Given :
a = 2i + j - 3k
\(\overline{a} = 2\hat{i} + \hat{j} - 3\hat{k}\) and \(\overline{b} = \hat{i} - 2\hat{j} + \hat{k}\)
∴ unit vectors perpendicular to both the vectors \(\overline{a}\) and \(\overline{b}.\)
∴ required vectors of magnitude 5 units
