HMMT 二月 2016 · 冲刺赛 · 第 1 题
HMMT February 2016 — Guts Round — Problem 1
题目详情
- [ 5 ] Let x and y be complex numbers such that x + y = 20 and x + y = 15. Compute | x − y | .
解析
- [ 5 ] Let x and y be complex numbers such that x + y = 20 and x + y = 15. Compute | x − y | . Proposed by: Evan Chen √ Answer: 10 √ 2 2 2 2 2 We have ( x − y ) + ( x + y ) = 2( x + y ), so ( x − y ) = 10, hence | x − y | = 10.