Hàm số

C

- Hướng dẫn giải

Đáp án C

Ta có: $y\text{'}=3x^2-6x\Rightarrow y\text{'}=0\iff \left[\begin{array}{l}x=0\\ x=2\end{array}\right..$ 

Mặt khác:

$y\text{'}\text{'}=6x-6\Rightarrow \left\{\begin{array}{l}y\text{'}\text{'}\left(0\right)=-6\\ y\text{'}\text{'}\left(2\right)=6\end{array}\right.\Rightarrow y_{CĐ}=y\left(0\right)=3.$