Very strange inequality
Source: 1996 IMO Shortlist
June 11, 2006
inequalitiesalgebrapolynomialfunctioncalculusIMO Shortlist
Problem Statement
Let be non-negative reals, not all zero. Show that that
(a) The polynomial p(x) \equal{} x^{n} \minus{} a_{1}x^{n \minus{} 1} \plus{} ... \minus{} a_{n \minus{} 1}x \minus{} a_{n} has preceisely 1 positive real root .
(b) let A \equal{} \sum_{i \equal{} 1}^n a_{i} and B \equal{} \sum_{i \equal{} 1}^n ia_{i}. Show that .