epsilon delta limit proofs

[danielS]

Hi, my name is Daniel. I am in first semester calculus, and the teacher is very disorganized and skips sections whenever he cares to. Earlier in the semester he skipped the section on epsilon/delta limit proofs. By reading the book, I was able to understand the idea of finding d as a function of e such that for any e > 0, there is a corresponding e that satisfies |f(x)-L| < e if 0 |x-a| < d

and that this refers to the distances on the f and x axes...

 

The problem is not with my understanding of epsilon delta proofs, so much as it is the techniques that the book uses to proove them. It only has a few examples, and the techniques seem very diverse and random, with very little methodology. He is not going to include anything he skips on tests, but I don't like not knowing what I'm paying to learn. Can anybody help?

[Dave]

I know the feeling Epsilon-delta proofs don't really seem like proofs, but once you start playing around with some examples it gets a lot easier.

 

If you post some examples on here, then I'll try and answer them as well as I can (same for others), but it's really hard to try and teach someone a complete subject through the internet.

[nfornick]

Can you try this?

 

(x+3)/(x^2-3) as x -> infinity

 

I know the feeling Epsilon-delta proofs don't really seem like proofs' date=' but once you start playing around with some examples it gets a lot easier.

 

If you post some examples on here, then I'll try and answer them as well as I can (same for others), but it's really hard to try and teach someone a complete subject through the internet.[/quote']

[Dave]

Using epsilon-delta? A much easier way is to prove the quotient rule