Write the Product $$z _ { 1 } z _ { 2 }$$

Essay

Write the product $$z _ { 1 } z _ { 2 }$$ , and quotient $$z _ { 1 } / z _ { 2 }$$ , of $$z _ { 1 } = 2 \left( \cos \frac { 5 \pi } { 6 } + i \sin \frac { 5 \pi } { 6 } \right)$$ and $$z _ { 2 } = 5 \left( \cos \frac { \pi } { 3 } + i \sin \frac { \pi } { 3 } \right)$$ in polar form.