This is LaTeX code:
[latex]
\begin{pmatrix} 1-\mu \\ -1+\mu \\ 1 \\ 0 \\ \end{pmatrix} + t \begin{pmatrix} -3 \\ 1 \\ 0 \\ 1 \\ \end{pmatrix}, \ t \in \mathbb{R}
[/latex]