Question

check answer @thesmartone

Answer 1

looks good

you use the formula I'm attaching (at the top of page 486)

http://college.cengage.com/mathematics/larson/elementary_linear/5e/students/ch08-10/chap_8_3.pdf

Answer 2

Thank you @jim_thompson5910

Answer 3

hint:
\[\begin{gathered}
z = r{e^{i\theta }} \hfill \\
w = \rho {e^{i\varphi }} \hfill \\
\frac{z}{w} = \frac{r}{\rho }{e^{i\left( {\theta - \varphi } \right)}} \hfill \\
\end{gathered} \]

Answer 4

you're welcome