A Note on Level Sets of Differentiable Functions f(x,y) with Non-Vanishing Gradient
The purpose of this note is to give an alternate proof of a result of M.Elekes. We show that if f : ℝ2 → ℝ is a differentiable function with everywhere non-zero gradient then for every point x ∊ ℝ2 in the level set {x : f(x) = c} there is a neighborhood V of x such that {f = c} ∩ V is homeomorphic t...
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Published in | Real analysis exchange Vol. 43; no. 2; pp. 387 - 392 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
East Lansing
Michigan State University Press
01.01.2018
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Subjects | |
Online Access | Get full text |
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Summary: | The purpose of this note is to give an alternate proof of a result of M.Elekes. We show that if f : ℝ2 → ℝ is a differentiable function with everywhere
non-zero gradient then for every point x ∊ ℝ2 in the level set {x : f(x) = c} there is a neighborhood
V of x such that {f = c} ∩ V is homeomorphic to an open interval or the union of finitely
many open segments passing through a point.
Mathematical Reviews subject classification: Primary: 26B10; Secondary: 26B05
Key words: Implicit Function Theorem, Non-vanishing Gradient, Locally homeomorphic |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 |
ISSN: | 0147-1937 1930-1219 |
DOI: | 10.14321/realanalexch.43.2.0387 |