26. Incorrect. The answer is false, not true. To find the optimal point set the first derivative of f'(x) = 0, or f'(x) = 2x - 12 = 0. From this x₀ = 6. To determine whether the optimal point is a relative/global maximum of minimum or neither, check the sign of the second derivative evaluated at the optimal point: f"(x) = 2 for all values of x, therefore, x₀ is a global minimum.