The function f(x) = 3x^3 + 9x + 1. The extreme values of f(x) lie at points that are the solution of the equation f'(x) = 0
f'(x) = 9x^2 + 9
f'(x) = 0
=> 9x^2 + 9 = 0
=> x^2 = -1
This equation does not have a real solution.
The given function does not have any extreme points. It can take on nay value in the set `(-oo, oo)`