1) Cho ham so f(x) co dao ham cap 2 tren R. Xet cac khang dinh sau
i) Neu ham so f(x) dat cuc tieu tai x = xo thi \(\left\{{}\begin{matrix}f'\left(x_o\right)=0\\f''\left(x_o>0\right)\end{matrix}\right.\)
ii) Neu ham so f(x) dat cuc dai tai x = xo thi \(\left\{{}\begin{matrix}f'\left(x_o\right)=0\\f''\left(x_o\right)< 0\end{matrix}\right.\)
iii) Neu f''(xo) = 0 thi ham so f(x) khong dat cuc tri tai x = xo
So khang dinh dung trong cac khang dinh tren la:
A. 0 B. 1 C. 2 D.3