We have to find the value of x for which f(x) has a minimum.
Extreme values of f(x), like minimum or maximum values, correspond to values of its derivative equal to 0.
In this case f'(x) = 0 for x = -2 and x = 0.
We can find if this extreme value is a minimum if the second derivative f''(x) is greater than 0.
In this case, f'(x) = 0 and f''(x) > 1 for x = 0.
Then, x = 0 is a local minimum.
Answer: x = 0