Lagrange＇s variation-of-constants method for solving linear inhomogeneous ordinary differential equations （ode＇s） is replaced by a method based on the Loewy decomposition of the corresponding homogeneous equation....Lagrange＇s variation-of-constants method for solving linear inhomogeneous ordinary differential equations （ode＇s） is replaced by a method based on the Loewy decomposition of the corresponding homogeneous equation. It uses only properties of the equations and not of its solutions. As a consequence it has the advantage that it may be generalized for partial differential equations （pde＇s）. It is applied to equations of second order in two independent variables, and to a certain system of third-order pde＇s. Therewith all possible linear inhomogeneous pde＇s are covered that may occur when third-order linear homogeneous pde＇s in two independent variables are solved.展开更多
文摘Lagrange＇s variation-of-constants method for solving linear inhomogeneous ordinary differential equations （ode＇s） is replaced by a method based on the Loewy decomposition of the corresponding homogeneous equation. It uses only properties of the equations and not of its solutions. As a consequence it has the advantage that it may be generalized for partial differential equations （pde＇s）. It is applied to equations of second order in two independent variables, and to a certain system of third-order pde＇s. Therewith all possible linear inhomogeneous pde＇s are covered that may occur when third-order linear homogeneous pde＇s in two independent variables are solved.
