MathDB
S has at most six elements

Source:

August 30, 2010
algebrasystem of equationslinear algebraIMO ShortlistIMO Longlist

Problem Statement

Let a,b,ca, b, c be positive real numbers and p,q,rp, q, r complex numbers. Let SS be the set of all solutions (x,y,z)(x, y, z) in C\mathbb C of the system of simultaneous equations ax+by+cz=p,ax + by + cz = p,ax2+by2+cz2=q,ax2 + by2 + cz2 = q,ax3+bx3+cx3=r.ax3 + bx3 + cx3 = r. Prove that SS has at most six elements.