Keywords: Hermite-Hadamard type inequality, Hölder’s integral inequality, quasi-geometrically convex function
American Journal of Mathematical Analysis, 2013 1 (3),
pp 48-52.
DOI: 10.12691/ajma-1-3-5
Received November 05, 2013; Revised November 22, 2013; Accepted December 10, 2013
Copyright © 2013 Science and Education Publishing. All Rights Reserved.
1. Introduction
Let I be on interval in
. It is general knowledge that if
is a convex function and a,b∈I with a<b, then
This inequality is well known in the literature as Hermite-Hadamard’s inequality for convex functions.
In [4, 5], Niculescu defined the GA-convex and GG-convex functions as follows:
Definition 1.1. The function
is said to be geometric arithmetically convex, simply speaking, GA-convex on I if the following inequality
holds for all
and
, where
and
are respectively called the weighted geometric mean of two positive numbers
and
and the weighted arithmetic mean of
and
.
Definition 1.2. The function
is said to be geometrically convex, simply speaking, GG-convex on I if the following inequality
holds for all
and
.
For some recent results concerning Hermite-Hadamard type inequalities for GA-convex and GG-convex functions we refer interestes reader to [1, 2, 3, 6, 7].
In [2], Iscan defined the quasi-geometrically-convex functions as follows:
Definition 1.3. A function
is said to be quasi-geometrically convex on I if
For any
and
.
Clearly, any GA-convex and GG-convex functions are quasi-geometrically convex functions. Furthermore, there exist quasi-geometrically convex functions which are neither GA-convex nor GG-convex [2].
In [6], Park obtained generalized Hermite-Hadamard type integral inequalities for
-GA-convex functions by using the following lemma:
Lemma 1.1. Let
be a differentiable function on
, the interior of an interval
and
with
. If
then the following identity holds:
 | (1.1) |
for n≠0.
In [7], Zhang et al. established some Hermite-Hadamard type integral inequalities for GA-convex functions by using inequality (1.1) for
. In [3] Ji et al. established some Hermite-Hadamard type integral inequalities for
-GA-convex functions by using inequality (1.1) for
.
The goal of this article is to establish some new generalized integral inequalities of Hermite-Hadamard type for quasi-geometrically convex functions by using inequality (1.1) and Hölder inequality.
Throughout this paper we will consider
the logarithmic mean for b>a>0.
2. Hermite-Hadamard Type Inequalities for Quasi-geometrically Convex Functions
Theorem 2.1. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
, then
for
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.2. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
, then
for
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.3. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
, then
for
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.4. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.5. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.6. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.7. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
and
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.8. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
and
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.9. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
and
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.10. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
and
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
Theorem 2.11. Let
be a differentiable function on
,
with
and
. If
is quasi-geometrically convex on
for
with
, then
for
.
Proof. Since
is quasi-geometrically convex on
, from Lemma 1.1 and Hölder’s inequality we have
3. Applications to Special Means
Finally we apply Hermite-Hadamard type inequalities obtained in the above section to construct some inequalities for special means.
Proposition 3.1. For
,
and
, we have
where
and
Proof. Let
for
,
and
. Then the function
is quasi-geometrically convex function on
. Thus by the inequalities in Theorem 2.1, Theorem 2.2 and Theorem 2.3, Proposition 3.1 is proved.
Proposition 3.2. For
,
and
with
, we have
where
,
and
Proof. Let
for
,
and
. Then the function
is quasi-geometrically convex function on
. Thus by the inequalities in Theorem 2.4, Theorem 2.5, Theorem 2.6, Theorem 2.7, Theorem 2.8, Theorem 2.9, Theorem 2.10 and Theorem 2.11, Proposition 3.2 is proved.
References
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| |
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| |
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| |
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| In article | |
| |
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