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Topic: counter example calculus
Replies: 8   Last Post: Aug 5, 2013 4:29 AM

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 gaya.patel@gmail.com Posts: 160 Registered: 11/29/05
Re: counter example calculus
Posted: Aug 4, 2013 2:43 PM

On Sunday, August 4, 2013 2:35:12 PM UTC-4, Arturo Magidin wrote:
> On Sunday, August 4, 2013 9:53:36 AM UTC-5, G Patel wrote:
>

> > Is there a counter example to:
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> > "A function cannot be differentiable on a closed interval of its domain"
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> > (Note, I mean two sided, regular derivatives)
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> This is unclear to me. To me, a counterexample to this statement would be a function f whose domain includes a closed interval [a,b] such that f' exists on all points of [a,b]. But this is trivial (e.g., a constant function).
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> So what, exactly, do you mean? Or, what would "a counterexample" be? A function with *what precise properties*?
>

Ok I have to refine my question (it was incorrectly stated). Sorry.

: Is there a function that is DEFINED on an interval that extends a closed interval [a,b] both on its left and right, where the function is differentiable on [a,b] but not on the extensions.

: How about if I change DEFINED to CONTINUOUS?

{My line of thinking is that it would be hard to find these examples because the derivative is a two sided limit}

Date Subject Author
8/4/13 gaya.patel@gmail.com
8/4/13 magidin@math.berkeley.edu
8/4/13 gaya.patel@gmail.com
8/4/13 magidin@math.berkeley.edu
8/4/13 Virgil
8/5/13 Roland Franzius
8/5/13 Virgil
8/5/13 Roland Franzius
8/5/13 Virgil