Hacettepe Journal of Mathematics and Statistics 2651-477X 2651-477X Hacettepe University 10.15672/HJMS.2018.637 Mathematical Sciences Matematik Harmonic functions with missing coefficients https://orcid.org/0000-0003-1482-1080 Dziok Jacek University of Rzeszów 12 08 2019 48 6 1778 1791 04 13 2018 07 24 2018 Copyright © 2002, Hacettepe Journal of Mathematics and Statistics 2002 Hacettepe Journal of Mathematics and Statistics

In the paper we introduce the classes of functions with missing coefficients defined by generalized Ruscheweyh derivatives and we show that they can be presented as dual sets. Moreover, by using extreme points theory, we obtain estimations of classical convex functionals on the defined classes of functions. Some applications of the main results are also considered.

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