111. Find the general solution of the equation $y^{\prime \prime}=\sin 2 x$.
Solution. Multiply both sides of the equation by $d x$ and then integrate:

$$
d y^{\prime}=\sin 2 x d x ; \int d y^{\prime}=\int \sin 2 x d x ; y^{\prime}=-\frac{1}{2} \cos 2 x+C_{\mathrm{t}}
$$

Multiply both sides of the last equation by $d x$ and integrate:

$$
d y=-\frac{1}{2} \cos 2 x d x+C_{1} d x ; \int d y=-\frac{1}{2} \int \cos 2 x d x+C_{1} \int d x+C_{2}
$$

Thus, $y=-\frac{1}{4} \sin 2 x+C_{1} x+C_{2}$ - the general solution of the equation. 112-119. Find the general solutions of the equations: