Consider the vectors shown in the figure.

1. The figure shows vectors in $\mathbb{R}^n$ for $n =$ . The zero vector in this vector space is written as $\mathbf{0} =$ (use coordinate vector notation, not ijk-vector notation).
2. If possible, find a nonzero linear combination of the vectors in the set $\lbrace \mathbf{a_1}, \mathbf{a_2}, \mathbf{a_3} \rbrace$ that equals $\mathbf{0}$. If this is not possible, enter DNE. Use the names of vectors in your answer (e.g., enter a1 for $\mathbf{a_1}$). Do not enter coordinate representations such as $\langle 1, 3 \rangle$.
   $= \mathbf{0}$.