Let \(\vec a = \hat i - \hat j + \hat k\) and \(\vec b = \hat i + \hat j - \hat k\) then unit vector perpendicular to the plane containing \(\vec a\) and \(\vec b\) is
1
\(\frac{{\hat j\;+\;\hat k}}{{\sqrt 2 }}\)
2
\(\sqrt 2({\hat j + \hat k} )\)
3
\(\sqrt 2 ({\hat j - \hat k})\)
4
\(\frac{{\hat j\;-\;\hat k}}{{\sqrt 2 }}\)