A polynomial with negative roots
Source: Moldova TST 2010, day 2, problem 1
March 4, 2010
algebrapolynomialalgebra proposed
Problem Statement
Let p\in\mathbb{R}_\plus{} and k\in\mathbb{R}_\plus{}. The polynomial F(x)\equal{}x^4\plus{}a_3x^3\plus{}a_2x^2\plus{}a_1x\plus{}k^4 with real coefficients has negative roots. Prove that F(p)\geq(p\plus{}k)^4