HMMT 二月 2024 · ALGNT 赛 · 第 8 题
HMMT February 2024 — ALGNT Round — Problem 8
题目详情
- Let ζ = cos + i sin . Suppose a > b > c > d are positive integers satisfying 13 13 √ a b c d | ζ + ζ + ζ + ζ | = 3 . Compute the smallest possible value of 1000 a + 100 b + 10 c + d .
解析
- Let ζ = cos + i sin . Suppose a > b > c > d are positive integers satisfying 13 13 √ a b c d | ζ + ζ + ζ + ζ | = 3 . Compute the smallest possible value of 1000 a + 100 b + 10 c + d . Proposed by: Rishabh Das Answer: 7521 ′ ′ ′ a b c Solution: We may as well take d = 1 and shift the other variables down by d to get | ζ + ζ + ζ +1 | = √