1 Introduction

The Chebyshev functional is given by (see [7, 10])

$$\begin{aligned} \mathscr {T}(\mathscr {U},\mathscr {V},\mu ) =& \int _{x_{1}}^{x_{2}}\mu ( \tau )\,d\tau \int _{x_{1}}^{x_{2}} \mu (\tau )\mathscr {U}(\tau ) \mathscr {V}(\tau )\,d\tau \\ &{}- \int _{x_{1}}^{x_{2}}\mu (\tau )\mathscr {U}( \tau )\,d \tau \int _{x_{1}}^{x_{2}} \mu (\tau )\mathscr {V}(\tau )\,d \tau , \end{aligned}$$
(1)

where \(\mathscr {U}\) and \(\mathscr {V}\) are integrable functions on \([x_{1},x_{2}]\), and μ is a positive integrable function on \([x_{1},x_{2}]\). Applications of functional (1) are found in probability and statistical problems. Further applications can be found in [6, 16, 36]. In [9, 35] the authors defined the following extended Chebyshev functional:

$$\begin{aligned} \mathscr {T}(\mathscr {U},\mathscr {V}, \mu , \nu ) =& \int _{x_{1}}^{x_{2}} \nu (\tau )\,d\tau \int _{x_{1}}^{x_{2}}\mu (\tau )\mathscr {U}(\tau ) \mathscr {V}(\tau )\,d\tau \\ &{}+ \int _{x_{1}}^{x_{2}}\mu (\tau )\,d\tau \int _{x_{1}}^{x_{2}} \nu (\tau )\mathscr {U}(\tau ) \mathscr {V}(\tau )\,d\tau \\ &{}- \int _{x_{1}}^{x_{2}}\mu (\tau )\mathscr {U}(\tau )\,d \tau \int _{x_{1}}^{x_{2}} \nu (\tau )\mathscr {V}(\tau )\,d \tau \\ &{}- \int _{x_{1}}^{x_{2}}\nu (\tau ) \mathscr {U}(\tau )\,d \tau \int _{x_{1}}^{x_{2}}\mu (\tau )\mathscr {V}( \tau )\,d \tau , \end{aligned}$$
(2)

where \(\mathscr {U}\) and \(\mathscr {V}\) are integrable functions on \([x_{1},x_{2}]\), and μ and ν are positive integrable functions on \([x_{1},x_{2}]\). The functions \(\mathscr {U}\) and \(\mathscr {V}\) are said to be synchronous on \([x_{1},x_{2}]\) if

$$ \bigl(\mathscr {U}(\rho )-\mathscr {U}(\zeta ) \bigr) \bigl( \mathscr {V}(\rho )- \mathscr {V}(\zeta ) \bigr)\geq 0,\quad \rho ,\zeta \in [x_{1},x_{2}]. $$

The functions \(\mathscr {U}\) and \(\mathscr {V}\) are said to be asynchronous on \([x_{1},x_{2}]\) if the inequality reversed, that is,

$$ \bigl(\mathscr {U}(\rho )-\mathscr {U}(\zeta ) \bigr) \bigl( \mathscr {V}(\rho )- \mathscr {V}(\zeta ) \bigr)\leq 0,\quad \rho ,\zeta \in [x_{1},x_{2}]. $$

If the functions \(\mathscr {U}\) and \(\mathscr {V}\) are synchronous on \([r,s]\), then \(\mathscr {T} (\mathscr {U}, \mathscr {V},\mu )\geq 0\) and \(\mathscr {T} (\mathscr {U}, \mathscr {V}, \mu ,\nu )\geq 0\). For further details, the reader may consult Kuang [27] and Mitrinovic [35]. If we consider \(\mu (\vartheta )=\nu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), then \(\mathscr {T} (\mathscr {U}, \mathscr {V},\mu )=\frac{1}{2} \mathscr {T} (\mathscr {U}, \mathscr {V},\mu ,\nu )\). In [3, 12, 34, 44], various researchers gave valuable consideration to functionals (1) and (2). Recently, Rahman et al. [57] defined fractional conformable inequalities for the Chebyshev functionals (1) and (2).

Awan et al. [2] presented the following result: If Φ is an absolutely continuous on \([x_{1},x_{2}]\) such that \((\varPhi ^{\prime } )^{2}\in L_{1}[x_{1},x_{2}]\) and μ is a positive integrable function on \([x_{1},x_{2}]\), then the following inequality holds;

$$\begin{aligned} \mathscr {T} (\varPhi ,\varPhi ,\mu ) \leq& \frac{1}{Q^{2}(x_{2})} \int _{x_{1}}^{x_{2}} \biggl[ \int _{x_{1}}^{\tau }\mu (\tau )\,d\tau \int _{x_{1}}^{x_{2}}\tau \mu (\tau )\,d\tau - \int _{x_{1}}^{x_{2}}\mu ( \tau )\,d\tau \int _{x_{1}}^{\tau }\tau \mu (\tau )\,d\tau \biggr] \\ &{}\times\bigl[ \varPhi ^{\prime }(\theta ) \bigr]^{2}\,d\theta , \end{aligned}$$

where \(Q(x_{2})=\int _{x_{1}}^{x_{2}} \mu (\tau )\,d\tau \).

Bezziou et al. [5] presented the following result.

Theorem 1.1

Let\(\varPhi : [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function such that\((\varPhi ^{\prime } )^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\mu :[x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be an integrable function. Then we have the following inequality for\(\kappa >0\):

$$ \mathscr {J}_{x_{1}}^{\tau }\mu (x_{2}) \mathscr {J}_{x_{1}}^{\tau }\mu \varPhi ^{2}(x_{2})- \bigl(\mathscr {J}_{x_{1}}^{\tau }\mu \varPhi (x_{2}) \bigr)^{2}\leq \int _{x_{1}}^{x_{2}}\varLambda (\theta ) \bigl[\varPhi ^{\prime }(\theta ) \bigr]^{2}\,d\theta $$

with

$$ \varLambda (\theta )=\frac{1}{2} \biggl[\mathscr {J}_{x_{1}}^{\tau }x_{2} \mu (x_{2}) \int _{x_{1}}^{\tau }(x_{2}-\tau )^{\tau -1}\mu (\tau )\,d\tau -\mathscr {J}_{x_{1}}^{\tau } \mu (x_{2}) \int _{x_{1}}^{\tau }\tau (x_{2}- \tau )^{\tau -1}\mu (\tau )\,d\tau \biggr], $$

where\(\mathscr {J}_{x_{1}}^{\tau }\)is the classical RL-fractional integral.

