\(-7-9i\\ r = \sqrt{(-7)^2+(-9)^2} = \sqrt{130} \\ \alpha = tan^{-1}(\frac{-9}{-7}) \Leftrightarrow \alpha =52^\circ 7' 30{,}1"\text{ of } \alpha = 232^\circ 7' 30{,}1"\\-7-9i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 232^\circ 7' 30{,}1"\)