MathDB
Algebra.

Source: Central American Olympiad 2001, problem 5

August 12, 2009
quadraticsfunctionarithmetic sequenceabsolute value

Problem Statement

Let a,b a,b and c c real numbers such that the equation ax^2\plus{}bx\plus{}c\equal{}0 has two distinct real solutions p1,p2 p_1,p_2 and the equation cx^2\plus{}bx\plus{}a\equal{}0 has two distinct real solutions q1,q2 q_1,q_2. We know that the numbers p1,q1,p2,q2 p_1,q_1,p_2,q_2 in that order, form an arithmetic progression. Show that a\plus{}c\equal{}0.