Give a Counterexample Showing That the Statement "If $\mathbf { a } \times \mathbf { b } = \mathbf { a } \times \mathbf { c }$

Essay

Give a counterexample showing that the statement "If $\mathbf { a } \times \mathbf { b } = \mathbf { a } \times \mathbf { c }$ , then b = c" is not always true.