Exercise 2.4.27

Answers

(a) (row 3 of $A$ ) $⋅$ (column 1 or 2 of $B$ ) and (row 3 of $A$ ) $⋅$ (column 2 of $B$ ) are all zero.

(b) We have

[\begin{matrix} x \\ x \\ 0 \end{matrix}] [\begin{matrix} 0 & x & x \end{matrix}] = [\begin{matrix} 0 & x & x \\ 0 & x & x \\ 0 & 0 & 0 \end{matrix}]

and

[\begin{matrix} x \\ x \\ x \end{matrix}] [\begin{matrix} 0 & 0 & x \end{matrix}] = [\begin{matrix} 0 & 0 & x \\ 0 & 0 & x \\ 0 & 0 & x \end{matrix}],

both upper.

mathchakra

2021-12-06 17:52