Problem $2$: Use MATLAB to plot the functions $z_1(t)=e^t,z_2(t)=2u(t+1),$ and $z_3(t)=0\mathrm{.}5sin(7t)$ for $t=-2$ to $2.$ Plot $z_1(t)$ function as a solid line, $z_2(t)$ as a dotted line, and $z_3(t)$ as a dashed line, and turn the plotting grid on$.$ Make sure to label both axes, title your figure, and turn on the plotting legend. Set the $y-$axis limits to $[-18].$

How do I type my answer into MATLAB?