摘要
About the accurate value of ψ （ x ） = Γ′ （ x ） / Γ （ x）, we know only ψ （1）and ψ （1/ 2）.In this paper, by calculating the accurate values of some series expansion of a function and applying some skills of complex analysis, we prove that the expression of the ψ-function admits a finite expression in elementary function for rational number z. As an application, some examples are given.
About the accurate value of ψ （ x ） = Γ′ （ x ） / Γ （ x）, we know only ψ （1）and ψ （1/ 2）.In this paper, by calculating the accurate values of some series expansion of a function and applying some skills of complex analysis, we prove that the expression of the ψ-function admits a finite expression in elementary function for rational number z. As an application, some examples are given.
基金
Supported by the National Natural Science Foundation of China (10926128)
