Determinants - Texas A&M University

Note that any minor of a 3×3 matrix is a 2×2 matrix, and hence its determinant is defined. We also wish to stress that we did not have to expand across the first row. We could have used any row or column. Example 3. Compute the determinant ofthe matrix below by expandingacross the first row and also by expanding down the second column. A= ................
................