Answer:
(5, - 4)
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 - 10x + 21 ← is in standard form
with a = 1, b = - 10, so
[tex]x_{vertex}[/tex] = - [tex]\frac{-10}{2}[/tex] = 5
Substitute x = 5 into the quadratic for the corresponding value of y
y = 5² - 10(5) + 21 = 25 - 50 + 21 = - 4
vertex = (5, - 4)
