(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

If f: R->R is differentiable at c in R, show that:

f'(c)=lim(n{f(c+1/n)-f(c)})

Show by example that the existance of this sequence doesn't imply the existence of f'(c)

3. The attempt at a solution

I got the second part, with my example just being |x|, but i'm not sure about the first part.

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# Homework Help: Existance of this sequence

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