How to factor the polynomial $x^4-x^2 + 1$ How do I factor this polynomial: $$x^4-x^2+1$$
The solution is: $$(x^2-x\sqrt{3}+1)(x^2+x\sqrt{3}+1)$$
Can you please explain what method is used there and what methods can I use generally for 4th or 5th degree polynomials?

Take $x^2=t$, and then try to factor the polynomial $t^2-t+1$.
