fejér inequality

In this paper we find a characterization type result for (η1,η2)-convex functions. The Fejér integral inequality related to (η1,η2)-convex functions is obtained as a generalization of Fejér inequality related to the preinvex and η-convex functions. Also some Fejér trapezoid and midpoint type inequalities are given in the case that the absolute value of the derivative of considered function is (η1,η2)-convex.

In this article, we first establish weighted identities based on twice partially differentiable mappings. Moreover, utilizing this equality, we derive  the weighted Hermite-Hadamard type inequalities via co-ordinated convex mappings in a rectangle from the plane $\mathbb{R}^{2}$. More specifically, we establish new inequalities using the Holder and power-mean inequalities. In addition, we obtain new results with special choices.

‎We obtain some new Jensen-Mercer type inequalities for log-convex functions‎. ‎Indeed‎, ‎we establish refinement and reverse for the Jensen-Mercer inequality for log-convex functions‎. ‎Several new Hermite-Hadamard and Fej\'er types of inequalities are also presented‎.‎

Using the notion of eta-convex functions as generalization of convex functions, we estimate the difference between the middle and right terms in Hermite-Hadamard-Fejer inequality for differentiable mappings. Also as an application we give an error estimate for midpoint formula.