> [!NOTE] Lemma (Zero Vector)
> Let $n\geq 1.$ Let $\mathbb{R}^{n}$ denote the [[Real n-Space|real n-space]]. The [[Real Zero Vector|zero vector]] (or the origin of $\mathbb{R}^{n}$) is the [[Identity element of a binary operation|identity element]] of [[Addition in Real n-Space|real vector addition]]: that is, for all $\underline{v}\in \mathbb{R}^{n},$ $\underline{v}+\underline{0}=\underline{v}=\underline{0}+\underline{v}.$
Proof: Let $\underline{v}=(a_{1},a_{2},\dots,a_{n})\in \mathbb{R}^{n}$ by definition $\underline{v}+\underline{0}= \begin{pmatrix}
a_{1}+0 \\
a_{2}+0 \\
\vdots \\
a_{n}+0
\end{pmatrix} = \begin{pmatrix}
a_{1} \\
a_{2} \\
\vdots \\
a_{n}
\end{pmatrix}=
\begin{pmatrix}
0+a_{1} \\
0+a_{2} \\
\vdots \\
0+a_{n}
\end{pmatrix} = \underline{0}+\underline{v}.
$