Answer:
vertex = (1, - 9 )
Step-by-step explanation:
The x- coordinate of the vertex is at the midpoint of the zeros.
Given
f(x) = (x - 4)(x + 2)
Find the zeros by letting f(x) = 0 , that is
(x - 4)(x + 2) = 0
Equate each factor to zero and solve for x
x + 2 = 0 ⇒ x = - 2
x - 4 = 0 ⇒ x = 4
Then
[tex]x_{vertex}[/tex] = [tex]\frac{-2+4}{2}[/tex] = [tex]\frac{2}{2}[/tex] = 1
Substitute x = 1 into f(x) for corresponding y- coordinate
f(1) = (1 - 4)(1 + 2) = (- 3)(3) = - 9
Vertex = (1, - 9 )
