代数方程式
ただし、 { p = − 1 3 ( b a ) 2 + c a q = 2 ( b 3 a ) 3 − b c 3 a 2 + d a ω = − 1 + 3 i 2 {\displaystyle {\begin{cases}p=-{1 \over 3}\left({b \over a}\right)^{2}+{c \over a}\\q=2\left({b \over 3a}\right)^{3}-{bc \over 3a^{2}}+{d \over a}\\\omega ={-1+{\sqrt {3}}i \over 2}\end{cases}}}