Answer:
- 21
Step-by-step explanation:
The minimum value occurs at the vertex of the function
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
To obtain this form use the method of completing the square
Given
f(x) = x² - 6x - 12
add/ subtract ( half the coefficient of the x- term)² to x² - 6x
f(x) = x² + 2(- 3)x + 9 - 9 - 12
= (x - 3)² - 21
with vertex = (3, - 21 )
The minimum is the value of k, that is minimum value = - 21
