Past exam of the year 1 of the computer science course of the University of Oxford / 2019 / Discrete mathematics, continuous mathematics, and probability / 1 / c / ii

It is neither injective nor surjective onto $\mathbb{R}$, so it has no inverse function on the stated domain and codomain. The distinct inputs $0$ and $\pi /3$ both lie in the domain and both give zero. All values lie in $[-1,1]$, so, for example, the real number $2$ has no preimage.