Answer:
f(x) = [x – (4 + √20)][x – (4 – √20]
Step-by-step explanation:
In order to know the function that best describes the given f(x) that best reveals it's minimum or maximum, we need to know solve for x.
x² – 8x – 4 = 0
Using completing the square method
x² – 8x = 4
x² – 8x + 4² = 4 + 4²
(x – 4)² = 20
x = 4 ±√20
Therefore
f(x) = [x – (4 + √20)][x – (4 – √20]
