Determining a Particular Solution for Systems of Linear Differential Equations with Constant Coefficients that Have on the Column of Free Terms Functions Such As e a · x · P ( x ) ·cos n x or e b · x · Q ( x )·sin n x

Abstract The determination of a particular solution for the systems of linear differential equations with constant coefficients that have on the column of free terms functions such as e a · x · P ( x ) ·cos n x or e b · x · Q ( x )·sin n x , or/and e b · x · Q ( x ) sin n x , n ∈ N , is based on the expansion of cos n x and sin n x , and, on the other hand, on how a particular solution for a column of free terms with functions such as e a · x · P ( x ) ·cos n x or e b · x · Q ( x )·sin n x, n ∈ N , looks like. We can also write the way a particular solution looks like when we have a combination of two or more functions on the form e a · x · P ( x ) ·cos n x or e b · x · Q ( x )·sin n x , n ∈ N in the column of free terms.