Dahmani and Bounoua [13] established the following result.

Theorem 1.2

Let\(\varPhi : [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous such that\((\varPhi ^{\prime } )^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\mu :[x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be an integrable function. Then for all\(\kappa >0\)and\(\theta \in [x_{1},x_{2}]\), the following inequality holds;

$$\begin{aligned} &\frac{1}{\mathscr {J}_{x_{1}}^{\tau }\mu (\theta )}\mathscr {J}_{x_{1}}^{\tau } \bigl(\mu \varPhi ^{2} \bigr) (\theta )- \biggl[ \frac{1}{\mathscr {J}_{x_{1}}^{\tau }\mu (\theta )} \mathscr {J}_{x_{1}}^{\tau } (\mu \varPhi ) (\theta ) \biggr]^{2} \\ &\quad \leq \frac{1}{ [\mathscr {J}_{x_{1}}^{\tau }\mu (\theta ) ]^{2}} \int _{x_{1}}^{\theta }Q_{\theta }(\tau ) \bigl[\varPhi ^{\prime }(\tau ) \bigr]^{2}\,d\tau \end{aligned}$$

with

$$\begin{aligned} Q_{\theta }(\tau ) =&\frac{1}{\varGamma (\tau )} \biggl[\mathscr {J}_{x_{1}}^{\tau } \bigl(\theta \mu (\theta )\bigr) \int _{x_{1}}^{\rho }\mu (\vartheta ) ( \theta - \vartheta )^{\tau -1}\,d\vartheta \\ &{}-\mathscr {J}_{x_{1}}^{\kappa} \mu (\theta ) \int _{x_{1}}^{\rho }\vartheta \mu (\vartheta ) (\theta - \vartheta )^{\tau -1}\,d\vartheta \biggr], \end{aligned}$$

where\(\mathscr {J}_{x_{1}}^{\tau }\)is the classical Riemann–Liouville fractional integral.

In the last few decades, the researchers investigated different kinds of integral inequalities by considering various integral approaches. In [14] the authors gave weighted Grüss-type inequalities by taking RL-fractional integrals into account. Dahmani [8] proposed some new inequalities in the sense of fractional integrals. Several inequalities for the extended gamma function and confluent hypergeometric k-function are found by Nisar et al. [38]. Nisar et al. [39] used Riemann–Liouville and Hadamard k-fractional derivatives and investigated Gronwall-type inequalities with applications. Rahman et al. [55] studied \((k,\rho )\)-fractional integrals and investigated the corresponding inequalities. Sarikaya and Budak [59] proposed Ostrowski-type inequalities by considering local fractional integrals. Sarikaya et al. [60] proposed the idea of generalized \((k,s)\)-fractional integrals with applications. Set et al. [61] investigated Grüss-type inequalities for the generalized k-fractional integrals. Recently, Jarad et al. [22, 23] proposed the idea of fractional conformable and proportional fractional integral operators. Huang et al. [20] recently presented generalized Hermite–Hadamard-type inequalities for k-fractional conformable integrals. Qi et al. [45] proposed Chebyshev-type inequalities by using generalized k-fractional conformable integrals. Rahman et al. [56] investigated Chebyshev-type inequalities by utilizing fractional conformable integrals. Chebyshev-type inequalities and Minkowski-type inequalities involving generalized conformable integrals can be found in the work of Nisar et al. [42, 43]. Recently, Tassaddiq et al. [63] proposed certain inequalities for the weighted and extended Chebyshev functionals by using fractional conformable integrals. Nisar et al. [40] presented some new classes of inequalities for an n (\(n\in \mathbb{N}\)) family of positive continuous and decreasing functions via generalized conformable fractional integrals. Nisar et al. [41] established generalized fractional integral inequalities via the Marichev–Saigo–Maeda (MSM) fractional integral operators. Rahman et al. [54] recently investigated Grüss-type inequalities for generalized k-fractional conformable integrals. Minkowski’s inequalities, fractional Hadamard proportional integral inequalities, and fractional proportional inequalities for convex functions by employing fractional proportional integrals can be found in [4653]. In addition, various applications of fractional calculus can be found in [1, 17, 18, 2832, 62, 64].

The paper is organized as follows. Some auxiliary results are presented in Sect. 2. In Sect. 3, we present double-weighted fractional integral inequalities for the Chebyshev functionals. In Sect. 4, we retrieve several particular cases of the results. A concluding remark is given in Sect. 5.

2 Auxiliary results

In this section, we present some well-known definitions and mathematical preliminaries of fractional calculus.

Definition 2.1

([26, 58])

Let \(\mathscr {U}\in L[x_{1},x_{2}]\). Then the classical left- and right-sided RL-fractional integrals of order \(\tau >0\) and \(x_{1}\geq 0\) are respectively defined by

$$ \bigl({}_{x_{1}}\mathscr {J}^{\tau }\mathscr {U} \bigr) (\vartheta )= \frac{1}{\varGamma (\tau )} \int _{a}^{\vartheta }(\vartheta -\varrho )^{ \tau -1}\mathscr {U}(\varrho )\,d\varrho ,\quad x_{1}< \vartheta , $$
(3)

and

$$ \bigl(\mathscr {J}_{x_{2}}^{\tau }\mathscr {U} \bigr) (\vartheta )= \frac{1}{\varGamma (\tau )} \int _{\vartheta }^{x_{2}} (\varrho -\vartheta )^{ \tau -1}\mathscr {U}(\varrho )\,d\varrho , \quad \vartheta < x_{2}, $$
(4)

where Γ is the standard gamma function.

