Exercise 2

Compute the determinant of each of these by hand using the two methods discussed above.

• (a)  $\begin{vmatrix}2&1\\ 5&-3\end{vmatrix}$     (b)  $\begin{vmatrix}3&1&1\\ -1&0&5\\ -1&2&-2\end{vmatrix}$     (c)  $\begin{vmatrix}2&1&0&0\\ 1&3&2&0\\ 0&-1&-2&1\\ 0&0&-2&1\end{vmatrix}$

Count the number of multiplications and divisions used in each case, for each of the methods.