# Thread: Equation order 8 in C :

1. ## Equation order 8 in C :

Solve in R :

2. Originally Posted by dhiab
Solve in R :
$z^8-z^6=z^6(z^2-1)$

So $z^8-z^6-z^2+1=(z^2-1)(z^6-1)=(z-1)(z+1)(z^3-1)(z^3+1)$
$=(z-1)^2(z+1)^2(z^2+z+1)(z^2-z+1)$

3. Originally Posted by dhiab
Solve in R :
$z^8-z^6+z^2-1=0$

$(z^6+1)(z^2-1)=0$

now, it can be solved using Demoivres theorem.