Definition 2.2

([37])

Let \(\mathscr {U}\in L[x_{1},x_{2}]\). Then the generalized left- and right-sided RL κ-fractional integrals of order \(\tau >0\) and \(x_{1}\geq 0\) are respectively defined by

$$ \bigl({}_{x_{1}}\mathscr {J}_{\kappa }^{\tau } \mathscr {U} \bigr) ( \vartheta )=\frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{a}^{\vartheta }(\vartheta -\varrho )^{\frac{\tau }{\kappa }-1}\mathscr {U}( \varrho )\,d\varrho , \quad x_{1}< \vartheta , $$
(5)

and

$$ \bigl(\mathscr {J}_{x_{2}, \kappa }^{\tau }\mathscr {U} \bigr) ( \vartheta )=\frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{\vartheta }^{x_{2}} (\varrho -\vartheta )^{\frac{\tau }{\kappa }-1}\mathscr {U}(\varrho )\,d\varrho , \quad \vartheta < x_{2}, $$
(6)

where \(\varGamma _{\kappa }\) is the κ-gamma function defined in [15].

Remark 2.1

Applying Definition 2.2 for \(\kappa =1\), we get Definition 2.1.

Definition 2.3

([26])

Let \(\mathscr {U}:[x_{1},x_{2}]\rightarrow \mathbb{R}\) be an integrable function, and let Ψ be an increasing positive function on \((x_{1},x_{2}]\) with continuous derivative \(\varPsi ^{\prime }\) on \((x_{1},x_{2})\). Then the left- and right-sided generalized RL fractional integrals of a function \(\mathscr {U}\) concerning another function Ψ are respectively defined by

$$ \bigl({}_{x_{1}}^{\varPsi }\mathscr {J}^{\tau } \mathscr {U} \bigr) (\rho ) = \frac{1}{\varGamma (\tau )} \int _{x_{1}}^{\vartheta } \bigl(\varPsi ( \vartheta )- \varPsi ( \varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\mathscr {U(\varrho )}\,d\varrho ,\quad x_{1}< \vartheta , $$
(7)

and

$$ \bigl({}^{\varPsi }\mathscr {J}_{x_{2}}^{\tau } \mathscr {U} \bigr) (\rho ) = \frac{1}{\varGamma (\tau )} \int _{\vartheta }^{x_{2}} \bigl(\varPsi ( \varrho )- \varPsi ( \vartheta ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\mathscr {U( \varrho )}\,d\varrho ,\quad \vartheta < x_{2}, $$
(8)

where \(\kappa >0\) and \(\tau \in \mathbb{C}\) with \(\Re (\tau )>0\).

Definition 2.4

([33])

Let \(\mathscr {U}:[x_{1},x_{2}]\rightarrow \mathbb{R}\) be an integrable function, and let Ψ be an increasing positive function on \((x_{1},x_{2}]\) with continuous derivative \(\varPsi ^{\prime }\) on \((x_{1},x_{2})\). Then the left- and right-sided generalized RL κ-fractional integrals of a function \(\mathscr {U}\) concerning another function Ψ are respectively defined by

$$ \bigl({}_{x_{1}}^{\varPsi }\mathscr {J}_{\kappa }^{\tau } \mathscr {U} \bigr) ( \rho ) =\frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (\vartheta )- \varPsi ( \varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\mathscr {U(\varrho )}\,d\varrho ,\quad x_{1}< \vartheta , $$
(9)

and

$$ \bigl({}^{\varPsi }\mathscr {J}_{x_{2},\kappa }^{\tau } \mathscr {U} \bigr) ( \rho ) =\frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{\vartheta }^{x_{2}} \bigl(\varPsi (\varrho )- \varPsi ( \vartheta ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\mathscr {U( \varrho )}\,d\varrho ,\quad \vartheta < x_{2}, $$
(10)

where \(\kappa >0\) and \(\tau \in \mathbb{C}\) with \(\Re (\tau )>0\).

Remark 2.2

The following particular cases are easily derived:

  1. i.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\vartheta \), we get Definition 2.2,

  2. ii.

    Applying Definition 2.4 for \(\kappa =1\), we get Definition 2.3,

  3. iii.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\ln \vartheta \), we get the generalized Hadamard κ-fractional integrals defined in [21],

  4. iv.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\ln \vartheta \) and \(\kappa =1\) leads to the Hadamard fractional integrals defined in [26],

  5. v.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\frac{\vartheta ^{\tau }}{\tau }\), \(\tau >0\), and \(\kappa =1\) leads to the Katugampola fractional integrals [24],

  6. vi.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\frac{\vartheta ^{\alpha +s}}{\alpha +s}\) and \(\kappa =1\) (where \(\alpha \in (0,1]\), \(s\in \mathbb{R}\), and \(\mu +s\neq 0\)) leads to the generalized fractional conformable integrals defined by Khan and Khan [25],

  7. vii.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\frac{(\vartheta -x_{1})^{\alpha }}{\alpha }\) and \(\varPsi (\vartheta )=\frac{-(x_{2}-\vartheta )^{\alpha }}{\alpha }\), \(\alpha >0\), leads to the \((k,\alpha )\)-fractional conformable integrals defined by Habib et al. [19].

  8. viii.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\frac{(\vartheta -x_{1})^{\alpha }}{\alpha }\), \(\varPsi (\vartheta )=\frac{-(x_{2}-\vartheta )^{\alpha }}{\alpha }\), \(\alpha >0\), and \(\kappa =1\) leads to the conformable fractional integrals defined by Jarad et al. [23],

  9. ix.

    Applying Definition 2.4 for \(\varPsi (\vartheta )=\vartheta \) and \(\kappa =1\), we get Definition 2.1.

3 Some double-weighted generalized fractional integral inequalities

In this section, we present some double-weighted generalized fractional integral inequalities. We start by proving the following lemma.

