Problem $7(10$pt$).$ Use Matlab to compute and graph the following signal, for the interval $n=-20...,59.$ Please add both the Matlab code and the graph in your report.

$x_3[n]=\{\begin{array}{ccc}sin(0\mathrm{.}2n),& n=0,...,& 39\\ 0,& \text{o}\text{t}\text{h}\text{e}\text{r}\text{w}\text{i}\text{s}\text{e}& \end{array}$