IsLocalMax.hasDerivAt_eq_zero

∀ {f : ℝ → ℝ} {f' a : ℝ}, IsLocalMax f a → HasDerivAt f f' a → f' = 0

Fermat's Theorem: the derivative of a function at a local maximum equals zero.

Defined in: Mathlib.Analysis.Calculus.LocalExtr.Basic
Cited by: 2 results in Mathlib
Foundations: Depth 172 from the axioms · uses propext, Classical.choice, Quot.sound

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