Let $A \in \mathbb{R}^{2 \times 3}$ be a
D4571: Real matrix such that
| (i) |
$a_1, a_2, a_3 \in \mathbb{R}^{2 \times 1}$ are each a D5200: Real column matrix
|
| (ii) |
\begin{equation}
A
=
\begin{bmatrix}
a_1 & a_2 & a_3
\end{bmatrix}
=
\begin{bmatrix}
1 & 0 & 0 \\
0 & 1 & 1
\end{bmatrix}
\end{equation}
|
The second claim is clear. For any $x \in \mathbb{R}^{2 \times 1}$, we can just use the first two columns to write
\begin{equation}
x
= x_1 \cdot a_1 + x_2 \cdot a_2
\end{equation}
which establishes the first claim. $\square$