Lemma 3.1

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(\mathscr {V}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be continuous on\([x_{1},x_{2}]\), and let\(\mu ,\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \nu \mathscr {V}) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mathscr {V}(x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \mu \mathscr {V}) (x_{2}) \bigr] \\& \qquad {}- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2})x_{2} \mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu \mathscr {V}) (x_{2}) \bigr]- \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\nu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu \mathscr {V}) (x_{2}) \bigr] \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \bigl(\varPsi ^{\prime }(\vartheta ) \bigr)\,d\vartheta . \end{aligned}$$
(11)

Proof

Suppose that \(\mathscr {U}: [x_{1},x_{2}]\rightarrow \mathbb{R}\) is a continuous function on \([x_{1},x_{2}]\). Then we get

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \mathscr {U} \mathscr {V}) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mathscr {V}(x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \mathscr {U}\mathscr {V}) (x_{2}) \bigr] \\& \qquad {}- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \mathscr {U}) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \mathscr {V}) (x_{2}) \bigr]- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu \mathscr {U}) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu \mathscr {V}) (x_{2}) \bigr] \\& \quad = \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) \bigl[ \bigl(\mathscr {U}(\xi )-\mathscr {U}( \varrho ) \bigr) \bigl(\mathscr {V}( \xi )-\mathscr {V}(\varrho ) \bigr) \bigr]\,d\xi \,d\varrho . \end{aligned}$$

Consequently, it follows that

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu \mathscr {U} \mathscr {V}) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mathscr {V}(x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \mathscr {U}\mathscr {V}) (x_{2}) \bigr] \\& \qquad {}- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \mathscr {U}) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \mathscr {V}) (x_{2}) \bigr]- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu \mathscr {U}) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu \mathscr {V}) (x_{2}) \bigr] \\& \quad = \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) \bigl(\mathscr {U}(\xi )-\mathscr {U}(\varrho ) \bigr) \biggl( \int _{\varrho }^{\xi }\mathscr {V}^{\prime }( \vartheta )\,d\vartheta \biggr)\,d\xi \,d\varrho . \end{aligned}$$
(12)

Utilizing the condition \(x_{1}\leq \varrho \leq \vartheta \leq \xi \leq x_{2}\), we conclude that

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu \mathscr {U} \mathscr {V}) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mathscr {V}(x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \mathscr {U}\mathscr {V}) (x_{2}) \bigr] \\& \qquad {}- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \mathscr {U}) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \mathscr {V}) (x_{2}) \bigr]- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu \mathscr {U}) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu \mathscr {V}) (x_{2}) \bigr] \\& \quad = \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \biggl[ \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho ) \\& \qquad {}\times \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\mathscr {U}(\xi )-\mathscr {U}(\varrho ) \bigr) \varPsi ^{\prime }(\xi )\mu (\xi ) \,d\xi \,d\varrho \biggr] \bigl( \mathscr {V}^{\prime }(\vartheta ) \bigr)\,d\vartheta . \end{aligned}$$
(13)

Applying (13) to the particular case \(\mathscr {U}(x)=x\), we can write

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}(\nu \mathscr {V}) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mathscr {V}(x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \mu \mathscr {V}) (x_{2}) \bigr] \\& \qquad {}- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \mu ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \mathscr {V}) (x_{2}) \bigr]- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \nu ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu \mathscr {V}) (x_{2}) \bigr] \\& \quad = \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \biggl[ \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho ) \\& \qquad {}\times \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} (\xi -\varrho ) \varPsi ^{\prime }(\xi ) \mu (\xi ) \,d\xi \,d\varrho \biggr] \bigl(\mathscr {V}^{\prime }(\vartheta ) \bigr)\,d\vartheta \\& \quad = \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[ \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \bigl( \varPsi (x_{2})- \varPsi (\xi ) \bigr)^{\frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\xi \mu (\xi ) \,d \xi \\& \qquad {}\times \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho -\frac{1}{\kappa \varGamma _{\kappa }(\tau )} \\& \qquad {}\times \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \,d\xi \times \int _{x_{1}}^{\vartheta } \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\varrho )\varrho \nu (\varrho )\,d\varrho \biggr] \bigl( \mathscr {V}^{\prime }(\vartheta ) \bigr)\,d\vartheta . \end{aligned}$$

The latter by (9) gives

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}(\nu \mathscr {V}) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mathscr {V}(x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \mu \mathscr {V}) (x_{2}) \bigr] \\& \qquad {}- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \mu ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \mathscr {V}) (x_{2}) \bigr]- \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2}( \nu ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu \mathscr {V}) (x_{2}) \bigr] \\& \quad = \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[ {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{ \vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho ) \nu (\varrho )\,d\varrho \biggr] \bigl(\mathscr {V}^{\prime }( \vartheta ) \bigr)\,d\vartheta , \end{aligned}$$

which completes the proof. □

Based on Lemma 3.1, we prove the following theorem.

Theorem 3.1

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(\varPhi : [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((\varPhi ^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\mu ,\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable functions. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \bigl(\nu \varPhi ^{2}\bigr) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\bigl(\mu \varPhi ^{2}\bigr) (x_{2}) \bigr] \\& \qquad {}- 2 \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \varPhi ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \varPhi ) (x_{2}) \bigr] \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \bigl(\varPhi ^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta . \end{aligned}$$
(14)

Proof

By employing definition (9) and Lemma 3.1 we obtain

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\bigl(\nu \varPhi ^{2}\bigr) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \bigl(\mu \varPhi ^{2}\bigr) (x_{2}) \bigr] \\& \qquad {}- 2 \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \varPhi ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \varPhi ) (x_{2}) \bigr] \\& \quad = \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) \bigl(\varPhi (\xi )-\varPhi (\varrho ) \bigr)^{2}\,d\xi \,d\varrho \\& \quad = \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) (\xi -\varrho )^{2} \biggl( \frac{\varPhi (\xi )-\varPhi (\varrho )}{\xi -\varrho } \biggr)^{2}\,d\xi \,d\varrho . \end{aligned}$$

Consequently, it follows that

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\bigl(\nu \varPhi ^{2}\bigr) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \bigl(\mu \varPhi ^{2}\bigr) (x_{2}) \bigr] \\& \qquad {}- 2 \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \varPhi ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \varPhi ) (x_{2}) \bigr] \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) (\xi -\varrho )^{2} \biggl( \frac{\int _{\varrho }^{\xi }\varPhi ^{\prime }(\vartheta )\,d\vartheta }{\xi -\varrho } \biggr)^{2}\,d\xi \,d\varrho . \end{aligned}$$

