Question: Find the second derivative of f(x) = x^3 - 6x^2 + 9x.
Options:
Correct Answer: 6
Solution:
f\'(x) = 3x^2 - 12x + 9; f\'\'(x) = 6x - 12. At x = 2, f\'\'(2) = 6(2) - 12 = 0.