- #1

Derek Hart

- 14

- 1

## Homework Statement

Give an example to show that the given "definition" of lim

_{x→a}ƒ(x) = L is incorrect.

Definition: For each 0<δ there is an 0<ε such that if 0< l x-a I < δ , then I ƒ(x) - L I < ε .

## Homework Equations

## The Attempt at a Solution

I considered the piece-wise function: ƒ(x) = (0 if x<0) = ( λ if x>0). I then chose an ε such that ε > I λ/2 I , and chose L = λ/2.

It is obviously true that for each positive δ , if 0 < I x-0 I < δ , then I ƒ(x) - λ/2 I < ε . But, by our definition, this means that lim

_{x→0}ƒ(x) = λ/2 , which is blatantly false.

Is this sufficient? I think that spivak is expecting that I use some sort of "common sense" in my argument such as in my final statement.