By the Cauchy–Schwarz inequality [11] we get

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \bigl(\nu \varPhi ^{2}\bigr) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\bigl(\mu \varPhi ^{2}\bigr) (x_{2}) \bigr] \\& \qquad {}- 2 \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \varPhi ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \varPhi ) (x_{2}) \bigr] \\& \quad = \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) (\xi -\varrho )^{2} \biggl( \frac{\int _{\varrho }^{\xi }\varPhi ^{\prime }(\vartheta )\,d\vartheta }{\xi -\varrho } \biggr)^{2}\,d\xi \,d\varrho \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) (\xi -\varrho )^{2} \biggl( \frac{ (\int _{\varrho }^{\xi }\,d\vartheta )^{\frac{1}{2}} (\int _{\varrho }^{\xi } (\varPhi ^{\prime }(\vartheta ) )^{2}\,d\vartheta )^{\frac{1}{2}}}{\xi -\varrho } \biggr)^{2}\,d\xi \,d\varrho \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) (\xi -\varrho )^{2} \biggl( \frac{ (\int _{\varrho }^{\xi } (\varPhi ^{\prime }(\vartheta ) )^{2}\,d\vartheta )}{\xi -\varrho } \biggr)\,d\xi \,d \varrho \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) (\xi -\varrho ) \biggl( \int _{\varrho }^{\xi } \bigl(\varPhi ^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)\,d\xi \,d\varrho . \end{aligned}$$
(15)

Hence using (13) and (15), we conclude the proof. □

Corollary 3.1

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(\varPhi : [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((\varPhi ^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl[ \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \biggr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\bigl(\nu \varPhi ^{2}\bigr) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \bigl(\varPhi ^{2}\bigr) (x_{2}) \bigr] \\& \qquad {}- 2 \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \varPhi ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu \varPhi ) (x_{2}) \bigr] \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \bigl(\varPhi ^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta . \end{aligned}$$

Proof

By considering \(\mu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), in Theorem 3.1 we obtain the desired result. □

Corollary 3.2

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(\varPhi : [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((\varPhi ^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\mu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\bigl(\varPhi ^{2}\bigr) (x_{2}) \bigr]+ \biggl[ \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \biggr] \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \bigl(\varPhi ^{2}\bigr) (x_{2}) \bigr] \\& \qquad {}- 2 \bigl[{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu \varPhi ) (x_{2}) \bigr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\varPhi ) (x_{2}) \bigr] \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \biggr] \bigl( \varPhi ^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta . \end{aligned}$$

Proof

By considering \(\nu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), in Theorem 3.1 we get the desired result. □

Corollary 3.3

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(\varPhi : [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((\varPhi ^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\). Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl[ \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \biggr] \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\bigl(\varPhi ^{2}\bigr) (x_{2}) \bigr] - \bigl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\varPhi ) (x_{2}) \bigr]^{2} \\& \quad \leq \frac{1}{2\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \biggr] \bigl(\varPhi ^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta . \end{aligned}$$

Proof

Taking \(\mu (\vartheta )=\nu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), in Theorem 3.1, we obtain the desired result. □

Theorem 3.2

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions with\((f_{1}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\)and\((f_{2}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\mu ,\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl\vert {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \bigl(f_{1}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}} \\& \qquad {}\times \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho ) \nu ( \varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \bigl(f_{2}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}}. \end{aligned}$$
(16)

Proof

Considering the left-hand side of (16), we have

$$\begin{aligned}& \bigl\vert {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl( \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \\& \qquad {}\times \varPsi ^{\prime }(\varrho )\nu (\varrho ) \bigl(f_{1}( \xi )-f_{1}( \varrho ) \bigr)^{2} \,d\xi \,d\varrho \biggr)^{\frac{1}{2}}\times \biggl( \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi ( \xi ) \bigr)^{\frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \varPsi ^{\prime }( \varrho )\nu (\varrho ) \bigl(f_{2}(\xi )-f_{2}(\varrho ) \bigr)^{2} \,d\xi \,d\varrho \biggr)^{\frac{1}{2}} \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl( \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \\& \qquad {}\times \varPsi ^{\prime }(\varrho )\nu (\varrho ) \biggl( \int _{\varrho }^{\xi }f_{1}^{\prime }( \vartheta )\,d\vartheta \biggr)^{2} \,d\xi \,d\varrho \biggr)^{\frac{1}{2}}\times \biggl( \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{\frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \varPsi ^{\prime }( \varrho )\nu (\varrho ) \biggl( \int _{\varrho }^{\xi }f_{2}^{\prime }( \vartheta )\,d\vartheta \biggr)^{2} \,d\xi \,d\varrho \biggr)^{\frac{1}{2}}. \end{aligned}$$

