TeX source:

D\left(x^{2} \cdot \sin \left(x^{2}+3\right)\right)=x^{2}\left\{\cos \left(x^{2}+3\right)\right\}(2 x)+\left\{\sin \left(x^{2}+3\right)\right\}(2 x)=2 x\left\{x^{2} \cdot \cos \left(x^{2}+3\right)+\sin \left(x^{2}+3\right)\right\}