A rational function $f(x)$ is defined for all real numbers except for $x=-6$ and $x=10.$ We are given that $x=-6$ and $x=10$ are vertical asymptotes for $f(x).$ The first derivative of this function is given below:

$f^{\text{'}}(x)=\frac{x^2-1}{(x+6{)}^3(x-10{)}^3}$

List all local extreme points for $f(x).$