Let a_{1} = \left [ \begin{matrix} 1 \\ -2 \\ 3 \end{matrix} \right ] , a_{2} = \left [ \begin{matrix} 5 \\ -13 \\ -3 \end{matrix} \right ] , and b = \left [ \begin{matrix} -3 \\ 8 \\ 1 \end{matrix} \right ] . Then Span { a_{1} , a_{2} } is a plane through the origin in \mathbb{R} ^3. Is b in that plane?