Question

Compute the products Ax in Exercises 16 through 19

using paper and pencil (if the products are defined).

17.

$\left[\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\end{array}\right]\mathbf{.}\left[\begin{array}{c}7\\ 8\end{array}\right]$

Short answer

The dot product of $\left[\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\end{array}\right].\left[\begin{array}{c}7\\ 8\end{array}\right]$is not defined

Step-by-step solution

Step 1:

For the first matrix, $\left[\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\end{array}\right]$

The number of columns m= 3

For the second matrix _{$\left[\begin{array}{c}7\\ 8\end{array}\right]$}

The number of rows n= 2 n= 2

Therefore, we have m≠n.

Hence, dot product is not possible.

Final answer:

The dot product of$\left[\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\end{array}\right].\left[\begin{array}{c}7\\ 8\end{array}\right]$is not defined