Convert between Cartesian form and polar form, with and without technology.

Convert the complex number \(z = -3 + 4i\) to polar form \(z = r \operatorname{cis}(\theta)\), where \(r > 0\) and \(-\pi < \theta \leq \pi\).

The complex number $z = 4\operatorname{cis}\left(\frac{5\pi}{6}\right)$. Convert $z$ into Cartesian form, expressing your answer in exact form.

Which option correctly shows the polar form \(r \text{ cis } \theta\) of the complex number shown in the diagram, where \(r > 0\) and \(-\pi < \theta \leq \pi\)?