239. Given that $(\sin t)^{\prime}=\cos t$, differentiate the function $y=\sin 2 x$.
Solution. The complexity coefficient of the given function is 2. The order of the intermediate functions is as follows: $y=\sin u, u=2 x$. We find

$$
y^{\prime}=\cos 2 x \cdot(2 x)^{\prime}=\cos 2 x \cdot 2=2 \cos 2 x
$$