The determinant of a matrix is a scalar value that factors into numerous properties of the matrix. It is also quite expensive to compute, involving
It has numerous definitions. Wikipedia says that the most common one is the “Leibniz definition,” but that involves a lot of math that I don’t know. ChatGPT tells me that we can take one of the formulas for calculating it, the Laplace expansion, as definitional. It is defined recursively:
Base case:
Inductive step (
where