Extremal problems in some classes of holomorphic functions (Q1320081)

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scientific article; zbMATH DE number 554054
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Extremal problems in some classes of holomorphic functions
scientific article; zbMATH DE number 554054

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    Extremal problems in some classes of holomorphic functions (English)
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    19 April 1994
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    The author considers the family of functions which are analytic in the open unit disk, satisfy \(\text{Re} f(z)>0\) for \(| z |<1\), \(f(0) = 1\), \(f^{(k)}(0)\) is real for \(k = 1,2, \dots\) and \(f^{(k)}(0)\) is fixed for \(k=1,2,\dots,n\). The set of extreme points of this family is determined for each permissible value of \(f^{(k)}(0)\) \((k=1,2,\dots,n)\). That information is used to solve certain extremal problems over the family, including maximizing and minimizing \(f(r)\) and \(f'(r)\) where \(0<r<1\). Similar results are derived for the corresponding family of typically-real functions.
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    typically-real functions
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