The angle between the lines \(\rm \vec r=3\hat i+2\hat j-4\hat k+\lambda(\hat i+2\hat j+2\hat k)\) and \(\rm \vec r=5\hat j-2\hat k+\mu(3\hat i+2\hat j+6\hat k)\) is:
1
\(\rm \sin^{-1}\left(\frac{19}{21}\right)\)
2
\(\rm \cos^{-1}\left(\frac{19}{23}\right)\)
3
\(\rm \cos^{-1}\left(\frac{19}{21}\right)\)
4
More than one of the above
5
None of the above