Applying the Cauchy–Schwarz inequality [11] to this inequality, we get

$$\begin{aligned}& \bigl\vert {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl[ \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \\& \qquad {}\times \varPsi ^{\prime }(\varrho )\nu (\varrho ) \biggl( \biggl( \int _{\varrho }^{\xi }\,d\vartheta \biggr)^{\frac{1}{2}} \biggl( \int _{\varrho }^{\xi } \bigl(f_{1}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}} \biggr)^{2} \,d\xi \,d\varrho \biggr]^{\frac{1}{2}} \\& \qquad {}\times \biggl[ \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi ( \xi ) \bigr)^{\frac{\tau }{\kappa }-1}\bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \\& \qquad {}\times \varPsi ^{\prime }(\xi )\mu (\xi ) \varPsi ^{\prime }( \varrho )\nu (\varrho ) \biggl( \biggl( \int _{\varrho }^{\xi }\,d\vartheta \biggr)^{\frac{1}{2}} \biggl( \int _{\varrho }^{\xi } \bigl(f_{2}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}} \biggr)^{2} \,d\xi \,d\varrho \biggr]^{\frac{1}{2}} \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl[ \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \\& \qquad {}\times \varPsi ^{\prime }(\varrho )\nu (\varrho ) (\xi -\varrho ) \biggl( \int _{\varrho }^{\xi } \bigl(f_{1}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr) \,d\xi \,d\varrho \biggr]^{\frac{1}{2}} \times \biggl[ \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{\frac{\tau }{\kappa }-1} \\& \qquad {}\times \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\xi )\mu (\xi ) \varPsi ^{\prime }( \varrho )\nu (\varrho ) (\xi -\varrho ) \biggl( \int _{\varrho }^{\xi } \bigl(f_{2}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr) \,d\xi \,d\varrho \biggr]^{\frac{1}{2}} \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl[ \int _{x_{1}}^{x_{2}} \biggl( \int _{x_{1}}^{x_{2}} \xi \bigl(\varPsi (x_{2})-\varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi )\,d\xi \\& \qquad {}\times \int _{x_{1}}^{ \vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \biggr) \bigl(f_{1}^{\prime }(\vartheta ) \bigr)^{2} \biggr]^{\frac{1}{2}} \\& \qquad {}- \biggl[ \int _{x_{1}}^{x_{2}} \biggl( \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu ( \xi )\,d\xi \\& \qquad {}\times \int _{x_{1}}^{\varrho }\varrho \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho ) \nu (\varrho )\,d\varrho \biggr) \bigl(f_{2}^{\prime }( \vartheta ) \bigr)^{2} \biggr]^{\frac{1}{2}}. \end{aligned}$$

In view of (9), we get the desired proof of (16). □

Corollary 3.4

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions with\((f_{1}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\)and\((f_{2}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }(f_{1}) (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \bigl(f_{1}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}} \\& \qquad {}\times \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi ( \varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu ( \varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \bigl(f_{2}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}}. \end{aligned}$$

Proof

Applying Theorem 3.2 with \(\mu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), we obtain the desired result. □

Corollary 3.5

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions with\((f_{1}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\)and\((f_{2}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\mu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}f_{2}) (x_{2})+ \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }(f_{1}) (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \biggr] \bigl(f_{1}^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}} \\& \qquad {}\times \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \biggr] \bigl(f_{2}^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}}. \end{aligned}$$

Proof

Applying Theorem 3.2 with \(\nu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), we obtain the desired result. □

Corollary 3.6

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions with\((f_{1}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\)and\((f_{2}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\), and let\(\mu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{1}f_{2}) (x_{2}) -{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }(f_{1}) (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{1}) (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{1}{2\kappa \varGamma _{\kappa }(\tau )} \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \biggr] \bigl(f_{1}^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}} \\& \qquad {}\times \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi ( \varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \biggr] \bigl(f_{2}^{\prime }(\vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}}. \end{aligned}$$

Proof

Applying Theorem 3.2 with \(\mu (\vartheta )=\nu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), we obtain the desired result. □

Theorem 3.3

LetΨbe measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((f_{1}^{\prime })\in L^{\infty }[x_{1},x_{2}]\), and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be nondecreasing. Moreover, let\(\mu ,\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)be positive integrable, Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl\vert {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty }}{\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \int _{x_{1}}^{x_{2}}f_{2}^{\prime }( \vartheta )\,d\vartheta . \end{aligned}$$
(17)

Proof

Considering the left-hand side of (17), we have

$$\begin{aligned}& \bigl\vert {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl\vert \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) \\& \qquad {}\times \bigl[ \bigl(f_{1}(\xi )-f_{1}(\varrho ) \bigr) \bigl(f_{2}( \xi )-f_{2}(\varrho ) \bigr) \bigr]\,d \xi \,d\varrho \biggr\vert \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) \\& \qquad {}\times \biggl\vert \frac{ (f_{1}(\xi )-f_{1}(\varrho ) )}{\xi -\varrho } \biggr\vert {} \bigl\vert (\xi -\varrho ) \bigl(f_{2}(\xi )-f_{2}(\varrho ) \bigr) \bigr\vert \,d\xi \,d\varrho \\& \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty }}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{\frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi ( \varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi ) \varPsi ^{\prime }(\varrho )\nu (\varrho ) \\& \qquad {}\times (\xi -\varrho ) \biggl( \int _{x_{1}}^{x_{2}} f_{2}^{\prime }( \vartheta )\,d\vartheta \biggr)\,d\xi \,d\varrho \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty }}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl[ \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\xi \varPsi ^{\prime }(\xi )\mu (\xi )\,d\xi \\& \qquad {}\times\int _{x_{1}}^{ \vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\varrho )\nu ( \varrho )\,d\varrho - \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi )\,d\xi \\& \qquad {}\times\int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \biggr] \int _{x_{1}}^{x_{2}} f_{2}^{\prime }( \vartheta )\,d\vartheta. \end{aligned}$$

Hence taking (9) into account, we complete the proof of (17). □

Corollary 3.7

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((f_{1}^{\prime })\in L^{\infty }[x_{1},x_{2}]\), and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be a nondecreasing function. Suppose that\(\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)is positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty }}{\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \int _{x_{1}}^{x_{2}}f_{2}^{\prime }( \vartheta )\,d\vartheta . \end{aligned}$$

Proof

Applying Theorem 3.3 with \(\mu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), we obtain the desired result. □

Corollary 3.8

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((f_{1}^{\prime })\in L^{\infty }[x_{1},x_{2}]\), and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be nondecreasing. Suppose that\(\mu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)is positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}f_{2}) (x_{2})+ {} \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty }}{\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \biggr] \int _{x_{1}}^{x_{2}}f_{2}^{\prime }( \vartheta )\,d\vartheta . \end{aligned}$$

Proof

Applying Theorem 3.3 with \(\nu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), we obtain the desired result. □

Corollary 3.9

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be an absolutely continuous function with\((f_{1}^{\prime })\in L^{\infty }[x_{1},x_{2}]\), and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be nondecreasing. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{1}f_{2}) (x_{2}) -{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty }}{2\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \biggr] \int _{x_{1}}^{x_{2}}f_{2}^{\prime }( \vartheta )\,d\vartheta . \end{aligned}$$

