Answer:
vertex = (2, - 9 )
Step-by-step explanation:
Given a quadratic in standard form : ax² + bx + c : a ≠ 0
Then the x- coordinate of the vertex is
[tex]x_{vertex}[/tex] = - [tex]\frac{b}{2a}[/tex]
x² - 4x - 5 ← is in standard form
with a = 1, b = - 4, thus
[tex]x_{vertex}[/tex] = - [tex]\frac{-4}{2}[/tex] = 2
Substitute this value into the quadratic for corresponding value of y
(2)² - 4(2) - 5 = 4 - 8 - 5 = - 9
vertex = (2, - 9 )
