Решите уравнение: y^6+4y^4=y^2+4.

\[y^{6} + 4y^{4} = y^{2} + 4\]

\[y^{4}\left( y^{2} + 4 \right) - \left( y^{2} + 4 \right) = 0\]

\[\left( y^{2} + 4 \right)\left( y^{4} - 1 \right) = 0\]

\[y^{2} = - 4;\ \ \ \ \ \ \ \ \ \ \ \ \ \ y^{4} = 1\]

\[нет\ корней;\ \ \ \ \ \ y = \pm 1\]

\[Ответ:\ \ y = \pm 1.\]