HANKEL DETERMINANT OF THIRD ORDER FOR THE INVERSE OF RECIPROCAL OF BOUNDED TURNING FUNCTIONS

Abstract

The objective of this paper is to obtain the best possible upper bound to the third order Hankel determinant for the inverse of the function f, when f belongs to the reciprocal of bounded turning functions. The result, obtained through this paper is far better than the result obtained by the authors (see [26]), who had worked on this problem earlier.