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Harvard-MIT Mathematics Tournament #0iyq

Harvard-MIT Mathematics TournamentHard

From module Advanced Inequalities

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Understand the scale
Scale 0.5: Easiest math competition problems, often solvable even for early middle school students without experience. 1: Problems strictly for beginners, often at a moderate middle school level. 1.5: Problems for stronger beginner students, on the level of the middling problems in most middle school contests. 2: For motivated beginners, harder questions from the previous categories. 2.5: More advanced beginner problems, hardest questions from previous categories. 3: Early intermediate problems that require more creative thinking. 3.5: Tougher early intermediate problems that consistently stretch into higher-level creative thinking or conceptual knowledge. 4: Intermediate-level problems. 4.5: Upper intermediate problems approaching the upper bound for non-invitational sprint math competitions. 5: More difficult AIME problems or simple proof-based Olympiad-style problems. 6: High-level AIME-styled questions or introductory Olympiad-level questions. 7: Tougher Olympiad-level questions, may require more technical knowledge. 8: High-level Olympiad-level questions. 9: Expert Olympiad-level questions. 9.5: The hardest problems appearing on Olympiads which the strongest students could reasonably solve. 10: Historically notorious problems, generally unsuitable for even very hard competitions because they are exceedingly tedious, long, and difficult.
Polynomial operationsSymmetric functionsVieta's formulasIntermediate Value TheoremMuirhead / majorization

Problem

Problem: Let f(x)=x4+14x3+52x2+56x+16f(x) = x^{4} + 14 x^{3} + 52 x^{2} + 56 x + 16. Let z1,z2,z3,z4z_{1}, z_{2}, z_{3}, z_{4} be the four roots of ff. Find the smallest possible value of ∣zazb+zczd∣\left|z_{a} z_{b} + z_{c} z_{d}\right| where {a,b,c,d}={1,2,3,4}\{a, b, c, d\} = \{1,2,3,4\}.

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