On page 248, it is shown how to solve the polynomial . In this note, I will explain how to solve the polynomial
First we multiply both sides by to get
Then since , we can divide some terms by
Now we let so we have
which after simplification becomes
Using the Rational Root Theorem (discussed on page 246) we quickly find that is a root and factor the polynomial as
Now the rest is simple! We can use the cubic solving method discussed on pages 247-248 to find the roots of
Then simple quadratic bashing gives us our roots!