Title of article :
Boundedness of approximate trigonometric functions
Author/Authors :
Kim، نويسنده , , Gwang Hui and Lee، نويسنده , , Young Whan، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Abstract :
In this work, we prove that approximate trigonometric functions are bounded. That is, if a non-zero function f satisfies the inequality | f ( x + y ) − f ( x − y ) − 2 f ( x ) f ( y ) | ≤ φ ( x ) or φ ( y ) , then f is bounded.
Keywords :
Alembert equation , Sine functional equation , Trigonometric functional equation , Functional inequality
Journal title :
Applied Mathematics Letters
Journal title :
Applied Mathematics Letters
