On the Stability of a Mixed Type Functional Equation

Lee, Yang-Hi;Jung, Soon-Mo

  • Received : 2013.08.10
  • Accepted : 2013.09.30
  • Published : 2015.03.23


In this paper, we investigate the stability of the functional equation f(-x + y + z + w) + f(x - y + z + w) + f(x + y - z + w) + f(x + y + z - w) = 3f(x) + f(-x) + 3f(y) + f(-y) + 3f(z) + f(-z) + 3f(w) + f(-w) by using the direct method in the sense of Hyers.


generalized Hyers-Ulam stability;Hyers-Ulam stability;direct method;mixed type functional equation


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Supported by : National Research Foundation of Korea (NRF)