In this paper, we introduce an additive functional inequality and a quadratic functional inequality in normed spaces, and prove the Hyers-Ulam stability of the functional inequalities in Banach spaces. Furthermore, we...In this paper, we introduce an additive functional inequality and a quadratic functional inequality in normed spaces, and prove the Hyers-Ulam stability of the functional inequalities in Banach spaces. Furthermore, we introduce an additive functional inequality and a quadratic functional inequality in non-Archimedean normed spaces, and prove the Hyers-Ulam stability of the functional inequalities in non-Archimedean Banach spaces.展开更多
In the present paper, we establish the stability and the superstability of a functional inequality corresponding to the functional equation fn(xyx) = ∑i+j+k=n fi(x)fj (y)fk(x). In addition, we take account ...In the present paper, we establish the stability and the superstability of a functional inequality corresponding to the functional equation fn(xyx) = ∑i+j+k=n fi(x)fj (y)fk(x). In addition, we take account of the problem of Jacobson radical ranges for such functional inequality.展开更多
基金Supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education,Science and Technology(Grant No.NRF-2012R1A1A2004299)
文摘In this paper, we introduce an additive functional inequality and a quadratic functional inequality in normed spaces, and prove the Hyers-Ulam stability of the functional inequalities in Banach spaces. Furthermore, we introduce an additive functional inequality and a quadratic functional inequality in non-Archimedean normed spaces, and prove the Hyers-Ulam stability of the functional inequalities in non-Archimedean Banach spaces.
基金supported by Korea Research Foundation Grant funded by the Korean Government,KRF-2008-531-C00008
文摘In the present paper, we establish the stability and the superstability of a functional inequality corresponding to the functional equation fn(xyx) = ∑i+j+k=n fi(x)fj (y)fk(x). In addition, we take account of the problem of Jacobson radical ranges for such functional inequality.