Abstract
We use two parameters for functions whose second (q, ω)-derivatives are bounded in order to prove several recent extensions of the Ostrowski inequality and its companion inequalities on (q, ω)-Hahn difference operator. Furthermore, we procure some q-integral and continuous inequalities as special cases of the main results as well these generalizations. Symmetry plays an essential role in determining the correct methods to solve dynamic inequalities.
1. Introduction
In 1938, the following integral inequality was proved by Ostrowski [1].
Theorem 1.
Let the function be continuous on and differentiable on , then for all , we obtain
Clearly, an upper bound is estimated by inequality (1) on account of the absolute deviation between the value of at a point in and its integral mean over .
The following inequality was proved by Grüss [2] with a view to make the absolute deviation of the integral mean of the product of two functions be estimated from the product of the integral means.
Theorem 2.
Assume that Ξ and ϕ are continuous functions on such that
Then the following inequality
holds.
In the literature, inequality (2) is well known as the Grüss inequality.
The next inequality, which is known in the literature as the trapezoid inequality [3], is one of the companion inequalities of the Ostrowski inequality.
Theorem 3.
Assume that Ξ is a twice differentiable function on , then
In [4], Pachpatte procured the next trapezoid and Grüss-type inequality.
Theorem 4.
Suppose that is continuous and differentiable on , and its first derivative is bounded on , then
where .
Additionally, in the same paper [4], Pachpatte proved the following inequality.
Theorem 5.
Assume that is continuous and differentiable on , and its first derivative is bounded on , then
where .
In several fields, especially in numerical analysis, Ostrowski’s inequality has a very significant role, where we could use it in the estimation of the error in the approximation of integrals.
During the past few decades, many generalizations and amendments of the Ostrowski inequality and its associated inequalities have been done. The articles [2,3,5,6,7,8,9,10,11,12,13,14,15,16], the books [3,17] and the references cited therein are a few examples we refer to. Symmetry plays an essential role in determining the correct methods to solve dynamic inequalities.
The purpose of the present paper is as follows: first, we institute a new Ostrowski-type inequality on (q, ω)-Hahn difference operator for functions whose second (q, ω)-derivatives are bounded. Then, we confirm new generalized Trapezoid- and Grüss-type inequalities on (q, ω)-Hahn difference operator. A number of continuous and q-integral inequalities are obtained as special cases of our result.
2. Preliminaries
This section briefly introduces the calculus of Hahn-difference operators as established in [18]. Let be fixed, , and I be an interval of containing . Let Both and . The numbers play the role played by in the q-setting. In fact,
The transformation has the inverse The (q, ω)-Hahn difference operator introduced by Hahn in [19] can be defined as follows
Definition 1.
Let f be a function defined on I. The Hahn difference operator is defined by
provided that f is differentiable at In this case, we call Dq,ωf, the (q, ω)-derivative of f. We say that f is (q, ω)-differentiable, i.e., throughout I, if exists.
Note that
taking into account that mean limits from left and right at finite points, respectively. One can easily check that if are (q, ω)-differentiable at then
provided in the last identity cf. [18]. The right inverse for is defined in [18] in terms of Jackson–Nörlund sums as follows cf. [20]. Let the -integral of f from a to b is defined to be
provided that the series converges at and Here is the q-number In this case, f is called -integrable on and the sum to the right hand side of (6) will be called the Jackson–Nörlund sum—see [20] for the relationship between Nörlund sums and the difference operators. The fundamental theorem of -calculus given in [18] states that if is continuous at ,
then F is continuous at Furthermore, exists for every and
Conversely,
Consequently, the - integration by parts for continuous function is given in [18] by
Lemma 1
([18]). Let , f and g be -integrable on then for we have
Consequently, if for all then for all the inequalities
holds.
3. Main Results
3.1. An Ostrowski-Type Inequality on (q, ω)-Hahn Difference Operator
Theorem 6.
Let with τ, ν, ς, and . Further, assume that is a twice -differentiable function. Then, for all and , we get
where
and
Proof.
If we use integration by parts Formula (7), we obtain
and
Adding (11) and (12), we obtain
Similarly, we have
Substituting (14) into (13) leads to
Inequality (10) follows directly from (15) and the properties of modulus. So, the proof is completed by this. □
Corollary 1.
Tn Theorem 6, if one takes , then, inequality (10) becomes
where
and
Corollary 2.
If we take and in Theorem 6, then, inequality (10) becomes
where
and
3.2. A Trapezoid-Type Inequality on (q, ω)-Hahn Difference Operator
Theorem 7.
Under the same assumptions as in Theorem 6, we have
where
and
Proof.
From (13) we have
and similarly
Now, adding (17) and (18) produces
If we multiply the latest identity by , and by employing (7) and integrating the resulting identity with respect to from to we obtain
Equivalently
If we take the absolute value on both sides, we obtain
This shows the validity of (16). □
Corollary 3.
If we take in Theorem 7, then, inequality (16) becomes
where
and
Corollary 4.
If we take and in Theorem 7, then, inequality (16) becomes
where
and
3.3. A Grüss-Type Inequality on (q, ω)-Hahn Difference Operator
Theorem 8.
Let with τ, ν, ς, and . Moreover, assume that Ξ, are - differentiable functions. Then, for all and , we obtain
where
and
Proof.
From (13) we have
and similarly
Multiplying (20) by and (21) by , adding them and integrating the resulting identity with respect to from to yield
By using modulus properties, we obtain
The proof is terminated by this. □
Corollary 5.
If we take in Theorem 8, then, inequality (19) becomes
where
and
Corollary 6.
If we take and in Theorem 8, then, inequality (19) becomes
where
and
4. Conclusions
In this manuscript, a number of new investigations into the Ostrowski inequality and its attendant inequalities on -Hahn difference operator were discussed by using two parameters. Furthermore, definite conditions, which have not been studied before, existed in these inequalities. For instance, in Theorem 6, the second -derivative of the function is bounded, and we deal with it; however, all of the existing literature deals with functions whose first derivatives are bounded. Besides that, our inequalities were extended to be continuous and q calculus with a view to procure a number of new inequalities as special cases.
Author Contributions
Conceptualization, A.A.E.-D. and J.A.; formal analysis, A.A.E.-D. and J.A.; investigation, A.A.E.-D. and J.A.; writing–original draft preparation, A.A.E.-D. and J.A.; writing–review and editing, A.A.E.-D. and J.A. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Conflicts of Interest
The authors declare no conflict of interest.
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