11 citations · 26 across the 9 of their papers we have counts for
9 papers
An accurate approximation formula for gamma function
Zhen-Hang Yang, Jing-Feng Tian
In this paper, we present a very accurate approximation for gamma function: \begin{equation*} Γ\left( x+1\right) \thicksim \sqrt{2πx}\left( \dfrac{x}{e}\right) ^{x}\left( x\sinh \f…
Two asymptotic expansions for gamma function developed by Windschitl's formula
Zhen-Hang Yang, Jing-Feng Tian
In this paper, we develop Windschitl's approximation formula for the gamma function to two asymptotic expansions by using a little known power series. In particular, for $n\in \mat…
Convexity and monotonicity for the elliptic integrals of the first kind and applications
Zhen-Hang Yang, Jingfeng Tian
The elliptic integral and its various generalizations are playing very important and basic role in different branches of modern mathematics. It is well known that they cannot be re…
Optimal evaluations for the Sándor-Yang mean by power mean
Zhen-Hang Yang, Yu-Ming Chu
In this paper, we prove that the double inequality a, b>0a\neq bp\leq 4\log 2/(4+2\log 2-π)=1.2351\cdots$ an…
Some sharp Wilker type inequalities and their applications
Zhen-Hang Yang
In this paper, we prove that for fixed , the Wilker type inequality {equation*} \frac{2}{k+2}(\frac{\sin x}{x}) ^{kp}+\frac{k}{k+2}(\frac{% \tan x}{x})^{p}>1 {equation*}%…
Some new inequalities for trigonometric functions and corresponding ones for means
Zhen-Hang Yang
In this paper, the versions of trigonometric functions of certain known inequalities for hyperbolic ones are proved, and then corresponding inequalities for means are presented.