Some inequalities involving the polygamma functions

Abstract Let ψn(x)=(−1)n−1ψ(n)(x) $\psi _{n}(x)=(-1)^{n-1}\psi ^{(n)}(x)$, where ψ(n)(x) $\psi ^{(n)}(x)$ are the polygamma functions. We determine necessary and sufficient conditions for the monotonicity and convexity of the function F(x;α,β)=ln(exp(αψ(x+β))ψn(x))−ln(n−1)!,x>max(0,−β), $$ F(x;\a...

Full description

Bibliographic Details
Main Authors: Lichun Liang, Bin Zhao, Aibing Li
Format: Article
Language:English
Published: SpringerOpen 2019-03-01
Series:Journal of Inequalities and Applications
Subjects:
Online Access:http://link.springer.com/article/10.1186/s13660-019-1999-5