Trigonometry (11th Edition) Clone

$w\cdot z$ = $36(cos130^\circ + isin130^\circ)$
$w = 12(cos80^\circ + isin80^\circ) = 12cis80^\circ$ $z = 3(cos50^\circ + isin50^\circ) = 3cis50^\circ$ Now, $w\cdot z$ = $12cis80^\circ \cdot 3cis50^\circ$ = $12 \cdot 3 \cdot cis(80^\circ+ 50^\circ)$ (Product Theorem) = $36cis130^\circ$ = $36(cos130^\circ + isin130^\circ)$