Article

    Ufa Mathematical Journal
    Volume 9, Number 2, pp. 109-118

    Third Hankel determinant for the inverse of reciprocal of bounded turning functions has a positive real part of order alpha


    Rani N., Venkateswarlu B.

    DOI:10.13108/2017-9-2-109

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    Let RT be the class of functions f(z) univalent in the unit disk E=z:|z|<1 such that Ref′(z)>0, z∈E, and H3(1) be the third Hankel determinant for inverse function to f(z). In this paper we obtain, first an upper bound for the second Hankel determinant, |t2t3−t4|, and the best possible upper bound for the third Hankel determinant H3(1) for the functions in the class of inverse of reciprocal of bounded turning functions having a positive real part of order alpha.