Generalized Stabilities of Euler-Lagrange-Jensen (a,b)-Sextic Functional Equations in Quasi-β-Normed Spaces
Main Article Content
Abstract
The aim of this paper is to investigate generalized Ulam-Hyers stabilities of the following Euler-Lagrange-Jensen-$(a,b)$-sextic functional equation
$$
f(ax+by)+f(bx+ay)+(a-b)^6\left[f\left(\frac{ax-by}{a-b}\right)+f\left(\frac{bx-ay}{b-a}\right)\right]\\
= 64(ab)^2\left(a^2+b^2\right)\left[f\left(\frac{x+y}{2}\right)+f\left(\frac{x-y}{2}\right)\right]\\
+2\left(a^2-b^2\right)\left(a^4-b^4\right)[f(x)+f(y)]
$$
where $a\neq b$, such that $k\in \mathbb{R}$; $k=a+b\neq 0,\pm1$ and $\lambda=1+(a-b)^6-2\left(a^6+b^6\right)-62(ab)^2\left(a^2+b^2\right)\neq 0$, in quasi-$\beta$-normed spaces by using fixed point method. In particular, we prove generalized stabilities involving the sum of powers of norms, product of powers of norms and the mixed product-sum of powers of norms of the above functional equation in quasi-$\beta$-normed spaces by using fixed point method. A counter-example for a singular case is also indicated.Article Details
References
- J. Aczel, Lectures on Functional Equations and their Applications, Vol. 19, Academic Press, New York, 1966.
- J. Aczel, Functional Equations, History, Applications and Theory, D. Reidel Publ. Company, 1984.
- C. Alsina, On the stability of a functional equation, General Inequalities, Vol. 5, Oberwolfach, Birkhauser, Basel, (1987), 263-271.
- T. Aoki, On the stability of the linear transformation in Banach spaces, J. Math. Soc. Japan, 2 (1950), 64-66.
- L. Cadariu and V. Radu, Fixed points and stability for functional equations in probabilistic metric and random normed spaces, Fixed Point Theory Appl. 2009 (2009), Art. ID 589143, 18 pages.
- B. Bouikhalene and E. Elquorachi, Ulam-Gavruta-Rassias stability of the Pexider functional equation, Int. J. Appl. Math. Stat., 7 (2007), 7-39.
- I. S. Chang and H. M. Kim, On the Hyers-Ulam stability of quadratic functional equations, J. Ineq. Appl. Math. 33 (2002), 1-12.
- I. S. Chang and Y. S. Jung, Stability of functional equations deriving from cubic and quadratic functions, J. Math. Anal. Appl., 283 (2003), 491-500.
- J. K. Chung and P. K. Sahoo, On the general solution of a quartic functional equation, Bull. Korean Math. Soc., 40 (4) (2003), 565-576.
- S. Czerwik, Functional Equations and Inequalities in Several Variables, World Scientific Publishing Company, New Jersey, London, Singapore and Hong Kong, 2002.
- M. Eshaghi Gordji, S. Zolfaghari, J. M. Rassias and M. B. Savadkouhi, Solution and stability of a mixed type cubic and quartic functional equation in quasi-Banach spaces, Abst. Appl. Anal., 2009 (2009), Art. ID 417473.
- Z. Gajda, On stability of additive mappings, Int. J. Math. Math. Sci. 14 (3) (1991), 431-434.
- N. Ghobadipour and C. Park, Cubic-quartic functional equations in fuzzy normed spaces, Int. J. Nonlinear Anal. Appl., 1 (2010), 12-21.
- P. Gˇ avrutˇ a, A generalization of the Hyers-Ulam-Rassias stability of approximately additive mappings, J. Math. Anal. Appl., 184 (1994), 431-436.
- Heejeong Koh and Dongseung Kang, Solution and stability of Euler-Lagrange-Rassias quartic functional equations in various quasi-normed spaces, Abstr. Appl. Anal., 2013 (2013), Art. ID 908168, 8 pages.
- D. H. Hyers, On the stability of the linear functional equation, Proc. Nat. Acad. Sci., U.S.A., 27 (1941), 222-224.
- D. H. Hyers, G. Isac and Th. M. Rassias, Stability of Functional Equations in Several Variables, Birkhauser, Basel, 1998.
- G. Isac and Th. M. Rassias, Stability of ψ-additive mappings: applications to nonlinear analysis, Int. J. Math. Math. Sci., 19(2) (1996), 219-228.
- K. W. Jun and H. M. Kim, On the stability of Euler-Lagrange type cubic mappings in quasi-Banach spaces, J. Math. Anal. Appl. 332(2) (2007), 1335-1350.
