TY - EJOU AU - Anis, Mona AU - Almuashi, Hanan AU - Mahmoud, Mansour TI - Complete Monotonicity of Functions Related to Trigamma and Tetragamma Functions T2 - Computer Modeling in Engineering \& Sciences PY - 2022 VL - 131 IS - 1 SN - 1526-1506 AB - In this paper, we study the completely monotonic property of two functions involving the function △(x) = and deduce the double inequality , x > 0
which improve some recent results, where ψ(x) is the logarithmic derivative of the Gamma function. Also, we deduce the completely monotonic degree of a function involving ψ'(x). KW - Trigamma function; tetragamma function; completely monotonic function; completely monotonic degree; inequality DO - 10.32604/cmes.2022.016927