1.
The value of 'aa' for which the scalar triple product formed by the vectors α=i^+aj^+k^\vec{\alpha} = \hat{i} + a\hat{j} + \hat{k}, β=j^+ak^\vec{\beta} = \hat{j} + a\hat{k} and γ=ai^+k^\vec{\gamma} = a\hat{i} + \hat{k} is maximum, is