I want to compute the subdifferential of $ f $ on $ \mathbb{R} \setminus \{ 0 \} $ when $ f(x) = |x| $. How do I do this?
How to find subdifferential of $|x|$
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functional-analysis
1 Answers
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On $\mathbb{R}^*$, $f$ is differentiable so $\partial f(x)=\{f'(x)\}$ with $f'(x)$ the differential of $f$ at $x$.
You can also see Subdifferential of a finite dimensional function.