### Home > A2C > Chapter 9 > Lesson 9.1.1 > Problem9-20

9-20.

Find the roots (the solutions when $y = 0$) of each of the following polynomial functions.

1. $y = x^{2} − 6x + 8$

Factor the right side and use the Zero Product Property.

$x = 2, x = 4$

b.$f\left(x\right) = x^{2} − 6x + 9$

See part (a).

$x = 3$

1. $y = x^{3} − 4x$

See part (a).

x is a common factor.