Stability of linear differential equations of third order

The aim of this paper is to investigate the Hyers–Ulam stability of the linear differential equation y ( 3 ) ( t ) + α y ″ ( t ) + β y ′ ( t ) + γ y ( t ) = f ( t ) , where y ∈ C 3 [ a , b ] , f ∈ C [ a , b ] and − ∞ < a < b < + ∞ . More precisely, we prove that the equation y ( 3 ) ( t ) + α y ″ ( t ) + β y ′ ( t ) + γ y ( t ) = f ( t ) has the Hyers–Ulam stability.