In this paper, the authors show some monotonicity and concavity of the classical psi function, by which several known results are improved and some new asymptotically sharp estimates are obtained for this function. In...In this paper, the authors show some monotonicity and concavity of the classical psi function, by which several known results are improved and some new asymptotically sharp estimates are obtained for this function. In addition, applying the new results to the psi function, the authors improve the well-known lower and upper bounds for the approximate evaluation of Euler＇s constant γ.展开更多
Abstract This paper is devoted to the study of the period function for a class of reversible quadratic system x=-2xy,y=k-1-2kx＋（k＋1）x^2-1/2y^2.We determine the monotonicity of the period function for each k ∈ R....Abstract This paper is devoted to the study of the period function for a class of reversible quadratic system x=-2xy,y=k-1-2kx＋（k＋1）x^2-1/2y^2.We determine the monotonicity of the period function for each k ∈ R. It is proved that the period function has at most one critical point.展开更多
We studied the monotonicity and Convexity properties of the new functions involving the gamma function, and get the general conclusion that Minc-Sathre and C. P. Chen-G. Wang’s inequality are extended and refined.
基金Supported by the National Natural Science Foundation of China(11171307)
文摘In this paper, the authors show some monotonicity and concavity of the classical psi function, by which several known results are improved and some new asymptotically sharp estimates are obtained for this function. In addition, applying the new results to the psi function, the authors improve the well-known lower and upper bounds for the approximate evaluation of Euler＇s constant γ.
文摘Abstract This paper is devoted to the study of the period function for a class of reversible quadratic system x=-2xy,y=k-1-2kx＋（k＋1）x^2-1/2y^2.We determine the monotonicity of the period function for each k ∈ R. It is proved that the period function has at most one critical point.
文摘We studied the monotonicity and Convexity properties of the new functions involving the gamma function, and get the general conclusion that Minc-Sathre and C. P. Chen-G. Wang’s inequality are extended and refined.
