Need help understanding this math definition.

BamBam215

Golden Member
Feb 17, 2000
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It's a course in real analysis and we are on sequences. The definition of the limit of a sequence follows:

e = epsilon

A sequence X=(xsubn) in R (real) is said to converge to x in R, or x is said to be a limit of (xsubn), if for every e > 0 there exists a natural number K(e) such that for all n>=K(e), the terms xsubn satisfies | xsubn - x | < e


I am KINDA getting it but then i am not 100% sure. I know that I will use this definition through the rest of the chapter so I want to clearly understand it before moving on. I understand that basically if any e > 0 is picked, the difference between the limit x and the value xsubn would still be smaller than that epsilon that was picked. This pretty much gaurantees that xsubn and x are so closed that x must be the limit. But what is the deal with picking K???
 

Kev

Lifer
Dec 17, 2001
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this is why i stopped taking math. i could probably understand stuff like this but i just don't have the attention span
 

Kelemvor

Lifer
May 23, 2002
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Once I got so high in Math classes that we weren't using ny number anymore, I bailed out.
 

BamBam215

Golden Member
Feb 17, 2000
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got a quiz in an hr and i'm still clueless as to picking a value K. someone plz clarify :(