NECESSARY AND SUFFICIENT CONDITIONS FOR COMPLETE MONOTONICITY AND MONOTONICITY OF TWO FUNCTIONS DEFINED BY TWO DERIVATIVES OF A FUNCTION INVOLVING TRIGAMMA FUNCTION

Applicable Analysis and Discrete Mathematics

article

Feng Qi¹ 

[1] Institute of Mathematics Henan Polytechnic University Jiaozuo 454010;School of Mathematical Sciences Tianjin Polytechnic University Tianjin 300387 P. R. China

关键词: polygamma function;    necessary and sufficient condition;    Monotonicity;    inequality;    completely monotonic function;   

DOI  :  10.2298/AADM191111014Q

学科分类：社会科学、人文和艺术（综合）

来源: Univerzitet u Beogradu * Elektrotehnicki Fakultet / University of Belgrade, Faculty of Electrical Engineering

【 摘 要 】

In the paper, by virtue of convolution theorem for the Laplace transforms,Bernstein’s theorem for completely monotonic functions, some properties ofa function involving exponential function, and other analytic techniques, theauthor finds necessary and sufficient conditions for two functions defined bytwo derivatives of a function involving trigamma function to be completelymonotonic or monotonic. These results generalize corresponding known ones.

【 授权许可】

Unknown