q-Analysis and Its ApplicationsView this Special Issue
New Estimates of -Ostrowski-Type Inequalities within a Class of -Polynomial Prevexity of Functions
In this article, we develop a novel framework to study for a new class of preinvex functions depending on arbitrary nonnegative function, which is called -polynomial preinvex functions. We use the -polynomial preinvex functions to develop -analogues of the Ostrowski-type integral inequalities on coordinates. Different features and properties of excitement for quantum calculus have been examined through a systematic way. We are discussing about the suggestions and different results of the quantum inequalities of the Ostrowski-type by inferring a new identity for -differentiable function. However, the problem has been proven to utilize the obtained identity, we give -analogues of the Ostrowski-type integrals inequalities which are connected with the -polynomial preinvex functions on coordinates. Our results are the generalizations of the results in earlier papers.
Calculus is an imperative study of the derivatives and integrals. The classical derivative was convoluted with the strength regulation kind kernel, and eventually, this gave upward thrust to new calculus referred to as the quantum calculus. In mathematics, quantum calculus (named -calculus) is the study of calculus without limits. The interest in this subject has exploded, and the -calculus has in the last twenty years served as a bridge between mathematics and physics. The -calculus has numerous applications in various fields of mathematics, for example, dynamical systems, number theory, combinatorics, special functions, fractals, and also for scientific problems in some applied areas such as computer science, quantum mechanics, and quantum physics. Jackson  defined the -analogue of derivative and integral operator as well as provided some of their applications. It is imperative to mention that quantum integral inequalities are more practical and informative than their classical counterparts. It has been mainly due to the fact that quantum integral inequalities can describe the hereditary properties of the processes and phenomena under investigation. Historically, the subject of quantum calculus can be traced back to Euler and Jacobi, but in recent decades, it has experienced a rapid development. As a result, new generalizations of the classical concepts of quantum calculus have been initiated and reviewed in many literature. Tariboon and Ntouyas [2, 3] proposed the quantum calculus concepts on finite intervals and obtained several -analogues of classical mathematical objects, which inspired many other researchers to study the subject in depth, and as a consequence, numerous novel results concerning quantum analogues of classical mathematical results have been launched. Noor et al.  obtained new -analogues of inequality utilizing the first-order -differentiable convex function.
Inequality plays an irreplaceable role in the development of mathematics. Very recently, many new inequalities such as the Hermite-Hadamard-type inequality [5–9], Petrović-type inequality , Pólya-Szegö and Ćebyšev-type inequalities , Ostrowski-type inequality , reverse Minkowski inequality , Jensen-type inequality [14–16], Bessel function inequality , trigonometric and hyperbolic functions inequalities , fractional integral inequality [19–22], complete and generalized elliptic integrals inequalities [23–28], generalized convex function inequality [29–31], and mean values inequality [32–34] have been discovered by many researchers. While the concept of classical convexity has been brought into a streamline by mathematical inequalities [35–50]. In fact, convex function and its connection with mathematical inequalities have wide applications in the estimation of some parameters in scientific observations and calculations [51–65]. In recent years, the classical concept of convexity has been extended and generalized in different directions, one of the important generalization of convexity is the invexity, which was studied by Hanson ; this work has greatly expanded the role of invexity in optimization. In [67, 68], the authors introduced a class of functions, which is called preinvexity as a generalization of convex functions.
Now, we recall the classical and well-known Hermite-Hadamard inequality , which can be stated as for all if is a convex function.
Ostrowski  established an integral inequality for continuous and differentiable function as follows.
Theorem 3 (See ). Let and be continuous such that is integrable on . Then The following quantum integral version of the Hermite-Hadamard-type inequality for the coordinated convex function was proved by Alp and Sarıkaya .
Next, we present the definitions of -derivative and integral, and their two known results.
Definition 5. Let and be a continuous function. Then, the partially -derivative, -derivative, and -derivative at for the function are defined by respectively. The function is said to be partially -, -, and -differentiable on if , , and exist for all .
Definition 6. Let and be a continuous function. Then the -integral of the function on is defined by for .
Theorem 7. Let and be a continuous function. Then, we have the identities for .
Theorem 8. Let and be continuous functions. Then, the identities holds for .
Very recently, Toplu et al.  improved the Hermite-Hadamard inequality (1) by investigating the -polynomial convexity. The main purpose of the article is to introduce the notion of -polynomial preinvex function, provide a new generalized quantum integral identity, establish new quantum analogues of Ostrowski-type inequalities for the -polynomial preinvex function on coordinates, and generalize and unify the previous known results.
2. Discussions and Main Results
In the beginning of this section, we introduce the definition of -polynomial prevexity.
Definition 9 (See ). Let be a continuous bi-function. Then, is said to be invex if for all and .
Definition 10 (See ). The function is said to be preinvex if for all and .
Definition 11. Let . Then, the nonnegative function is said to be -polynomial preinvex if
for all and .
Note that if , then the definition of -polynomial preinvex function reduce to the definition of preinvex function.
If we take , then we have 2-polynomial preinvex function inequality
Proposition 12. Let and be an arbitrary family of -polynomial preinvex functions and . If is nonempty, then is an interval and is an -polynomial preinvex function on .
Proof. Let and . Then, we have This completes the proof.
In order to establish new quantum analogues of the Ostrowski-type inequalities on coordinates for the -polynomial preinvex function, we need a key lemma, which we present in this section.
Lemma 13. Let , be the interior of , and be mixed partial -differentiable on such that is continuous and integrable on for . Then, we have the identity where
Proof. Considering it follows from the definitions of partial -derivative and -integral that Note that From (20)–(23) we get Multiplying both sides of equality (25) by leads to Similarly, we have Therefore, Lemma 13 follows from (19), (27), (28), (29), and (30).
Theorem 14. Let , ,