- S. M. Jung, Hyers-Ulam-Rassias stability of functional equations in Mathematical Analysis, Hardonic press, Palm Harbor, 2001.
- Pl. Kannappan, Quadratic Functional Equation and Inner Product Spaces, Results Math. 27(3-4) (1995), 368-372.
- J. R. Lee, D. Y. Shin and C. Park, Hyers-Ulam stability of functional equations in matrix normed spaces, J. Inequal. Appl. 2013 (2013), Art. ID 22.
- E. Movahednia, Fixed point and generalized Hyers-Ulam-Rassias stability of a quadratic functional equation, J. Math. Comput. Sci., 6 (2013), 72-78.
- A. Najati and C. Park, Cauchy-Jensen additive mappings in quasi-Banach algebras and its applications, J. Nonlinear Anal. Appl., 2013 (2013), Art. ID jnaa-00191.
- P. Nakmahachalasint, Hyers-Ulam-Rassias and Ulam-Gavruta-Rassias stabilities of additive functional equation in several variables, Int. J. Math. Math. Sci. 2007 (2007) Art. ID 13437, 6 pages.
- C. Park, Fixed points and the stability of an AQCQ-functional equation in non-Archimedean normed spaces, Abstr. Appl. Anal., 2010 (2010) Art. ID 849543, 15 pages.
- C. G. Park, Stability of an Euler-Lagrange-Rassias type additive mapping, Int. J. Appl. Math. Stat., 7 (2007), 101-111.
- A. Pietrzyk, Stability of the Euler-Lagrange-Rassias functional equation, Demonstr. Math., 39(3) (2006), 523 - 530.
- J. M. Rassias, On approximately of approximately linear mappings by linear mappings, J. Funct. Anal. 46 (1982), 126-130.
- J. M. Rassias, On approximately of approximately linear mappings by linear mappings, Bull. Sci. Math., 108 (4) (1984), 445-446.
- J. M. Rassias, On a new approximation of approximately linear mappings by linear mappings, Discuss. Math., 7 (1985), 193-196.
- J. M. Rassias, On the stability of the Euler-Lagrange functional equation, Chinese J. Math., 20 (1992), 185-190.
- J. M. Rassias, On the stability of the non-linear Euler-Lagrange functional equation in real normed linear spaces, J. Math. Phys. Sci., 28 (1994), 231-235.
- J .M. Rassias, On the stability of the general Euler-Lagrange functional equation, Demonstr. Math., 29 (1996), 755-766.
- J. M. Rassias, Solution of the Ulam stability problem for Euler-Lagrange quadratic mappings, J. Math. Anal. Appl., 220 (1998), 613-639.
- J. M. Rassias, On the stability of the multi-dimensional Euler-Lagrange functional equation, J. Indian Math. Soc., 66 (1999), 1-9.
- J. M. Rassias, Solution of the Ulam stability problem for quartic mappings, Glasnic Matematicki. Serija III, 34(2) (1999), 243-252.
- J. M. Rassias, Solution of the Ulam stablility problem for cubic mappings, Glasnik Matematicki. Serija III, 36(1) (2001), 63-72.
- K. Ravi, M. Arunkumar and J. M. Rassias, Ulam stability for the orthogonally general Euler-Lagrange type functional equation, Int. J. Math. Stat. 3(A08) (2008), 36-46.
- K. Ravi, J. M. Rassias, M. Arunkumar and R. Kodandan, Stability of a generalized mixed type additive, quadratic, cubic and quartic functional equation, J. Inequ. Pure Appl. Math., 10(4) (2009), 1-29.
- Th. M. Rassias, On the stability of the linear mapping in Banach spaces, Proc. Amer. Math. Soc., 72 (1978), 297-300.
- S. M. Ulam, Problems in Modern Mathematics, Rend. Chap. VI, Wiley, New York, 1960.
- T. Z. Xu, J. M. Rassias and W. X. Xu, A fixed point approach to the stability of a general mixed AQCQ-functional equation in non-Archimedean normed spaces, Discrete Dyn. Nat. Soc. 2010 (2010) Art. ID 812545, 24 pages.
- T. Z. Xu, J. M. Rassias, M. J. Rassias and W. X. Xu, A fixed point approach to the stability of quintic and sextic functional equations in quasi-β-normed spaces,J. Inequal. Appl., 2010 (2010), Art. ID 423231.
- T. Z. Xu, J. M. Rassias and W. X. Xu, A fixed point approach to the stability of a general mixed additive-cubic functional equation in quasi fuzzy normed spaces, Int. J. Phys. Sci. 6(2) (2011), 313-324.