Solution
= Solution
As $x\to\infty$, $\cos^2(1/x)\to1$. It is therefore at least $1/2$ on some infinite tail. The integral of that lower bound is infinite, so \b[it is not integrable] on this interval.
= Solution
As $x\to\infty$, $\cos^2(1/x)\to1$. It is therefore at least $1/2$ on some infinite tail. The integral of that lower bound is infinite, so \b[it is not integrable] on this interval.