Integral Inequalities for Mappings Whose Derivatives Are s-Convex in the Second Sense and Applications to Special Means for Positive Real Numbers
MEVLÜT TUNÇ1,, SEVIL BALGEÇTİ1
1Mustafa Kemal University, Faculty of Science and Arts, Department of Mathematics, Hatay, Turkey
Abstract
In this paper, the authors establish a new type integral inequalities for differentiable s-convex functions in the second sense. By the well-known Hölder inequality and power mean inequality, they obtain some integral inequalities related to the s-convex functions and apply these inequalities to special means for positive real numbers.
Keywords: s-convexity, Hermite-Hadamard Inequality, Bullen’s inequality, Special Means.
Received May 07, 2015; Revised April 21, 2016; Accepted April 29, 2016
Copyright © 2016 Science and Education Publishing. All Rights Reserved.Cite this article:
- MEVLÜT TUNÇ, SEVIL BALGEÇTİ. Integral Inequalities for Mappings Whose Derivatives Are s-Convex in the Second Sense and Applications to Special Means for Positive Real Numbers. Turkish Journal of Analysis and Number Theory. Vol. 4, No. 2, 2016, pp 48-53. https://pubs.sciepub.com/tjant/4/2/5
- TUNÇ, MEVLÜT, and SEVIL BALGEÇTİ. "Integral Inequalities for Mappings Whose Derivatives Are s-Convex in the Second Sense and Applications to Special Means for Positive Real Numbers." Turkish Journal of Analysis and Number Theory 4.2 (2016): 48-53.
- TUNÇ, M. , & BALGEÇTİ, S. (2016). Integral Inequalities for Mappings Whose Derivatives Are s-Convex in the Second Sense and Applications to Special Means for Positive Real Numbers. Turkish Journal of Analysis and Number Theory, 4(2), 48-53.
- TUNÇ, MEVLÜT, and SEVIL BALGEÇTİ. "Integral Inequalities for Mappings Whose Derivatives Are s-Convex in the Second Sense and Applications to Special Means for Positive Real Numbers." Turkish Journal of Analysis and Number Theory 4, no. 2 (2016): 48-53.
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1. Introduction
1.1. DefinitionsDefinition 1. [10] A function is said to be convex on
if inequality
![]() | (1.1) |
holds for all and
We say that
is concave if
is convex.
Definition 2. [8] Let A function
is said to be s-convex in the second sense if
![]() | (1.2) |
for all and
This class of s-convex functions is usually denoted by
Certainly, s-convexity means just ordinary convexity when s = 1.
1.2. TheoremsTheorem 1. The Hermite-Hadamard inequality: Let be a convex function and
with
The following double inequality:
![]() | (1.3) |
is known in the literature as Hadamard’s inequality (or Hermite-Hadamard inequality) for convex functions. If is a positive concave function, then the inequality is reversed.
Theorem 2. [6] Suppose that is an s-convex function in the second sense, where
and let
,
. If
then the following inequalities hold:
![]() | (1.4) |
The constant is the best possible in the second inequality in (1.4). The above inequalities are sharp. If
is an s-concave function in the second sense, then the inequality is reversed.
Theorem 3. Let be a convex function on the interval
of real numbers and
with
The inequality
![]() |
is known as Bullen’s inequality for convex functions [[5], p.39].
In [4], Dragomir and Agarwal obtained inequalities for differentiable convex mappings which are connected to Hadamard’s inequality, as follow:
Theorem 4. Let be a differentiable mapping on
, where
, with
If
is convex on [a; b], then the following inequality holds:
![]() | (1.5) |
In [11], Pearce and Pečarić obtained inequalities for differentiable convex mappings which are connected with Hadamard’s inequality, as follow:
Theorem 5. Let be differentiable mapping on
, where
, with
If
is convex on
for some
, then the following inequality holds:
![]() | (1.6) |
If is concave on
for some
then
![]() | (1.7) |
In [1], Alomari, Darus and Kırmacı obtained inequalities for differentiable s-convex and concave mappings which are connected with Hadamard’s inequality, as follow:
Theorem 6. Let be differentiable mapping on
such that
, where
with
If
is concave on
for some fixed
then the following inequality holds:
![]() | (1.8) |
In [12], Tunç and Balgeçti obtained inequalities for differentiable convex functions which are connected with a new type integral inequality, as follow:
Lemma 1. Le be a differentiable function on
If
then
![]() | (1.9) |
for each and
Theorem 7. [12] Let be a differentiable function on
If
is convex on
, then
![]() | (1.10) |
for each
Theorem 8. [12] Let R be a differentiable function on
If
is convex on
and
with
then
![]() | (1.11) |
Theorem 9. [12] Let be a differentiable function on
If
is convex on
and
, then
![]() | (1.12) |
For recent results and generalizations concerning Hadamard’s inequality and concepts of convexity and s-convexity see [1-12][1] and the references therein.
