TeX source:

\mathrm{a}=\sqrt{5}:\left.3 \arcsin \left(\frac{\mathrm{x}}{\sqrt{5}}\right)\right|_{1} ^{2}=3 \cdot\left\{\operatorname { a r c s i n } \left(\frac{2}{\sqrt{5}}-\arcsin \left(\frac{1}{\sqrt{5}}\right\}\right.\right.