V.13 N.1 2022

  • TWO MONOTONIC FUNCTIONS DEFINED BY TWO DERIVATIVES OF A FUNCTION INVOLVING TRIGAMMA FUNCTION
    FENG QI (pp. 91-104)

    • Abstract.

    In the paper, by virtue of the convolution theorem for the Laplace transforms, with the help of monotonicity and logarithmic concavity of a function involving exponential function, and by means of analytic techniques, the author presents necessary and sufficient conditions for two functions defined by two derivatives of a function involving trigamma function to be completely monotonic or monotonic.

    Keywords:

    complete monotonicity, monotonicity, necessary and sufficient condition, trigamma function, derivative, convolution theorem, Laplace transforms, exponential function, logarithmic concavity, inequality.

    Contact Details

    Telephone:
    Email: twms.aliev@gmail.com
    Website: www.twmsj.az

    Z.Khalilov str., 23, AZ 1148,
    Baku
    AZERBAIJAN