42 papers found.

Use AND, OR, NOT, +word, -word, "long phrase", (parentheses) to fine-tune your search.

Use AND, OR, NOT, +word, -word, "long phrase", (parentheses) to fine-tune your search.

In this paper, the necessary and suffcient conditions for the converses of comparison inequalities for Stolarsky means and for Gini means to hold are proved, and the necessary and suffcient conditions for some companion inequalities for bivariate means to hold are given, which unify, generalize and improve known results.

In this paper, by using the properties of an auxiliary function, we mainly present the necessary and sufficient conditions for various ratios constructed by gamma functions to be respectively completely and logarithmically completely monotonic. As consequences, these not only unify and improve certain known results including Qi’s and Ismail’s conclusions, but also can generate...

In the article, we present the necessary and sufficient condition for the parameter p on the interval ( 7 / 5 , ∞ ) such that the function x → erf ( x ) / B p ( x ) is strictly increasing (decreasing) on ( 0 , ∞ ) , and find the best possible parameters p, q on the interval ( 7 / 5 , ∞ ) such that the double inequality B p ( x ) < erf ( x ) < B q ( x ) holds for all x > 0 , where...

Let ψ n = ( − 1 ) n − 1 ψ ( n ) ( n = 0 , 1 , 2 , … ), where ψ ( n ) denotes the psi and polygamma functions. We prove that for n ≥ 0 and two different real numbers a and b, the function x ↦ ψ n − 1 ( ∫ a b ψ n ( x + t ) d t b − a ) − x is strictly increasing from ( − min ( a , b ) , ∞ ) onto ( min ( a , b ) , ( a + b ) / 2 ) , which generalizes a well-known result. As an...

In the article, we provide the necessary and sufficient conditions for the parameters α and β such that the generalized Wilker-type inequality 2 β α + 2 β ( sin x x ) α + α α + 2 β ( tan x x ) β − 1 > ( < ) 0 holds for all x ∈ ( 0 , π / 2 ) . MSC: 26D05, 33B10.

In this paper, we present the monotonicity and absolute monotonicity properties for the two-parameter hyperbolic and trigonometric functions. As applications, we find several complete monotonicity properties for the functions involving the gamma function and provide the bounds for the error function. MSC: 33B10, 33B15, 33B20, 26A48, 26D07.

In the article, we discuss the monotonicity properties of the function x → ( 1 − e − a x p ) 1 / p / ∫ 0 x e − t p d t for a , p > 0 with p ≠ 1 on ( 0 , ∞ ) and prove that the double inequality Γ ( 1 + 1 / p ) ( 1 − e − a x p ) 1 / p < ∫ 0 x e − t p d t < Γ ( 1 + 1 / p ) ( 1 − e − b x p ) 1 / p holds for all x > 0 if and only if a ≤ min { 1 , Γ − p ( 1 + 1 / p ) } and b ≥ max { 1...

In the article, we deal with the monotonicity of the function x → [ ( x p + a ) 1 / p − x ] / I p ( x ) on the interval ( 0 , ∞ ) for p > 1 and a > 0 , and present the necessary and sufficient condition such that the double inequality [ ( x p + a ) 1 / p − x ] / a < I p ( x ) < [ ( x p + b ) 1 / p − x ] / b for all x > 0 and p > 1 , where I p ( x ) = e x p ∫ x ∞ e − t p d t is...

In the article, we prove that the function r ↦ E ( r ) / S 9 / 2 − p , p ( 1 , r ′ ) is strictly increasing on ( 0 , 1 ) for p ≤ 7 / 4 and strictly decreasing on ( 0 , 1 ) for p ∈ [ 2 , 9 / 4 ] , where r ′ = 1 − r 2 , E ( r ) = ∫ 0 π / 2 1 − r 2 sin 2 ( t ) d t is the complete elliptic integral of the second kind, and S p , q ( a , b ) = [ q ( a p − b p ) / ( p ( a q − b q...

