Solving Epsilon-Delta Proof: Homework Statement

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SUMMARY

The discussion focuses on solving the epsilon-delta proof for the limit of the function (6x-7) as x approaches 3, which equals 11. The user correctly identifies the need to establish a relationship between ε and δ, specifically setting δ = ε/6. The proof demonstrates that if δ is chosen as ε/6, then the condition |(6x-7)-11| < ε holds true when 0 < |x-3| < δ. This confirms the limit as required by the epsilon-delta definition.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with epsilon-delta definitions
  • Basic algebraic manipulation skills
  • Knowledge of inequalities and absolute values
NEXT STEPS
  • Study the formal definition of limits using epsilon-delta proofs
  • Practice additional epsilon-delta problems for various functions
  • Explore continuity and differentiability concepts in calculus
  • Learn about the implications of limits in real analysis
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Students studying calculus, particularly those learning about limits and epsilon-delta proofs, as well as educators looking for examples to illustrate these concepts.

appplejack
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Homework Statement


I just want to make sure I include all the steps in doing this:

lim (6x-7) = 11
x->3


Homework Equations





The Attempt at a Solution


given ε>0, we need to find a δ>0, such that 0< lx-3l < δ then 0 < l (6x-7)-11 l < ε
To prove this I need to make 0 < l (6x-7)-11 l < ε look like 0< lx-3l < δ

1. l 6x-18 l < ε = l x-3 l < ε/6

2. let δ = ε/6

3. lx-3l < δ = > lx-3l < ε/6

This still doesn't feel like I proved something but was there something that I missed?
 
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What you have proved is that if δ=ε/6 then lx-3l<δ -> |(6x-7)-11|<ε. That should really be your last line. And, yes, that proves your limit.
 

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