Solution (source code)

= Solution

Although $\cos(1/x)$ oscillates without a <limit>, its magnitude is at most one. Therefore $|x\cos(1/x)|\leq|x|\to0$. The <squeeze theorem> gives
$$
\boxed{\lim_{x\to0}x\cos(1/x)=0.}
$$
The shrinking factor $x$ suppresses the oscillation from either side of zero.