TeX source:

\frac{\mathbf{d}}{\mathbf{d t}} 3^{\left(\mathrm{t}^{2}\right)}=3^{\left(\mathrm{t}^{2}\right)} \ln (3) \mathbf{D}\left(\mathrm{t}^{2}\right)=3^{\left(\mathrm{t}^{2}\right)} \ln (3) \cdot 2 \mathrm{t}