\[\boxed{\text{231}\text{\ (231)}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[y = ax^{2}\]
\[\textbf{а)}\ ax^{2} \geq 0\ \ \ при\ \ a \geq 0;\]
\[\textbf{б)}\ \ ax^{2} \leq 0\ \ при\ \ a \leq 0\text{.\ }\]