Identify the stationary points of f(x)=3x^3+2x^2+4 (by finding the first and second derivative) and determine their nature.
f'(x)=9x2+4x, and f''(x)=18x+4 (derivatives)
f'(x)=0 at x=0 or x=-4/9
when x=0 f''(x)>0 therefore a minimum value, when x=-4/9 f''(x)<0 and thus a maximum value.
SO
