Em tách riêng từng ý ra để hỏi nhé
\(\begin{array}{l}
1)\,D = R \Rightarrow \forall x \in D \Rightarrow - x \in D\\
f\left( { - x} \right) = \left( {2{{\left( { - x} \right)}^3} - \left( { - x} \right)} \right)\left( {{{\left( { - x} \right)}^2} - 1} \right)\\
= \left( { - 2{x^3} + x} \right)\left( {{x^2} - 1} \right)\\
= - \left( {2{x^3} - x} \right)\left( {{x^2} - 1} \right) = - f\left( x \right)\\
\Rightarrow \,Ham\,so\,le\\
2)\,D = R\backslash \left\{ {0;\frac{1}{2}; - \frac{1}{2}} \right\}\\
\Rightarrow \forall x \in D \Rightarrow - x \in D\\
f\left( { - x} \right) = \frac{{{{\left( { - x} \right)}^2} + 5}}{{4\left( { - x} \right) - {{\left( { - x} \right)}^3}}} = \frac{{{x^2} + 5}}{{ - 4x + {x^3}}} = - \frac{{{x^2} + 5}}{{4x - {x^3}}} = - f\left( x \right)\\
\Rightarrow \,Ham\,so\,le
\end{array}\)
