\[y = 3 - x^{2}.\]
\[1)\ a - абсцисса\ вершины:\]
\[b = 3 - a^{2} - ордината\ вершины.\]
\[2)\ S(a) = ab = a\left( 3 - a^{2} \right) =\]
\[= 3a - a^{3};\]
\[S^{'}(a) = 3 - 3a^{2}.\]
\[3)\ Промежуток\ возрастания:\]
\[3 - 3a^{2} \geq 0\]
\[3a^{2} - 3 \leq 0\]
\[3(a + 1)(a - 1) \leq 0\]
\[- 1 \leq a \leq 1.\]
\[4)\ Точка\ максимума:\]
\[a = 1;\]
\[b = 3 - 1 = 2.\]
\[S = ab = 1 \bullet 2 = 2.\]
\[Ответ:\ \ 2.\]