MathDB
ineq lp

Source: L. Panaitopol, Romania, TST 1987

August 10, 2005
algebrapolynomialinequalitiesvectorinequalities proposed

Problem Statement

Let P(X) \equal{} a_{n}X^{n} \plus{} a_{n \minus{} 1}X^{n \minus{} 1} \plus{} \ldots \plus{} a_{1}X \plus{} a_{0} be a real polynomial of degree n n. Suppose n n is an even number and: a) a0>0 a_{0} > 0, an>0 a_{n} > 0; b) a_{1}^{2} \plus{} a_{2}^{2} \plus{} \ldots \plus{} a_{n \minus{} 1}^{2}\leq\frac {4\min(a_{0}^{2} , a_{n}^{2})}{n \minus{} 1}. Prove that P(x)0 P(x)\geq 0 for all real values x x. Laurentiu Panaitopol