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HMMT 二月 2001 · 代数 · 第 7 题

HMMT February 2001 — Algebra — Problem 7

专题
Contest Math / 竞赛数学
难度
L3
来源
HMMT

题目详情

英文原题

  1. A polynomial P has four roots, , , 2 , 4. The product of the roots is 1, and P (1) = 1.
    4 2
    Find P (0).
解析

英文解析

  1. A polynomial P has four roots, , , 2 , 4. The product of the roots is 1, and P (1) = 1.
    4 2
    Find P (0).
    Solution: A polynomial Q with n roots, x , . . . , x , and Q ( x ) = 1 is given by Q ( x ) =
    1 n 0
    ( x − x )( x − x ) ··· ( x − x )
    1 2 n 1 8
    , so P (0) = = .
    3 1
    ( x − x )( x − x ) ··· ( x − x ) 9
    · · ( − 1) · ( − 3)
    0 1 0 2 0 4
    4 2