TeX source:

\begin{align*}\begin{aligned}&\mathbf{D}(\sin (\cos (5 \mathrm{x})))=\cos (\cos (5 \mathrm{x})) \cdot \mathbf{D}(\cos (5 \mathrm{x}))=\cos (\cos (5 \mathrm{x})) \cdot(-\sin (5 \mathrm{x})) \cdot \mathbf{D}(5 \mathrm{x})=-5 \cdot \sin (5 \mathrm{x}) \cdot \cos (\cos (5 \mathrm{x})) \\&\frac{\mathrm{d}}{\mathrm{dx}} \mathrm{e}^{\cos (3 \mathrm{x})}=\mathrm{e}^{\cos (3 \mathrm{x})} \mathrm{D}(\cos (3 \mathrm{x}))=\mathrm{e}^{\cos (3 \mathrm{x})}(-\sin (3 \mathrm{x})) \mathbf{D}(3 \mathrm{x})=-3 \cdot \sin (3 \mathrm{x}) \cdot \mathrm{e}^{\cos (3 \mathrm{x})}\end{aligned}\end{align*}