MathDB
P,Q

Source: Iran 2005

August 27, 2005
functionratioalgebra proposedalgebra

Problem Statement

Suppose P,QR[x]P,Q\in \mathbb R[x] that deg P=deg Qdeg\ P=deg\ Q and PQQPPQ'-QP' has no real root. Prove that for each λR\lambda \in \mathbb R number of real roots of PP and λP+(1λ)Q\lambda P+(1-\lambda)Q are equal.