\[3x^{4} - 5x^{2} + 2 = 0\]
\[x^{2} = y \geq 0:\]
\[3y^{2} - 5y + 2 = 0\]
\[D = 25 - 24 = 1\]
\[y_{1} = \frac{5 + 1}{6} = 1;\ \]
\[y_{2} = \frac{5 - 1}{6} = \frac{4}{6} = \frac{2}{3}.\]
\[1)\ x^{2} = 1\]
\[x = \pm 1.\]
\[2)\ x^{2} = \frac{2}{3}\]
\[x = \pm \sqrt{\frac{2}{3}} = \pm \frac{\sqrt{6}}{3}.\]
\[Ответ:x = \pm \frac{\sqrt{6}}{3};\ \ x = \pm 1.\]