How do you factor h(x)=x^3-3x^2-x+3?

1 Answer
Dec 19, 2015

Factor by grouping then using the difference of squares identity to find:

x^3-3x^2-x+3 =0 =(x-1)(x+1)(x-3)

Explanation:

The difference of squares identity may be written:

a^2-b^2 = (a-b)(a+b)

After factoring by grouping use this identity with a=x and b=1...

x^3-3x^2-x+3

=(x^3-3x^2)-(x-3)

=x^2(x-3)-1(x-3)

=(x^2-1)(x-3)

=(x^2-1^2)(x-3)

=(x-1)(x+1)(x-3)