Higher order linear non-homogeneous differential equation solving methods

As to the solution of higher order constant coefficient non-homogeneous linear differential equation,domestic teaching Ordinary Differential Equations used to solve it with undetermined coefficient method.When the order of the equation is higher,this method is more complicated.Besides introducing the undetermined coefficient method for order equation,but also introduced the constant variation method,Laplace transform method,the differential operator method,and analyzed the advantages and disadvantages of various solution of the equation as well as the types of proper equation.