Theorems · Theorem · real analysis
eventually_nhdsWithin_sign_eq_of_deriv_neg
∀ {f : ℝ → ℝ} {x₀ : ℝ}, deriv f x₀ < 0 → f x₀ = 0 → ∀ᶠ (x : ℝ) in nhds x₀, SignType.sign (f x) = SignType.sign (x₀ - x)If the derivative of f is negative at a root x₀ of f, then locally the sign of f x
matches x₀ - x.
- Defined in
- Mathlib.Analysis.Calculus.DerivativeTest
- Cited by
- 0 results in Mathlib
- Foundations
- Depth 179 from the axioms · uses propext, Classical.choice, Quot.sound
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Cites12
Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.
- DFunLike.coestatement and proof · cited by 62,936
- Realstatement and proof · cited by 25,697
- nhdsstatement and proof · cited by 5,554
- Filter.Eventuallystatement and proof · cited by 3,134
- OrderHomstatement · cited by 934
- derivstatement and proof · cited by 676
- SignTypestatement · cited by 318
- neg_subproof · cited by 272
- SignType.signstatement and proof · cited by 128
- Left.sign_negproof · cited by 9
- deriv.fun_neg'proof · cited by 8
- eventually_nhdsWithin_sign_eq_of_deriv_posproof · cited by 2
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