MathDB
2018 Fall Team #6

Source:

April 17, 2022
algebra

Problem Statement

Karina has a polynomial p1(x)=x2+x+kp_1(x) = x^2 + x + k, where kk is an integer. Noticing that p1p_1 has integer roots, she forms a new polynomial p2(x)=x2+a1x+b1p_2(x) = x^2 + a_1x + b_1, where a1a_1 and b1b_1 are the roots of p1p_1 and a1b1a_1 \ge b_1. The polynomial p2p_2 also has integer roots, so she forms a new polynomial p3(x)=x2+a2x+b2p_3(x) = x^2 + a_2x + b_2, where a2a_2 and b2b_2 are the roots of p2p_2 and a2b2a_2 \ge b_2. She continues this process until she reaches p7(x)p_7(x) and finds that it does not have integer roots. What is the largest possible value of kk?