Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge / 2022 / Paper 1 / 3

The domain excludes $x=0$. Rearranging the inequality givesA sign check on the intervals separated by $-1$ and $0$ shows that the ratio is nonnegative when $x\le -1$ or $x>0$. The point $-1$ is allowed because it makes the numerator zero. Therefore