2 Find the shortest distance between the lines \(\mathbf { r } = \left( \begin{array} { l } 2
1
0 \end{array} \right) + \lambda \left( \begin{array} { c } 1
2
- 1 \end{array} \right)\) and \(\mathbf { r } = \left( \begin{array} { c } - 1
1
2 \end{array} \right) + \mu \left( \begin{array} { l } 3
0
1 \end{array} \right)\).