Skip to main content
Log in

Multiplicative type functional equations in a ring

  • Published:
Aequationes mathematicae Aims and scope Submit manuscript

Abstract

Let R be a ring, \({\mathbb{F}}\) be a field and \({K \subset \mathbb{R}}\) an integral domain. In this paper we investigate general solutions \({f : K^2\to \mathbb{R}^+}\) of the functional equations

$$\begin{array}{ll}f(ux-vy, uy+vx)\,=\,f(x, y)f(u, v),\\f(ux+vy, uy-vx)\,=\,f(x, y)f(u, v)\end{array}$$

for all \({x, y\in K}\), and general solutions \({f:R^2\to \mathbb{R}^+}\) of the functional equations

$$\begin{array}{ll}f(ux+vy, uy+vx)\,=\,f(x, y)f(u, v),\\ f(ux-vy, uy-vx)\,=\,f(x, y)f(u, v)\end{array}$$

for all \({x, y\in R}\). The above functional equations arise from number theory and are connected with the characterizations of the determinant and permanent of two-by-two matrices.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Albert M., Baker J.A.: Bounded solutions of a functional inequality. Can. Math. Bull. 25, 491–495 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  2. Baker J.A., Lawrence J., Zorzitto F.: The stability of the equation f(x + y)) = f(x)f(y). Proc. Am. Math. Soc. 74, 242–246 (1979)

    MathSciNet  MATH  Google Scholar 

  3. Chung, J.: On an exponential functional inequality and its distributional version. Can. Math. Bull. doi:10.4153/CMB-2014-012-x

  4. Chung, J., Chang, J.: On two functional equations originating from number theory, to appear in Proc. Indian Acad. Sci.

  5. Chung, J., Riedel, T., Sahoo, P.K.: Stability of functional equations arising from number theory and determinant of matrices (preprint)

  6. Chung J.K., Sahoo P.K.: General solution of some functional equations related to the determinant of some symmetric matrices. Demonstratio Math. 35, 539–544 (2002)

    MathSciNet  MATH  Google Scholar 

  7. Chudziak J., Tabor J.: On the stability of the Goła̧b-Schinzel functional equation. Jour. Math. Anal. Appl. 302, 196–200 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  8. Hyers, D.H., Isac, G., Rassias, Th.M.: Stability of functional equations in several variables. Birkhauser (1998)

  9. Houston K.B., Sahoo P.K.: On two functional equations and their solutions. Appl. Math. Lett. 21, 974–977 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  10. Jung S.M., Bae J.H.: Some functional equations arising from number theory. Proc. Indian Acad. Sci. Math. Sci. 113(2), 91–98 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  11. Lehmer D.H.: A cotangent analogue of continued fractions. Duke Math. J. 4(2), 323–340 (1938)

    Article  MathSciNet  MATH  Google Scholar 

  12. Riedel T., Sahoo P.K.: On a generalization of a functional equation associated with the distance between the probability distributions. Publ. Math. Debrecen 46(1–2), 125–135 (1995)

    MathSciNet  MATH  Google Scholar 

  13. Najdecki, J.A.: On stability of functional equation connected with the Reynolds operator. J. Inequal. Appl. 2007, Article ID 79816, 3 pages (2007)

  14. Sahoo, P.K.: Solved and unsolved problems, problem 2, News Letter of the European Math. Soc., 58, 43–44 (2005)

  15. Taussky O.: Sums of squares. Am. Math. Monthly 77, 805–830 (1970)

    Article  MathSciNet  MATH  Google Scholar 

  16. Todd J.: A problem on arc tangent relations. Am. Math. Monthly 56, 517–528 (1949)

    Article  MathSciNet  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Jeongwook Chang.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chung, J., Chang, J. Multiplicative type functional equations in a ring. Aequat. Math. 90, 367–379 (2016). https://doi.org/10.1007/s00010-015-0340-8

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00010-015-0340-8

Mathematics Subject Classification

Keywords

Navigation