HMMT 二月 2003 · 冲刺赛 · 第 2 题
HMMT February 2003 — Guts Round — Problem 2
题目详情
- [5] The graph of x = x y is a union of n different lines. What is the value of n ?
解析
- The graph of x = x y is a union of n different lines. What is the value of n ? Solution: 3 4 2 2 2 The equation x − x y = 0 factors as x ( x + y )( x − y ) = 0, so its graph is the union of the three lines x = 0, x + y = 0, and x − y = 0.