Let f(x) = x if x rational and f(x) = 0 if x is irrational(adsbygoogle = window.adsbygoogle || []).push({});

Let g(x) = x^2 if x rational and g(x) = 0 if x is irrational.

Both functions are continuous at 0 and discontinuous at each x != 0.

How do I show that f is not differentiable at 0?

How should I show that g is differentiable at 0? Give g'(0) as well.

Thanks...

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# Differentiability of weird function

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