Sum x^k/k! + 1 = 0 has no rational roots
Source: IMO Shortlist 1989, Problem 4, ILL 7
September 18, 2008
algebraequationpolynomialDiophantine equationRational rootsIMO Shortlist
Problem Statement
Prove that the equation \sum^n_{k\equal{}1} \frac{x^k}{k!} \plus{} 1 \equal{} 0 has no rational roots.