摘要

Let a and b be two real numbers and f be a positive and differentiable function on an interval L The authors establish the i-log-convex or i-log-concave properties for i is an element of N of the function [f (bx)](a)/[f (ax)](b) for ax is an element of I and bx is an element of I when the function u(k-1) [In f (u)]((k)) for k is an element of N is monotonic and apply these properties to deduce some known and new conclusions related to some special functions, such as the gamma function, Riemann's zeta function, complete elliptic integrals, exponential mean, and extended mean values.