Epsilon-Delta Proofs: Understanding the Process

In summary, when performing epsilon-delta proofs, it is common to first make suggestive calculations to help find the appropriate value for delta in terms of epsilon. However, it is important to then go back and ensure that this value actually works. While it is possible to guess the value of delta and then show its validity, it is often more concise to reorganize the proof in a way that makes the delta appear naturally. This is primarily done for stylistic purposes.
  • #1
David_Vancouver
4
0
Hi,

Why is it, that when ever epsilon-delta proofs are done, once delta is found in terms of epsilon, it is reinputed through again? Is there any point to this really?
 
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  • #2
The idea is that you make some suggestive calculations to help you find what delta should be. Then you have to go back and make sure it actually works. If you were clever, you could guess delta and then show it works, and skip the finding delta part.
 
  • #3
But aren't those suggestive calculations definitive? That is, they are always true?
 
  • #4
It's not necessary to reorganize your proof in a way that makes the delta magically appear from thin air, but it often makes a shorter proof. It's mostly for style reasons.
 

Related to Epsilon-Delta Proofs: Understanding the Process

1. What are epsilon-delta proofs?

Epsilon-delta proofs are a mathematical technique used to prove the existence of a limit in calculus. They involve using the concepts of "epsilon" and "delta" to show that as x approaches a certain value, the corresponding y values approach a specific limit.

2. Why are epsilon-delta proofs important?

Epsilon-delta proofs are important because they provide a rigorous and precise way of proving the existence of limits, which is a fundamental concept in calculus. They also help to solidify understanding of the relationship between a function's behavior and its limit at a given point.

3. How do you use epsilon-delta proofs?

To use epsilon-delta proofs, you first start with the definition of a limit and then use algebraic manipulation and logical reasoning to manipulate the inequality in the definition to eventually arrive at a statement involving epsilon and delta. This statement can then be used to determine the appropriate value of delta for a given epsilon, proving the existence of the limit.

4. Are there any tips for understanding epsilon-delta proofs?

Some tips for understanding epsilon-delta proofs include practicing with different types of functions, breaking the proof down into smaller steps, and using visual aids like graphs to help understand the concepts. It is also important to have a solid understanding of algebra and inequalities.

5. Can epsilon-delta proofs be used for any function?

Yes, epsilon-delta proofs can be used for any function as long as the function is continuous at the point in question. If a function is not continuous, then epsilon-delta proofs cannot be used to prove the existence of a limit at that point.

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