新版GRE数学复习重要考点：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).

Example:

p(x)=x²+3x+2=(x+1)(x+2). Two real roots of p(x) are -1 and -2.

Remember:

To find if c is a root of p(x), evaluate p(c) and check if p(c)=0.

If x is a common factor of p(x), then zero is a root of p(x).