\[y = 3x^{4} - 4x^{2} + 1\]
\[y( - x) =\]
\[= 3 \cdot ( - x)^{4} - 4 \cdot ( - x)^{2} + 1 =\]
\[= 3x^{4} - 4x^{2} + 1\]
\[Так\ как\ y( - x) = y(x),то\ \ \]
\[\ f(x) - четная.\]