Throughout this paper we will use the following notations and conventions. Let and
with
and
and
![]() |
![]() |
be the arithmetic mean, geometric mean, generalized logarithmic mean for respectively.
2. Inequalities for s-convex Functions and Applications
Theorem 10. Let be a differentiable function on
If
is s-convex on
for some fixed
then
![]() | (2.1) |
for each
Proof. Using Lemma 1 and from properties of modulus, and since is s-convex on J, then we obtain
![]() |
Proposition 1. Let
and
then
![]() | (2.2) |
Proof. The proof follows from (2.1) applied to the s-convex function and
Proposition 2. Let
then
![]() | (2.3) |
Proof. The proof follows from (2.1) applied to the s-convex function and
with
Remark 1. In (2.1), (2.2), if we take then (2.1), (2.2) reduces to (1.10), [[12], Proposition 2], respectively.
Theorem 11. Let be a differentiable function on
If
is s-convex on
for some fixed
and
with
then
![]() | (2.4) |
for each
Proof. Using Lemma 1 and from properties of modulus, and since is s-convex on J, then we obtain
![]() | (2.5) |
Since is s-convex, by the Hölder inequality, we have
![]() | (2.6) |
and
![]() | (2.7) |
It can be easily seen that
![]() | (2.8) |
If expressions (2.6)-(2.8), we obtain
![]() |
The proof is completed.
Proposition 3. Let
and
, then
![]() | (2.9) |
Proof. The proof follows from (2.4) applied to the s-convex function and
Proposition 4. Let
and
, then
![]() | (2.10) |
Proof. The proof follows from (2.4) applied to the s-convex function and
Remark 2. In (2.4), (2.9), if we take then (2.4), (2.9) reduces to (1.11), [[12], Proposition 5], respectively.
Theorem 12. Let be a differentiable function on
. If
is s-convex on
for some fixed
and
then
![]() | (2.11) |
Proof. From Lemma 1 and using the well-known power mean inequality and since is s-convex on
, we can write
![]() |
![]() |
The proof is completed.
Proposition 5. Let
and
, then
![]() | (2.12) |
Proof. The proof follows from (2.11) applied to the s-convex function and
Proposition 6. Let
and
, then
![]() | (2.13) |
Proof. The proof follows from (2.11) applied to the s-convex function and
Remark 3. In (2.11), (2.12), if we take , then (2.11), (2.12) reduces to (1.12), [[12], Proposition 8] respectively.
References
[1] | M. Alomari, M. Darus, U.S. Kırmacı, Some Inequalities of Hermite-Hadamard type for s-convex Functions, Acta Math. Sci. 31B(4):1643-1652 (2011). | ||
![]() | View Article | ||
[2] | P. Burai, A. Házy, and T. Juhász, Bernstein-Doetsch type results for s-convex functions, Publ. Math. Debrecen 75 (2009), no. 1-2, 23-31. | ||
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[3] | P. Burai, A. Házy, and T. Juhász, On approximately Breckner s-convex functions, Control Cybernet. 40 (2011), no. 1, 91-99. | ||
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[4] | S.S. Dragomir, R.P. Agarwal, Two inequalities for differentiable mappings and applications to special means of real numbers and to trapezoidal formula, Appl. Math. Lett. 11 (1998) 91-95. | ||
![]() | View Article | ||
[5] | S. S. Dragomir and C. E. M. Pearce: Selected topics on Hermite-Hadamard inequalities and applications, RGMIA monographs, Victoria University, 2000. [Online:https://www.sta¤.vu.edu.au/RGMIA/monographs/hermite-hadamard.html]. | ||
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[6] | S.S. Dragomir, S. Fitzpatrick, The Hadamard’s inequality for s-convex functions in the second sense, Demonstration Math., 32 (4) (1999), 687-696. | ||
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[7] | J. Hadamard, Étude sur les propriétés des fonctions entières en particulier d.une function considérée par Riemann, J. Math. Pures Appl. 58 (1893) 171-215. | ||
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[8] | H. Hudzik and L. Maligranda, Some remarks on s-convex functions, Aequationes Math., 48, 100-111, (1994). | ||
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[9] | D.S. Mitrinović, I.B. Lacković, Hermite and convexity, Aequationes Math. 28 (1985) 229-232. | ||
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[10] | D. S. Mitrinović, J. Peµcarić, and A.M. Fink, Classical and new inequalities in analysis, KluwerAcademic, Dordrecht, 1993. | ||
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[11] | C.E.M. Pearce, J. Peµcarić, Inequalities for differentiable mappings with application to special means and quadrature formula, Appl. Math. Lett. 13 (2000) 51-55. | ||
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[12] | M Tunç, S Balgeçti, Some inequalities for differentiable convex functions with applications, https://arxiv.org/pdf/1406.7217.pdf, submitted. | ||
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