f'(x)=3x^2-2x-1
x1,2=(2+-radical16)/6=(2+-4)/6
x1=-1/3 x2=1
f"(x) =6x-2=2(3x-1)
x |- ∞ -1/3 1/3 1 ∞
f(x) creste maxim scade minim creste
f'(x) ++++++++++++0 --------------------- 0+++++++++++++++
f'(x) -------------------------------------------0++++++++++++++++++++
CONCAVA pct.inflex CONVEXA
f(-1/3) =...vezi tu, minim LOCAL
f(1)=1 , maxim LOCAL
