\(-5+7i\\ r = \sqrt{(-5)^2+7^2} = \sqrt{74} \\ \alpha = tan^{-1}(\frac{7}{-5}) \Leftrightarrow \alpha =125^\circ 32' 15{,}6"\text{ of } \alpha = 305^\circ 32' 15{,}6"\\-5+7i\text{ ligt in kwadrant }2, \alpha \text{ ligt dus tussen }90^\circ \text{ en }180^\circ\\ \alpha = 125^\circ 32' 15{,}6"\)