Past exam of the mathematics course of the University of Cambridge 2007 iii Paper 13 3 ii Solution Created 2026-10-03 Updated 2026-10-14
Put and . If the assertion is immediate. Otherwise, supposeSince , this makes , so is sufficiently small to apply the maximum-influence logarithmic lower bound once is large. That bound givesFor all sufficiently large , the last quantity exceeds , contradicting . The choice of sufficiently large is independent of . Therefore