## Precalculus (6th Edition) Blitzer

$x= \pm 1, \pm 5$ or $x=-1,1,-5,5$
The Rational Root Test is defined as follows: When a polynomial $f(x)=a_nx^n+a_{n-1} x^{n-1} +....+a_2 x^2+a_1x+a_0$ has integer coefficients, then every rational zero of $f$ has the form $\dfrac{m}{n}$ where, $m$ and $n$ have no common factors other than $1$ and $m$ is a factor of the constant term $a_0$ and $n$ is a factor of the leading co-efficient term $a_n$. So, $f(x)=x^4-6x^3+14x^2-14x+5$ has possible rational roots: $x= \pm 1, \pm 5$ or $x=-1,1,-5,5$