Let $U \subset \mathbb{R}^n$ open. If $f: U \to \mathbb{R}$ attains a relative maximum ( or minimum) in the point $x \in U$, and $f$ is differentiable in point $x$, then $f'(x)=0$.
Prove that $f'(x)=0$
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real-analysis
analysis
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0I believe you may be right. But it's relative max, not max relative, at least for most writers of texts. – 2012-10-18
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0feel free to correct my text ... i am Brazilian and not the domino english – 2012-10-18
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0I agree--I was being a bit picky. It seems I like to see the right terminology. But I knew what you meant, and made a reply about the question in one of the "answers". – 2012-10-18