Answer:
D
Step-by-step explanation:
The maximum value is the y- coordinate of the vertex
Given a quadratic in standard form , y = ax² + bx + c ( a ≠ 0 )
Then the x- coordinate of the vertex is
x = - [tex]\frac{b}{2a}[/tex]
y = - x² + 6x + 5 ← is in standard form
with a = - 1 and b = 6 , then x- coordinate of vertex is
x = - [tex]\frac{6}{-2}[/tex] = 3
Substitute x = 3 into the function for y- coordinate of vertex
y = - 3² + 6(3) + 5 = - 9 + 18 + 5 = 14
maximum value is 14 → D
