Ответ:
\[y = - x^{2} + 2x + 3\]
| \[x\] | \[- 1\] | \[0\] | \[1\] | \[2\] | \[3\] |
|---|---|---|---|---|---|
| \[y\] | \[0\] | \[3\] | \[4\] | \[3\] | \[0\] |
\[x_{b} = - \frac{b}{2a} = \frac{- 2}{- 2} = 1\]
\[y_{b} = - 1 + 2 + 3 = 4\]

\[y_{\max} = 4\]
\[y = - x^{2} + 2x + 3\]
| \[x\] | \[- 1\] | \[0\] | \[1\] | \[2\] | \[3\] |
|---|---|---|---|---|---|
| \[y\] | \[0\] | \[3\] | \[4\] | \[3\] | \[0\] |
\[x_{b} = - \frac{b}{2a} = \frac{- 2}{- 2} = 1\]
\[y_{b} = - 1 + 2 + 3 = 4\]

\[y_{\max} = 4\]