The tag laplace-expansion seem to be used for two totally different, and unrelated subjects:
1) Laplace approximation for integrals, as in Laplace's method with nontrivial parameter dependency
2) Laplace expansion for calculating determinants, as used in https://math.stackexchange.com/questions/1122984/proof-for-determinants-using-laplace-and-induction
I guess the second use is the intended use, but as there (was) no tag wiki it's difficult to say!
Proposal: Define 2) as the intended use, and make a new tag laplace-approximation for 1)