Variation of Parameter for higher order eqautions

[Sophie Liao]

Since we have learned the variation of parameter method for second and third order equation, I just want to confirm whether my idea is correct or not. For fourth order eqatuion or higher, should we compute the det of 4 by 4 matrix or even higher to use this method? Is there any general theorem for this method?

[shiyuancao]

I think your idea is correct and it's unmistakable to apply the same principle when solving higher order equations