$($The arrays in MATLAB are one$-$based: the first element is $x(1)$ not $x(0).)$ Justify the values you see in the array $x$ by first analytically determining the spectrum for $x(t)=cost.$

Now, create a square wave:

$n=0$:$255$;

$t=\frac{n}{256}$;

ones $(1,64),-$ ones $(1,64),$ ones $(1,64),-$ ones $(1,64)$;

$>$ plot $(t,x)$;

Find the FFT spectrum of this square wave and plot it$.$ Explain the magnitudes and frequencies of the FFT spectral lines.