Answer:
Step-by-step explanation:
z1=6(cos\frac{3\pi}{2}+isin \frac{3\pi}{2})=6e^{i\frac{3 \pi}{2}} \\similarly~ z2=12e^{i\frac{5 \pi}{6}} \\z1z2=72e^{i(\frac{3 \pi}{2}+\frac{5 \pi}{6}} )\\=72e^{i(\frac{9 \pi+5 \pi}{6}} )\\=72e^{i \frac{7 \pi}{3}} \\=72(cos \frac{7 \pi}{3}+i sin \frac{7 \pi}{3})
