\[f(x) = - \frac{1}{4}x^{2} + 2x + 10 \Longrightarrow\]
\[\Longrightarrow ветви\ вниз.\]
\[x_{0} = \frac{- 2}{- \frac{2}{4}} = 4,\ \ y_{0} = 14.\]
\[E(f) = ( - \infty;14\rbrack,\]
\[возрастает\ \ на\ \ ( - \infty;4\rbrack,\ \]
\[убывает\ на\ \lbrack 4; + \infty).\]