Find the angle θ between the vectors \(\vec a = \;\hat i - \;2\hat j + \;3\hat k\) and \(\vec b = \;3\hat i - \;2\hat j + \;\hat k\) ?
1
\({\cos ^{ - 1}}\left( {\frac{4}{7}} \right)\)
2
\({\cos ^{ - 1}}\left( {\frac{5}{7}} \right)\)
3
\({\cos ^{ - 1}}\left( {\frac{5}{9}} \right)\)
4
None of these
5
Question Not Attempted