\[y = 4x^{2} - 1\]
\[4x^{2} - 1 = 0\]
\[4x^{2} = 1\]
\[x^{2} = \frac{1}{4}\]
\[x = \pm \frac{1}{2}.\]
\[Нули\ функции\ при\ x = \pm \frac{1}{2}.\]