\[y = x² - 2x - 3\]
| \[x\] | \[- 2\] | \[- 1\] | \[0\] | \[1\] | \[2\] | \[3\] |
|---|---|---|---|---|---|---|
| \[y\] | \[5\] | \[0\] | \[- 3\] | \[- 4\] | \[- 3\] | \[0\] |
\[x_{b} = - \frac{b}{2a} = \frac{2}{2} = 1\]
\[y_{b} = - 4\]

\[y
earrow \ \ при\ x \in \lbrack 1; + \infty)\]
\[y \searrow \ \ при\ x \in ( - \infty;1\rbrack\]