Question

Find the product, if possible of : $\left[\begin{array}{ccc}1&-1\\-1&1\end{array}\right] \left[\begin{array}{ccc}1&1\\1&1\end{array}\right]$

Answer 1

Answer:

$\left[\begin{array}{ccc}0&3\\0&-3\end{array}\right]$

Step-by-step explanation:

$\left[\begin{array}{ccc}1&-1\\-1&1\end{array}\right] \left[\begin{array}{ccc}1&1\\1&1\end{array}\right]$

$=\left[\begin{array}{ccc}1 \times 1 + (-1) \times 1&(-1) \times 1 + (-1) \times (-2)\\(-1) \times 1 + 1 \times 1&(-1) \times 1 + 1 \times (-2)\end{array}\right]$

$=\left[\begin{array}{ccc}0&3\\0&-3\end{array}\right]$