Let \(\mathbf{a}, \mathbf{b}\) and \(\mathbf{c}\) be three vectors such that $\mathbf{a} \times \mathbf{b} = \mathbf{a} \times \mathbf{c} \text{ and } \mathbf{a} \times \mathbf{b} \neq 0 \text{ Show that } \mathbf{b} = \mathbf{c}$.
Find the domain of the function \( f(x) = \cos^{-1}(x^2 - 4) \).
Match the following:In the following, \( [x] \) denotes the greatest integer less than or equal to \( x \). Choose the correct answer from the options given below:
For x < 0: f(x) = ex + ax
For x ≥ 0: f(x) = b(x - 1)2