Hàm số

B

- Hướng dẫn giải

Đáp án B

$\begin{array}{l}y=\frac{-2x^3+\text{}3x}{1-x}=2x^2+2x-1+\text{\hspace{0.17em}}\frac{1}{1-x}\\ y\text{'}=4x+\text{}2-\frac{1}{{(1-x)}^2}.(1-x)\text{'}=4x+2+\text{\hspace{0.17em}}\frac{1}{{(1-x)}^2}\\ y"=4-\frac{1}{{(1-x)}^4}\left[{(1- x)}^2\right]\text{'}=4-\frac{1}{{(1-x)}^4}.2(1-x).(-1)\\ =4+\text{\hspace{0.17em}\hspace{0.17em}}\frac{2}{{(1-x)}^3}\end{array}$