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http://dx.doi.org/10.7468/jksmeb.2014.21.2.141

COMPLETE MONOTONICITY OF A DIFFERENCE BETWEEN THE EXPONENTIAL AND TRIGAMMA FUNCTIONS  

Qi, Feng (College of Mathematics, Inner Mongolia University for Nationalities)
Zhang, Xiao-Jing (The 59th Middle School)
Publication Information
The Pure and Applied Mathematics / v.21, no.2, 2014 , pp. 141-145 More about this Journal
Abstract
In the paper, by directly verifying an inequality which gives a lower bound for the first order modified Bessel function of the first kind, the authors supply a new proof for the complete monotonicity of a difference between the exponential function $e^{1/t}$ and the trigamma function ${\psi}^{\prime}(t)$ on (0, ${\infty}$).
Keywords
complete monotonicity; completely monotonic function; integral representation; difference; exponential function; trigamma function; inequality; modifid Bessel function of the fist kind;
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