Mathematics (Sep 2020)
On the Difference of Coefficients of Starlike and Convex Functions
Abstract
Let f be analytic in the unit disk D={z∈C:|z|1}, and S be the subclass of normalized univalent functions given by f(z)=z+∑n=2∞anzn for z∈D. Let S*⊂S be the subset of starlike functions in D and C⊂S the subset of convex functions in D. We give sharp upper and lower bounds for |a3|−|a2| for some important subclasses of S* and C.
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