Minors and cofactors

Compute the determinants of the following matrices using cofactor expansion along any row or column.

1. $\left[\begin{array}{rrr}1&2&0\\ 3&-2&2\\ 0&3&1\\ \end{array}\right]$

2. $\left[\begin{array}{rrr}1&-2&2\\ 3&0&0\\ 4&3&1\\ \end{array}\right]$

3. $\left[\begin{array}{rrrr}1&2&-2&2\\ 1&3&2&3\\ 4&0&1&0\\ 1&2&1&2\\ \end{array}\right]$

Find the following determinant by expanding (a) along the first row and (b) along the second column.

Find the following determinant by expanding (a) along the first column and (b) along the third row.

Find the following determinant by expanding (a) along the second row and (b) along the first column.

Compute the determinant by cofactor expansion. Pick the easiest row or column to use.