Introduction
It is well known that modern investigation, directly or indirectly, involves the applications of convexity. Due to its use and significant importance, the concept of convex sets and hence convex functions is largely generalized in various directions. The concept of convexity and its variant forms have played a fundamental role in the development of different fields. Convex functions are powerful tools for proving a large class of inequalities. Today the study of convex functions evolved into a broader theory of functions including quasi-convex functions [1-3], log convex functions [4], co-ordinated convex functions [5,6], harmonically convex functions [7], GA-convex functions [8,9], (α, m) -convex functions [10]. Convexity naturally gives rise to inequalities, Hermite-Hadamard inequalities is the fisrst consequence of convex functions. A function
, where
is an interval in
is called convex, if it satisfies the inequality
where
and
.
A class of
-convex functions was introduced by Mihesan and stated as:
Definition 1 [10] A function
is called (a, m)-convex, if the inequality
holds for all
,
and
.
It is also well known that
is convex if and only if it satisfies the Hermite-Hadamard's inequality, stated below:
where
is a convex function and
with
Convexity is mixed with other mathematical concepts like; optimization [11], time scale [12,13], quantum and post quantum calculus [14].
On the other hand, several works in the field of q-analysis are being carried out, beginning with Euler, in order to achieve mastery in the mathematics that drives quantum computing. Q-calculus is the connection between physics and mathematics. It has a wide range of applications in many fields, e.g., mathematics, including number theory, combinatorics, orthogonal polynomials, basic hypergeometric functions, and other disciplines, as well as mechanics, theory of relativity, and quantum theory [15,16]. q-calculus also has many applications in quantum information theory, which is an interdisciplinary area that surrounds computer science, information theory, philosophy, and cryptography, among other areas [17, 18]. Euler is the inventor of this significant branch of mathematics. Newton used the q -parameter in his work on infinite series. The q -calculus that is known without limits calculus was presented by Jackson [19] in a systematic manner. In 1966, Al-Salam [20] introduced a q -analogue of the q -fractional integrals and q -Riemann-Liouville fractional. Since then, realted research has been increasing gently. In particular, in 2013, Tariboon and Ntouyas introduced the left quantum difference operator and left quantum integral in [21]. In 2020, Bermudo et al. introduced the notion of right quantum derivative and right quantum integral in [22].
Many integrals have also been investigated using quantum and post quantum calculus for different types of functions. For example, in [14,22-30], the authors proved Hermite-Hadamard integral inequalities and their left-right estimates for convex and co-ordinated convex functions by using the quantum derivative and integrals. In [31], the generalized version of q-integral inequalities was presented by Noor et al. In [32] Nwaeze et al. proved certain partametrized quantum integral inequalities for generalized quasi convex functions. Khan et al.proved Hermite-Hadamard inequality using the green function in [33]. For convex and co-ordinated convex functions, Budak et al. [34], Ali et al. [35,36] and Vivas-Cortez et al. [37] developed new quantum Simpson's and Newton's type inequalities.For quantum Ostrowski's type inequalities for convex and co-ordinated convex functions, please refer to [38-40].
Inspired by the ongoing studies, we derive some new inequalities of Midpoint and Trapezoid type inequalities for
-convex functions by utilizing quantum calculus. The fundamental benefit of these inequalities can be turned into quantum Midpoint and trapezoid type inequalities for convex functions [14,41], classical Midpoint for convex functions [42] and the classical Trapezoid type inequalities for convex functions [43] without having to prove each one separately.
This paper is summarized as follows: Section 2 provides a brief overview of the fundamentals of q-calculus as well as other related studies in this field. In Section 3, we establish two pivotal identities that play a major role in establishing the main outcomes of this paper. The Midpoint and Trapezoid type inequalities for q-differentiable functions via (a, m) -convexity are presented in section 4 and section 5. The special means are described in section 6. The connection between the findings reported here and similar findings in the literature are also taken into account. Section 7 concludes with some suggestions for future research.
Preliminaries and definitions of q-calculus
In this section, we first present the definitions and some properties of quantum integrals. We also mention some well known inequalities for quantum integrals. Throughout this paper, let 0<q<1 be a constant.
The q-number or q -analogue of
is given by
Jackson derived the q -Jackson integral in [44] from 0 to
as follows:
provided the sum converges absolutely.
