Variation of Parameters vs Undetermined Co-efficients

[Marcus Tutert]

Do you care which method we use to solve a question? I prefer the former, as it is less guess work, but I wanted to make sure that if we just wanted to use one to solve questions that is fine

[Victor Ivrii]

Method of variation of parameters is much more general. However in some special situations the method of undermined coefficients works faster. And you need to know how in these situations solutions look like. Unless method is indicated you can use any.