$$\frac { d y } { d x } y = 3 \sin x + 4 c ^ { 2 / 3 } x$$
$\left\{\begin{matrix}c=\frac{3\sqrt{-3\times \left(\frac{\sin(x)}{x}\right)^{3}}}{8}\text{; }c=-\frac{3\sqrt{-3\times \left(\frac{\sin(x)}{x}\right)^{3}}}{8}\text{, }&\exists n_{1}\in \mathrm{Z}\text{ : }x=\pi n_{1}\text{ and }x\neq 0\\c\in \mathrm{R}\text{, }&x=0\end{matrix}\right.$
