



 
Hi Dakota, I assume you used substitution to find a zero of $f(x),$ say $x = a,$ and then you divided $f(x)$ by $x  a$ to arrive at the cubic equation. You should check your work. You didn't tell us what zero you found but I think there is an error in your division. If you correct your error then you can use the same procedure again on the resulting cubic. Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 