Answer:
y - value of the vertex is 49.
Explanation:
Given function is f(x) = -(x - 3)(x + 11)
f(x) = -(x² - 3x + 11x - 33)
= -(x² + 8x - 33)
= -(x² + 8x + 16 - 49)
= -[(x + 4)² - 49]
= -(x + 4)² + 49
Comparing this equation with the vertex form of a quadratic function,
f(x) = -(x - h)² + k
Where (h, k) is the vertex of the function.
Vertex of the parabola is (-4, 49)
Therefore, y-value of the vertex is 49.