inequalities
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  • Study the formal definition of Cauchy sequences in real analysis
  • Learn more about the triangle inequality and its applications in proofs
  • Explore convergence criteria for sequences in metric spaces
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Homework Statement



Let Sn be a sequence such that |Sn+1-Sn|< 2-n for all n in the natural numbers

Homework Equations





The Attempt at a Solution



I understand what it means to be cauchy but I'm not sure how to prove this particular sequence is cauchy. Please help!
 
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Use the triangle inequality. For m>n, |S_m-S_n|<=|S_m-S_(m-1)|+|S_(m-1)-S_(m-2)|+...+|S_(n+1)-S_n|.
 

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