In the article, we present several sharp bounds for the modified Bessel function of the first kind I 0 ( t ) = ∑ n = 0 ∞ t 2 n 2 2 n ( n ! ) 2 and the Toader-Qi mean T Q ( a , b ) = 2 π ∫ 0 π / 2 a cos 2 θ b sin 2 θ d θ for all t > 0 and a , b > 0 with a ≠ b . MSC: 33C10, 26E60.

October 2015; Revised 10 December 2015; Accepted 24 December 2015
Academic Editor: Kehe Zhu
Copyright © 2016 **Zhen**-**Hang** **Yang** and Yu-Ming Chu. This is an open access article distributed under the Creative

October 2015; Revised 10 December 2015; Accepted 24 December 2015
Academic Editor: Kehe Zhu
Copyright © 2016 **Zhen**-**Hang** **Yang** and Yu-Ming Chu. This is an open access article distributed under the Creative

In the article, we establish several Lazarević and Cusa type inequalities involving the hyperbolic sine and cosine functions with two parameters. As applications, we find some new bounds for certain bivariate means. MSC: 26D05, 26D07, 33B10, 26E60.

In the article, we establish several inequalities for the Ramanujan constant function R ( x ) = − 2 γ − ψ ( x ) − ψ ( 1 − x ) on the interval ( 0 , 1 / 2 ] , where ψ ( x ) is the classical psi function and γ = 0.577215 ⋯ is the Euler-Mascheroni constant. MSC: 33B15, 26D07.

In the article, we present certain p , q ∈ R such that the Wilker-type inequalities 2 q p + 2 q ( sin x x ) p + p p + 2 q ( tan x x ) q > ( < ) 1 and ( π 2 ) p ( sin x x ) p + [ 1 − ( π 2 ) p ] ( tan x x ) q > ( < ) 1 hold for all x ∈ ( 0 , π / 2 ) . MSC: 26D05, 33B10.

In this paper, we present the sharp bounds of the ratios U ( a , b ) / L 4 ( a , b ) , P 2 ( a , b ) / U ( a , b ) , N S ( a , b ) / P 2 ( a , b ) and B ( a , b ) / N S ( a , b ) for all a , b > 0 with a ≠ b , where L 4 ( a , b ) = [ ( b 4 − a 4 ) / ( 4 ( log b − log a ) ) ] 1 / 4 , U ( a , b ) = ( b − a ) / [ 2 arctan ( ( b − a ) / 2 a b ) ] , P 2 ( a , b ) = [ ( b 2 − a 2...

In the article, we present several sharp bounds for the Mills ratio R ( x ) = e x 2 / 2 ∫ x ∞ e − t 2 / 2 d t ( x > 0 ) in terms of the functions I a ( x ) = a / [ x 2 + 2 a + ( a − 1 ) x ] and J ( x ) = a / [ x 2 + 2 a 2 / π + 2 a x / π ] with parameter a > 0 . MSC: 60E15, 26A48, 26D15.

In this paper, we present the best possible parameters p and q such that the double inequality M p ( a , b ) < V ( a , b ) < M q ( a , b ) holds for all a , b > 0 with a ≠ b , where M r ( a , b ) = [ ( a r + b r ) / 2 ] 1 / r ( r ≠ 0 ) and M 0 ( a , b ) = a b is the rth power mean and V ( a , b ) = ( a − b ) / [ 2 sinh − 1 ( ( a − b ) / 2 a b ) ] is the second Yang mean. MSC: 26E60.

Received 3 August 2014; Accepted 2 September 2014
Academic Editor: Kehe Zhu
Copyright © 2015 **Zhen**-**Hang** **Yang** and Yu-Ming Chu. This is an open access article distributed under the Creative Commons

Received 3 August 2014; Accepted 2 September 2014
Academic Editor: Kehe Zhu
Copyright © 2015 **Zhen**-**Hang** **Yang** and Yu-Ming Chu. This is an open access article distributed under the Creative Commons