Proof

Applying Theorem 3.3 with \(\mu (\vartheta )=\nu (\vartheta )=1\), \(\vartheta \in [x_{1},x_{2}]\), we obtain the desired result. □

Theorem 3.4

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions, and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be nondecreasing. Suppose that\(\mu ,\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)are positive integrable. If\(f_{1}^{\prime }, f_{2}^{\prime }\in L^{\infty }[x_{1},x_{2}]\), then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl\vert {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\mu (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty } \Vert f_{2}^{\prime } \Vert _{\infty }}{\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}^{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- 2{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2} \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \\& \qquad {}+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho ^{2} \bigl( \varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \biggr]. \end{aligned}$$
(18)

Proof

Considering the left-hand side of (18), we have

$$\begin{aligned}& \bigl\vert {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl\vert \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) \\& \qquad {}\times \bigl[ \bigl(f_{1}(\xi )-f_{1}(\varrho ) \bigr) \bigl(f_{2}( \xi )-f_{2}(\varrho ) \bigr) \bigr]\,d \xi \,d\varrho \biggr\vert \\& \quad \leq \frac{1}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi )\varPsi ^{\prime }( \varrho )\nu (\varrho ) \\& \qquad {}\times \biggl\vert \frac{ (f_{1}(\xi )-f_{1}(\varrho ) )}{\xi -\varrho } \biggr\vert {} \biggl\vert \frac{ (f_{2}(\xi )-f_{2}(\varrho ) )}{\xi -\varrho } \biggr\vert ( \xi -\varrho )^{2}\,d\xi \,d \varrho \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty } \Vert f_{2}^{\prime } \Vert _{\infty }}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \int _{x_{1}}^{x_{2}} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{\frac{\tau }{\kappa }-1} \bigl(\varPsi (x_{2})-\varPsi ( \varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi ) \varPsi ^{\prime }(\varrho )\nu (\varrho ) \\& \qquad {}\times \bigl(\xi ^{2} -2\xi \varrho +\varrho ^{2} \bigr)\,d\xi \,d\varrho \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty } \Vert f_{2}^{\prime } \Vert _{\infty }}{\kappa ^{2}\varGamma _{\kappa }^{2}(\tau )} \biggl[ \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\xi ^{2}\varPsi ^{\prime }(\xi ) \mu (\xi )\,d\xi \\& \qquad {}\times\int _{x_{1}}^{ \vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\varrho )\nu ( \varrho )\,d\varrho \\& \qquad {}- 2 \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\xi \varPsi ^{\prime }(\xi )\mu (\xi )\,d\xi \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}+ \int _{x_{1}}^{x_{2}} \bigl(\varPsi (x_{2})- \varPsi (\xi ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\xi )\mu (\xi )\,d\xi \int _{x_{1}}^{ \vartheta }\varrho ^{2} \bigl( \varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1} \varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \biggr]. \end{aligned}$$

Hence by (9) we complete the proof. □

Corollary 3.10

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions, and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be nondecreasing. Suppose that\(\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)is positive integrable. If\(f_{1}^{\prime }, f_{2}^{\prime }\in L^{\infty }[x_{1},x_{2}]\), then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \nu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \nu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\nu f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty } \Vert f_{2}^{\prime } \Vert _{\infty }}{\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}^{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu (\varrho )\,d\varrho \\& \qquad {}- 2{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\nu (\varrho )\,d\varrho \\& \qquad {}+ \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} \int _{x_{1}}^{\vartheta }\varrho ^{2} \bigl( \varPsi (x_{2})-\varPsi ( \varrho ) \bigr)^{\frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\nu ( \varrho )\,d\varrho \biggr]. \end{aligned}$$

Proof

Setting \(\mu (\vartheta )=1\), \(\vartheta \in [x_{1}, x_{2}]\), in Theorem 3.4, we obtain the desired result. □

Corollary 3.11

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions, and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be nondecreasing. Suppose that\(\mu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)is positive integrable. If\(f_{1}^{\prime }, f_{2}^{\prime }\in L^{\infty }[x_{1},x_{2}]\), then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}f_{2}) (x_{2})+ {} \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }(\mu f_{2}) (x_{2})- {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( \mu f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty } \Vert f_{2}^{\prime } \Vert _{\infty }}{\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}^{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- 2{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2} \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \\& \qquad {}+ {}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho ^{2} \bigl( \varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \biggr]. \end{aligned}$$

Proof

Setting \(\nu (\vartheta )=1\), \(\vartheta \in [x_{1}, x_{2}]\), in Theorem 3.4, we obtain the desired result. □

Corollary 3.12

LetΨbe a measurable increasing positive function on\((x_{1},x_{2})\)with continuous derivative\(\varPsi ^{\prime }(\varrho )\)on\([x_{1},x_{2}]\). Let\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be absolutely continuous functions, and let\(f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)be nondecreasing. If\(f_{1}^{\prime }, f_{2}^{\prime }\in L^{\infty }[x_{1},x_{2}]\), then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \biggl\vert \frac{ (\varPsi (x_{2})-\varPsi (x_{1}) )^{\frac{\tau }{\kappa }}}{\varGamma _{\kappa }(\tau +\kappa )} {}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{1}f_{2}) (x_{2}) -{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }( f_{1}) (x_{2}){}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }( f_{2}) (x_{2}) \biggr\vert \\& \quad \leq \frac{ \Vert f_{1}^{\prime } \Vert _{\infty } \Vert f_{2}^{\prime } \Vert _{\infty }}{2\kappa \varGamma _{\kappa }(\tau )} \biggl[{}_{x_{1}}^{\varPsi } \mathscr {I}_{\kappa }^{\tau }x_{2}^{2} \int _{x_{1}}^{\vartheta } \bigl(\varPsi (x_{2})- \varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \\& \qquad {}- 2{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau }x_{2} \int _{x_{1}}^{ \vartheta }\varrho \bigl(\varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }( \varrho )\,d\varrho \\& \qquad {}+{}_{x_{1}}^{\varPsi }\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}) \int _{x_{1}}^{\vartheta } \varrho ^{2} \bigl( \varPsi (x_{2})-\varPsi (\varrho ) \bigr)^{ \frac{\tau }{\kappa }-1}\varPsi ^{\prime }(\varrho )\,d\varrho \biggr]. \end{aligned}$$

Proof

Setting \(\mu (\vartheta )=\nu (\vartheta )=1\), \(\vartheta \in [x_{1}, x_{2}]\), in Theorem 3.4, we obtain the desired result. □

4 Particular cases

Here we present some inequalities in terms of the Riemann–Liouville κ-fractional integrals, which are the particular cases of the main results.

