Multi-Row Expansion of Determinants: 2-Row Laplace Expansion Demo

Step-by-Step Process (Column Combinations C(n,2))

Term Column Combo Sign 2x2 Minor Cofactor Term Value Cumulative Sum

Basic Introduction

Multi-row expansion is a generalization of Laplace expansion. Select k rows (fixed as k=2 on this page), then enumerate the same number of column combinations.

Each term has the form:

(-1)^(sum of row indices + sum of column indices) × minor × cofactor

Here "cofactor" refers to the minor determinant obtained by removing the selected rows and columns.

Applications

  • For certain structured matrices, multi-row expansion is more efficient than single-row expansion.
  • It is a common tool for studying block determinants, Vandermonde structures, and algebraic identities.