TeX source:
\begin{array}{rclcl}z_1 = a^2 &=& \dfrac{5}{4} &\vert& \pm\sqrt{} \\a_{2,3} &=& \pm\sqrt{\dfrac{5}{4}} \approx \pm 1{,}12 \\\\z_2 = a^2 &=& -2 &\vert& \pm\sqrt{} \\a_{4,5} &=& \pm\sqrt{-2}\end{array}