How does
$\displaystyle 1 - 9x^{2} + 24x^{4} - 16x^{6}$
become
$\displaystyle (1 - x^{2})(16x^{4} - 8x^{2} + 1)$ ?
Hey Jason76.
You might want to look at this:
Rational root theorem - Wikipedia, the free encyclopedia
$\displaystyle 1 - 9x^{2} + 24x^{4} - 16x^{6}$
Pulling out x^{2}
$\displaystyle 1 - [x^{2}(9 + 24x^{2} - 16x^{4})]$
$\displaystyle (1 - x^{2})(9 + 24x^{2} - 16x^{4})$
After that, nothing in the right linear has any common factor, so you can't do anymore. But that's not the final answer.