Найдите область значения функции y=-2x²+4x-7, если x∈[-1;2].

\[y = - 2x^{2} + 4x - 7;\ \ x \in \lbrack - 1;2\rbrack.\]

\[x = - 1:\]

\[y = - 2 \cdot 1 - 4 - 7 = - 13;\]

\[x = 2:\]

\[y = - 2 \cdot 4 + 8 - 7 = - 7;\]

\[x = 1:\]

\[y = - 2 \cdot 1 + 4 - 7 = - 5.\]

\[E(y) = \lbrack - 13; - 5\rbrack.\]