Final answer:
The function f(x) is negative over the interval (-8, -2).
Step-by-step explanation:
The function f(x) is negative when the values of f(x) are less than zero. To determine the intervals over which f(x) is negative, we need to analyze the function and identify when it is less than zero.
From the given options, the interval (-8, -2) includes negative values for f(x) since it represents a range of x-values where the function is below the x-axis. Therefore, the correct answer is option a) (-8, -2).