Theorem 4.1

Suppose that\(\varPhi : [x_{1},x_{2}]\rightarrow \mathbb{R}\)is absolutely continuous on\([x_{1},x_{2}]\)with\((\varPhi ^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\)and that\(\mu ,\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)are positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl[{}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \bigr] \bigl[ {}_{x_{1}}\mathscr {I}_{\kappa }^{\tau } \bigl(\nu \varPhi ^{2}\bigr) (x_{2}) \bigr]+ \bigl[{}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }\nu (x_{2}) \bigr] \bigl[ {}_{x_{1}}\mathscr {I}_{\kappa }^{\tau } \bigl(\mu \varPhi ^{2}\bigr) (x_{2}) \bigr] \\& \qquad {}- 2 \bigl[{}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }(\mu \varPhi ) (x_{2}) \bigr] \bigl[{}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }( \nu \varPhi ) (x_{2}) \bigr] \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}} \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } (x_{2}-\varrho )^{\frac{\tau }{\kappa }-1}\nu ( \varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho (x_{2}-\varrho )^{\frac{\tau }{\kappa }-1} \nu (\varrho )\,d\varrho \biggr] \bigl(\varPhi ^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta . \end{aligned}$$

Proof

Applying Theorem 3.1 with \(\varPsi (\vartheta )=\vartheta \) gives the proof of the theorem. □

Theorem 4.2

Suppose that\(f_{1}, f_{2}: [x_{1},x_{2}]\rightarrow \mathbb{R}\)are absolutely continuous functions with\((f_{1}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\)and\((f_{2}^{\prime })^{2}\in L_{1}[x_{1},x_{2}]\)and that\(\mu ,\nu : [x_{1},x_{2}]\rightarrow \mathbb{R}^{+}\)are positive integrable. Then for all\(\tau ,\kappa >0\), we have

$$\begin{aligned}& \bigl\vert {}_{x_{1}}\mathscr {I}_{\kappa }^{\tau } \mu (x_{2}){}_{x_{1}} \mathscr {I}_{\kappa }^{\tau }( \nu f_{1}f_{2}) (x_{2})+ {}_{x_{1}} \mathscr {I}_{\kappa }^{\tau }\nu (x_{2}){}_{x_{1}} \mathscr {I}_{\kappa }^{ \tau }(\mu f_{1}f_{2}) (x_{2}) \\& \qquad {}- {}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }(\nu f_{1}) (x_{2}){}_{x_{1}} \mathscr {I}_{\kappa }^{\tau }( \mu f_{2}) (x_{2})- {}_{x_{1}} \mathscr {I}_{\kappa }^{\tau }(\mu f_{1}) (x_{2}){}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }( \nu f_{2}) (x_{2}) \bigr\vert \\& \quad \leq \frac{1}{\kappa \varGamma _{\kappa }(\tau )} \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}} \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } (x_{2}-\varrho )^{\frac{\tau }{\kappa }-1}\nu ( \varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho (x_{2}-\varrho )^{\frac{\tau }{\kappa }-1} \nu (\varrho )\,d\varrho \biggr] \bigl(f_{1}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}} \\& \qquad {}\times \biggl( \int _{x_{1}}^{x_{2}} \biggl[{}_{x_{1}} \mathscr {I}_{\kappa }^{\tau }x_{2}\mu (x_{2}) \int _{x_{1}}^{\vartheta } (x_{2}- \varrho )^{\frac{\tau }{\kappa }-1}\nu (\varrho )\,d\varrho \\& \qquad {}- {}_{x_{1}}\mathscr {I}_{\kappa }^{\tau }\mu (x_{2}) \int _{x_{1}}^{ \vartheta }\varrho (x_{2}-\varrho )^{\frac{\tau }{\kappa }-1} \nu (\varrho )\,d\varrho \biggr] \bigl(f_{2}^{\prime }( \vartheta ) \bigr)^{2}\,d\vartheta \biggr)^{\frac{1}{2}}. \end{aligned}$$
(19)

Proof

Applying Theorem 3.2 with \(\varPsi (\vartheta )=\vartheta \) gives the proof of the theorem. □

Similarly, we can get several new inequalities in terms of the Riemann–Liouville κ-fractional integrals for \(\varPsi (\vartheta )=\vartheta \) in Theorems 3.33.4. Also, employing Corollaries 3.13.12 for \(\varPsi (\vartheta )=\vartheta \) results in various new inequalities.

Remark 4.1

We can also establish other types of new inequalities by taking the following assumptions:

  1. i.

    Setting \(\mu (\vartheta )=\nu (\vartheta )\) and \(\varPsi (\vartheta )=\vartheta \) throughout the paper.

  2. ii.

    Setting \(\mu (\vartheta )=\nu (\vartheta )=1\) and \(\varPsi (\vartheta )=\vartheta \) throughout the paper.

Remark 4.2

If we take \(\kappa =1\), then all established results reduce to the work of Bezziou et al. [5].

Remark 4.3

Setting \(\mu (\vartheta )=\nu (\vartheta )\), \(\kappa =1\), and \(\varPsi (\vartheta )=\vartheta \) in Theorems 3.13.4 restores the results of Bezziou et al. [4].

5 Concluding remarks

In this present paper, we derived some double-weighted generalized fractional integral inequalities by employing the generalized Riemann–Liouville κ-fractional integrals containing another function Ψ in the kernels, where Ψ is integrable, measurable, positive, and monotone. We can quickly form many new fractional integral inequalities for different fractional definitions by considering Remark 2.2.