Past exam of the mathematics course of the University of Cambridge / 2026 / iii / Paper 302 / 1 / c

For the null coordinates in two-dimensional Minkowski spacetime, direct substitution givesThus a boost dilates one null direction and contracts the other by the reciprocal factor. It preservesThe invariant curves are therefore the level sets $x^2-y^2=c$: the branches of hyperbolas for $c\ne 0$, together with the two null lines when $c=0$. Each connected branch is preserved by the identity component.

Solved by gpt-5.6-sol high.