\[4x^{4} - 3x^{2} - 10 = 0\]
\[x^{2} = t \geq 0:\]
\[4t^{2} - 3t - 10 = 0\]
\[D = 9 + 40 = 49\]
\[t_{1} = \frac{3 + 7}{8} = 1;\]
\[t_{2} = \frac{3 - 7}{8} = - \frac{4}{8} < 0.\]
\[x^{2} = 1\]
\[x = \pm 1.\]
\[Ответ:x = \pm 1.\]