한국수학교육학회지시리즈B:순수및응용수학 (The Pure and Applied Mathematics)
- 제12권3호
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- Pages.229-235
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- 2005
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- 1226-0657(pISSN)
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- 2287-6081(eISSN)
ON SPHERICALLY CONCAVE FUNCTIONS
초록
The notions of spherically concave functions defined on a subregion of the Riemann sphere P are introduced in different ways in Kim & Minda [The hyperbolic metric and spherically convex regions. J. Math. Kyoto Univ. 41 (2001), 297-314] and Kim & Sugawa [Charaterizations of hyperbolically convex regions. J. Math. Anal. Appl. 309 (2005), 37-51]. We show continuity of the concave function defined in the latter and show that the two notions of the concavity are equivalent for a function of class