How does the zero factor property relate to factoring a polynomial?

1 Answer
Sep 24, 2015

Well, if you a polynomial is factorable then its roots/zeroes can be easily found by setting it to zero and using the zero factor property. Please see explanation below.

Explanation:

The Zero Product Property:
A product of factors is zero if and only if one or more of the factors is zero. Or:
if a*b = 0, then either a = 0 or b = 0 or both.
Example: Find the roots of the polynomial by factoring:
P(x) = x^3-x^2-x+1, set to zero:
x^3-x^2-x+1=0, factor by grouping:
x^2(x-1)-1(x-1)=0
(x^2-1)(x-1)=0, use difference of squares to factor further:
(x+1)(x-1)(x-1)=0, use the zero factor property:
x+1=0=>x=-1
x-1=0=>x=1
Notice that x = 1 has a multiplicity of 2.