$$\left. \begin{array} { l } { y = x ^ { 6 } - 4 x ^ { 3 } } \end{array} \right.$$
$x\in \sqrt[3]{\sqrt{y+4}+2},e^{\frac{4\pi i}{3}}\sqrt[3]{\sqrt{y+4}+2},e^{\frac{2\pi i}{3}}\sqrt[3]{\sqrt{y+4}+2},e^{\frac{4\pi i}{3}}\sqrt[3]{-\sqrt{y+4}+2},\sqrt[3]{-\sqrt{y+4}+2},e^{\frac{2\pi i}{3}}\sqrt[3]{-\sqrt{y+4}+2}$
$x=\sqrt[3]{\sqrt{y+4}+2}$
$x=\sqrt[3]{-\sqrt{y+4}+2}\text{, }y\geq -4$
