Určení funkční hodnoty

\( \large s \left( -\Large \frac{2}{7}\large \right) = 2 \)
\( \large s \left( -\Large \frac{2}{7}\large \right) = 0 \)
\( \large s \left( -\Large \frac{2}{7}\large \right) = 1 \)
\( \large s \left( -\Large \frac{2}{7}\large \right) = -1 \)