The q Jackson integral in a generic interval
was given by in [19] and defined as follows:
Definition 2 [21] Let
be a continuous function and let
. Then the
derivative on
of
at
is defined as
Definition 3 If
in (1), then we get classical q -derivative of
at
, given by
Definition 4 [22] Let
be a continuous function and let
. Then the
derivative on
of
at
is defined as
Definition 5 [21] Let
be a continuous function. Then the
-integral on
is defined as
for
. If
in (2), then
where
is familiar q -definite integral on
defined by the expression
Moreover, if
, then the q -integral on
is defined as
Definition 6 [22] Let
be a continuous function. Then the
-integral on
is defined as
for
. If
in (3), then
where
is familiar q -definite integral on
defined by the expression
Moreover, if
, then the q -integral on
is defined as
n [14], Alp et al. proved the corresponding Hermite-Hadamard inequalities for convex functions by using
-integrals, as follows:
Theorem 1 [14] If
be a convex differentiable function on
and 0<q<1. Then,
-Hermite-Hadamard inequalities
Bermudo et al. proved the corresponding Hermite-Hadamard inequalities for convex functions by using
- integrals, as follows:
Theorem 2 [22] If
be a convex differentiable function on
and 0<q<1. Then,
-Hermite-Hadamard inequalities
From Theorem 1 and Theorem 2, one can write the following inequalities:
Corollary 1 [22] for any convex function
and 0<q<1, we have
and
Theorem 3 If
is a continious function and
, then the following identities hold:
Lemma 1 [45]For continious functions
, the following equality true:
Key Identities
In this section, we establish two quantum integral identities using the integration by parts method for quantum integrals to obtain the main outcomes.
Lemma 2 For a q-differentiable function
with
is continuous and integrable on
, the following identity holds:
Proof. From fundamental properties of quantum integrals, we have
Using the Lemma 1, we have
Similarly, we have
and
Thus from (7), (8) and (9), we have
and we obtain required equality (6) by multiplying
on both sides of (10). Thus, the proof is accomplished.
Remark 1 In Lemma 2, we have
- if we set
then we find [14, Lemma 11].
If we set
and later taking
, then we find [42, Lemma 2.1].
Lemma 3 For a q-differentiable function
with
is continious and integrable on
, the following equality holds:
Proof. From fundamental properties of quantum integral, we have
and we obtain the required equality (11) by multiplying
on both sides of (12). Thus, the proof is accomplished.
Remark 2 In Lemma 3, we have
- If we set
, then we find [41, Lemma 3.1].
If we set
and later taking limit as
, then we find [43, Lemma 2.1].
Midpoint Type inequalities for (α, m) -convex functions
Theorem 4 Under the assumption of Lemma 2, if
is
convex function over
, then we have the following midpoint type inequality:
where
Proof. By taking modulus in (6), and using (a, m) -convexity of
, we have
Thus, the proof is accomplished.
Remark 3 In Theorem 4, we have
- If we set
, then we find [14, Theorem 13].
- If we set
and later taking the limit as
, then we find [42, Theorem 2.2].
Theorem 5 Under the assumption of Lemma 2, If
is (a, m) convex function over
, then we have the following midpoint type inequality:
Proof. By taking modulus in (6), and using power mean inequality, we have
By applying (α, m)-convexity of
, we have
Thus, the proof is accomplished.
Remark 4 In Theorem 5, If we set
, then we find [14, Theorem 16].
Theorem 6 Under the assumption of Lemma 2, if r > 1 is a real number, if
is (a, m) convex function over
, then we have the following midpoint type inequality,
where
Proof. Taking absolute value of (6) and using the Hölder's inequality, we have
By applying (α, m) convexity of
, we have
Thus, the proof is accomplished.
Remark 5 In Theorem 6, we have
- If we set
, then we find [14, Theorem 18].
- If we set
and later taking the limit as
, then we find [42, Theorem 2.3].
Trapezoid type inequalities for (α, m)-convex functions
In this section, we prove Trapezoid type inequalities for differentiable (α, m) -convex functions.
Theorem 7 Under the assumption of Lemma 3, if
is (a, m) convex function over
, then we have the following trapezoid type inequality:
where
Proof. By taking modulus in (11), and using (α, m) -convexity of
, we have
Thus, the proof is accomplished.
Remark 6 In Theorem 7, we have
- If we set
, then we find [41, Theorem 4.1].
- If we set
and later taking the limit as
, then we find [43, Theorem 2.2].
Theorem 8 Under the assumption of Lemma 3, if
is (α, m) convex function over
, then we have the following trapezoid type inequality:
Proof. By taking modulus in (11) and using power mean inequality, we have
By applying (α, m)-convexity of
, we have
Thus, the proof is accomplished.
Remark 7 In Theorem 8, we have
- If we set
, then we find [41, Theorem 4.2].
- If we set
and later taking the limit as
, then we find [46, Theorem 6].
Application to special means
For any positive number
, we consider the following means:
Proposition 1 Let
and
. Then we have
where
Proof. The inequality (13) for function
leads to required result. If we take
and
in (19), we get
and
Thus,
Proposition 2 Let
and
. Then we have
where
Proof. The inequality (13) for function
leads to required result. If we take
and
in (20), we get
and
Thus,
Conclusion
In the current study, we initially proved two quantum identities using the integration by parts method. Then, using these identities, we established some new Midpoint and Trapezoid type inequalities for differentiable (α, m) -convex functions, which was the main motivation of this paper. In upcoming directions, similar inequalities could be found for co-ordinated convex functions as well.