Past exam of the mathematics course of the University of Cambridge 2023 ia Paper 1 11E c Solution Created 2026-09-24 Updated 2026-10-03
No. The Darboux theorem says that every derivative has the intermediate-value property. Choose . In a deleted neighborhood of , the assumed limit puts within of . Darboux's theorem applied between and any such would require values near , which that neighborhood excludes. This contradiction shows that cannot be a derivative.