Let v_{1} = \left [ \begin{matrix} 1 \\ 2 \end{matrix} \right ] \text{and} v_{2} = \left [ \begin{matrix} 6 \\ 0 \end{matrix} \right ] , and let L_{1} be the line through v_{1} and v_{2} . Find a linear functional f and a constant d such that L_{1} = [f : d] .