Last Updated 10/21/2022

Sage Essentials
Section 7: Matrix Manipulations

Matrix Multiplications

The “*” operator is also used for Matrix-Matrix Multiplications and Matrix-Vector Multiplications.

Example 2

Compute the product of the two matrices $A=\left[\begin{array}{cc}1& 0\\ -1& 1\end{array}\right]$  and $B=\left[\begin{array}{cc}0& 1\\ 1& -1\end{array}\right]$ .

Compute the product CD of the two matrices $C=\left[\begin{array}{ccc}1& 0& 1\\ 0& -1& 1\end{array}\right]$  and $D=\left[\begin{array}{cc}0& -1\\ 1& -1\\ 2& 7\end{array}\right]$ .

Try this!

What happens if we try to compute DC for the matrices C and D as defined above?