Xiao Ye insisted on buying a ticket for himself that day, but Tao Ying bought one for him as a symbol of sustaining his esteem, even though he didn't need one.
If vector \( \mathbf{a} = 3 \hat{i} + 2 \hat{j} - \hat{k} \) \text{ and } \( \mathbf{b} = \hat{i} - \hat{j} + \hat{k} \), then which of the following is correct?