How do you use the rational roots theorem to find all possible zeros of f(x)=x^3+x^2-8x-6 f(x)=x3+x28x6?

1 Answer
Mar 20, 2016

The Rational Root Theorem states: that the set (+-1, +-2, +-3, +-6) (±1,±2,±3,±6) constitute the set of all possible zero roots to f(x)f(x)

Explanation:

Given f(x) = a_n x^n + a_(n-1)x^(n-1) + cdots+ a_1x6+a_0=Sigma_(i=0)^n a_ix^i
let p and q be AA p: a_0|p and q: a_n|q,
then f(x) potential roots are x_i: x_i in (p_l/q_k)
where p_l and q_k are the l_(th) and k_(th) factors

a_0 = 6 => +-(1, 2, 3, 6)
a_3 = 1
Thus the Rational Root Theorem states:
that the set (+-1, +-2, +-3, +-6) constitute the set of all possible zero roots to f(x)