Plot several typical solutions of the equation y_{k+1} = Dy_{k} , where
D = \left[ \begin{matrix} 2.0 & 0 \\ 0 & 0.5 \end{matrix} \right]
(We write D and y here instead of A and x because this example will be used later.) Show that a solution \{y_{k}\} is unbounded if its initial point is not on the x_{2} -axis.