新GRE数学要点:Finding Real Roots

会计考友

Finding Real Roots 　　If (x-c) is a factor of the polynomial p(x), then c is a root of p(x).
　　We can find the real roots of polynomial p(x) by finding all the factors of p(x).
5 [- t1 z$ l5 y" O$ T1 J$ c  H4 B　　Example:
: n* K: Y3 {! G. ?3 K　　p(x)=x2+3x+2=(x+1)(x+2). Two real roots of p(x) are -1 and -2.
　　Remember:
% m9 s/ y) J4 B8 h9 @& }　　To find if c is a root of p(x), evaluate p(c) and check if p(c)=0.
! q+ V* F$ o, _2 u' V5 W% P　　If x is a common factor of p(x), then zero is a root of p(x).
# D' r. A3 u3 \& z5 E　　由于美国数学基础教育的难度增加导致数学考试越来越难，但新gre数学复习考点都是高中时候学到的知识点，考生不要过于紧张，把基本概念弄明白，再记住一些新版gre数学必备的词汇，那么相信新版gre数学应该没有问题。