MathDB
ax^3 - ax^2 + 9bx - b has 3 positive roots

Source: Polish MO Recond Round 1980 p4

September 9, 2024
algebrapolynomial

Problem Statement

Prove that if a a and b b are real numbers and the polynomial ax3ax2+9bxb ax^3 - ax^2 + 9bx - b has three positive roots, then they are equal.