Sketch the graph of $f$ by hand and use your sketch to find the absolute and local maximum and minimum values of $f .$ (Use the graphs and transformations of Sections 1.2 and $1.3 .$ )
$\mathrm{f}(\mathrm{t})=\cos t, \quad-3 \pi / 2 \leqslant \mathrm{t} \leqslant 3 \pi / 2$